What is Biology?

1
What is Biology?

• Science A way of using organized evidence to
  learn about the natural world.
• Biology The branch of science that deals with
  living things.

2
So.what are living things?

• Living things
• Are made up of cells.
• Reproduce.
• Sexually (humans)
• Asexually (bacteria)
• Are based on a genetic code.
• Grow.

3
So.what are living things?

• Living things
• Obtain and use nutrients and energy.
• Photosynthesis Cellular Respiration
• Respond to their environment.
• Maintain a stable internal environment.
• Homeostasis
• Change over time.
• Evolution!!!

4
What is the Scientific Method?

• 1) Question
• 2) Hypothesis
• It must be TESTABLE!!!

5
What is the Scientific Method?

• 3) Experiment
• Procedure (step-by-step)
• Controls
• What stays the same.
• Independent Variables
• What you change.ONE THING ONLY!!!
• Dependent Variables
• What happens based on your experimental
  design.the results.

6
What is the Scientific Method?

• 4) Observations
• Qualitative.a description.
• The bread is cold.
• Quantitative.a measurement.
• The bread is 12.4 degrees Celsius.
• 5) Results
• 6) Conclusion (based on facts) vs. Inference
  (based on opinions and unobserved information)

7
What are the major levels of organization of
living things?

• 1) Atomsnot living.
• Hydrogen, Helium, Oxygen
• 2) Moleculesnot living.
• Water, Ammonia, Carbon Dioxide
• 3) Cellssmallest unit of life.
• Brain cell, bacteria

8
What are the major levels of organization of
living things?

• 4) Groups of cells
• Tissue, organ, organ system.
• 5) Organism
• Human, Bison, Sunflower
• 6) Population group of ONE organism
• Herd of buffalo, field of sunflowers

9
What are the major levels of organization of
living things?

• 7) Communitypopulations of different organisms
  living together
• Herd of bison AND a field of sunflowers.
• 8) Ecosystemcommunity (living things) AND
  non-living surroundings
• Bison herd, sunflower field, soil, air, water.
• 9) Biospherethe Earth!

10
Section 3.1

• Review Levels of Organization
• Individual Organism
• Population
• Community
• Ecosystem
• Biome
• Biosphere

11
How does energy flow?

• All energy originates from SUNLIGHT or CHEMICAL
  COMPOUNDS.
• Autotrophs use energy from sunlight or
  chemicals to produce food.
• Also called PRODUCERS

12
How does energy flow?

• Photosynthesis the chemical process that uses
  energy from sunlight to convert H2O and CO2 to
  sugar and O2
• Plants, algae
• Chemosynthesis the process that uses energy
  from chemicals to create carbohydrates.without
  light!
• Bacteria that live in ocean floor vents

13
How does energy flow?

• Heterotrophs organisms that rely on other
  organisms for their energy
• Also called CONSUMERS
• Herbivores plant-eaters
• Carnivores meat-eaters
• Omnivores eat plants AND meat
• Detrivores feed on dead plant/animal matter
• Decomposers break down organic matter

14
How does energy flow?

• Food chain displays the one-way energy flow
  from sun (or chemicals) to autotrophs to
  heterotrophs
• Sun ? producer ? 1st-level consumer ? 2nd-level
  consumer ? 3rd-level consumer

15
How does energy flow?

• Food web More realistic way of representing
  energy flow in natureshows complex feeding
  relationships

16
What are trophic levels?

• 1st trophic level PRODUCERS
• 2nd trophic level Primary (1st-level) consumers
• 3rd trophic level Secondary (2nd-level)
  consumers
• And so on.

17
What are energy pyramids?

• Only PART of the total energy from one trophic
  level is passed on to the next trophic level
  within a food web.
• (approximately 10 is passed on within each
  transfer)
• Corn75 units of energy
• Cow7.5 units of energy
• Human0.75 units of energy

18

19
Where does all of the lost energy go?

• The lost energy (90 of the total at each
  trophic level) is used in two ways
• 1) Used as energy for life processes
• Growing, Reproducing, Moving, etc.
• 2) Lost as heat

20
What is a biomass pyramid?

• Biomass the total amount of living tissue
  within a given trophic level
• This pyramid also usually is reduced by a factor
  of ten at each trophic level.
• 500,000 g of corn (plant tissue)
• 50,000 g of cows (1st-level consumer tissue)
• 5,000 g of human tissue

21
How are energy pyramids related to biomass
pyramids?

• Because each trophic level harvests only about
  1/10th of the energy from the level below, it can
  support only about 1/10th the amount of living
  tissue.

22
How is the movement of matter different from the
movement of energy within an ecosystem?

• Energy flows in ONE DIRECTION!!
• Matter is RECYCLED!!

23
How is water cycled?

• Evaporation Liquid to gas
• Condensation Gas to liquid
• Precipitation Liquid in atmosphere to liquid on
  ground

24
How is water cycled?

• Runoff Liquid remains on surface
• Seepage Water soaks into ground
• Transpiration Liquid IN PLANTS to gas IN
  ATMOSPHERE (evaporation through leaves)

25
How is carbon cycled?

• Refer to p. 54-55 in your textbook.
• Photosynthesis takes carbon out of atmosphere
• Respiration releases carbon into atmosphere
• Human activities release (excess) carbon into
  atmosphere

26
What shapes an ecosystem?

• Biotic factors biological influences on an
  organism
• Predators, prey, population overcrowding
• Abiotic factors physical (non-living)
  influences on an organism
• Temperature, soil, precipitation, sunlight

27
What shapes an ecosystem?

• Together, BIOTIC and ABIOTIC factors determine
  the survival and growth of organisms within an
  ecosystem.

28
What is a habitat? A niche?

• Habitat The area where an organism lives.
• Niche The role of an organism within a given
  ecosystem.

29
What is a niche?

• The niche of a bullfrog
• Eats? insects, minnows
• Is eaten by? snakes, raccoons, birds
• Lives? In or near lakes or streams
• Adapts by? burrowing in pond mud to hibernate
• Reproduces by? laying eggs in water during warm
  months

30
What is a niche?

• NO TWO SPECIES CAN OCCUPY THE SAME NICHE AT THE
  SAME TIME IN THE SAME ECOSYSTEM!!!
• This is the Competitive Exclusion Principle!

31
What are the 3 major interactions within an
ecosystem?

• 1) Competition
• Two organisms fighting for use of a single
  resource at the same place at the same timeone
  of them will lose and not survive.

32
What are the 3 major interactions within an
ecosystem?

• 2) Predation
• One organism kills and feeds on another organism.

33
What are the 3 major interactions within an
ecosystem?

• 3) Symbiosis
• Mutualism
• Both species benefit (Bird Rhino)
• Commensalism
• One benefits, one doesnt care (Remora Shark)
• Parasitism
• One benefits, one is harmed (Fleas/Ticks/Worms
  Dog)

34
What is succession?

• Succession the predictable series of changes
  experienced by an ecosystem over time.

35
What is primary succession?

• Primary succession Succession that begins with
  BARE ROCK.
• Pioneer species (usually lichens) ? small grasses
  ? shrubs ? trees

36
What is secondary succession?

• Secondary succession Succession that begins with
  SOILusually after a disturbance (farming, forest
  fire, etc.)

37
What are major characteristics of populations?

• 1) Geographic distribution
• Where does the population live?
• 2) Population density
• How crowded is the population?
• 3) Growth rate
• How fast does the population grow?
• 4) Age structure
• How old (or young) is the entire population?

38
What factors affect growth rate?

• Three factors affect growth rate
• 1) Birth rate
• 2) Death rate
• 3) Emigration/Immigration
• Emigration individuals leaving the populated
  area
• Immigration individuals entering the area

39
HOW do populations grow?

• There are 2 general patterns in which populations
  of organisms can grow.
• 1) Exponential Growth
• 2) Logistic Growth

40
What is exponential growth?

• Exponential growth (J-curve) Individuals within
  a population grow at a constant rate over time.
• NEED
• Limitless food
• Limitless water
• Limitless space
• No predators
• No disease

41
What is logistic growth?

• Logistic growth (S-curve) Occurs when a
  populations growth slows or stops after a period
  of exponential growth.
• Growth slows or
• stops when food,
• shelter, etc. become
• less available!

42
What is logistic growth?

• For a given population, growth slows or stops
  near a certain number. This number varies within
  every environment, based on the amount of
  resources available within that environment.
• This number of individuals that a given
  environment can support is called the CARRYING
  CAPACITY!!

43
What is logistic growth?

• What affects carrying capacity? BIOTIC and
  ABIOTIC factors!!!
• Temperature
• Precipitation
• Shelter
• Food
• Disease

44
What limits populations during logistic growth?

• Limiting factors cause the growth of a
  population to slow or stop
• 1) Competition
• 2) Predation
• 3) Parasitism and disease
• 4) Drought and other climate factors
• 5) Human disturbance

45
What are density-dependent limiting factors?

• Density-dependent factor a limiting factor that
  depends on POPULATION DENSITY!
• Competitionfor food, water, space, sunlight
• Predationdeer / moose-wolf example
• Disease
• Anything else related to overcrowding!!

46
What are density-independent limiting factors?

• Density-independent factor a limiting factor
  that affects all populations in the same ways,
  regardless of the density of the population.
• Weather (floods, storms, etc.)
• Natural disasters
• Human activities (roads, logging, dams, etc.)

47
What are age structure diagrams?

• Age structure diagrams display the numbers of
  people within different age groups in a
  population.
• Good predictor of future population growth!

48

49

• P. 62-63 1-8, 13-15, 17-22
• Read p. 132-134
• p. 136-137 5, 10-12

50
What is demography?

• Demography the study of human populations

51
What is happening to the human population?

• From 10,000 B.C. until 1500 A.D., growth was very
  slow.
• From 1500-2006 (and especially 1800-2006), growth
  has been exponential!!
• WHY?
• Agriculture
• Industry/Technology
• Health care

52
What is happening to the human population?

• As societies become more modern, increase their
  level of education, and raise their standard of
  living, birth rates fall AND death rates fall.
• When the birth rate is LOWER than the death rate,
  population growth stops, and that population has
  undergone the demographic transition.

53
What is happening to the human population?

• Areas such as JAPAN, UNITED STATES, and EUROPE
  have completed the demographic transition.
• Many areas within AFRICA, ASIA, and SOUTH AMERICA
  have NOTtheir populations are still growing
  rapidly!!

54
How do humans affect the biosphere?

• Humans affect the biosphere by
• Hunting and gathering
• Agriculture
• Industry
• Urban Development

55
What developments have led to human population
growth?

• Agriculture provided sustainable food resources
  for large amounts of people
• Green Revolution Use of chemical fertilizers,
  pesticides, and modern techniques to greatly
  increase the worlds food supply.
• Industry/Urban Development More technology
  easier life longer life span and more babies!!

56
What are natural resources?

• Renewable resources regenerate (alive) OR
  replenished by matter cycles
• Wood
• Water
• Nitrogen
• Nonrenewable resources cannot be replenished
  naturally
• Oil
• Gas
• Coal

57
What are natural resources?

• Nonrenewable resources are running out as more
  and more people use them!!
• Renewable resources can also be severely damaged
  in both quality and quantity as more and more
  people use themwater pollution, deforestation,
  etc.

58
What are natural resources?

• How do we use resources responsibly?
• Sustainable development Using natural resources
  responsibly without depleting them or reducing
  their quality

59
What are natural resources?

• Types of resources include
• Land resources coal, oil, soil
• Forest resources trees, animals
• Fishery resources fish
• Air resources O2 ( ozone/greenhouse layer)
• Freshwater resources drinking water, animals
• ALL of these can be negatively affected by human
  development and activity!!!

60
What is biodiversity?

• Biodiversity biological diversity
  (diversitydifferences)
• Species diversity
• Ecosystem diversity
• Genetic diversity
• The MORE biodiversity, the BETTER!!

61
What threatens biodiversity?

• The following factors threaten biodiversity
• Habitat reduction or fragmentation
• Overhunting/fishing
• Pollution
• Invasive species(kudzu, zebra mussels, etc.)
• Ozone depletion more UV rays hitting Earth
  (from CFCs)
• Global warming

62
What is the greenhouse effect?

• Greenhouse effect the situation in which solar
  heat is retained by a layer of greenhouse gases
  to warm the Earth and maintain a constant
  temperature.
• Greenhouse gases include
• Carbon dioxide
• Methane
• Water vapor

63
Is the greenhouse effect bad?

• NO!!! Under normal circumstances, the greenhouse
  effect is not bad.
• BUT, because air pollution is making the
  blanket of greenhouse gases thicker, MORE heat
  is being trapped inside the Earth, leading to
  GLOBAL WARMING.

64
What else affects climate?

• 1) Latitude
• The angle of sunlight is more DIRECT at the
  equator, and therefore this zone is warmer.
• Tropical Zone Direct sunlight...hot
• Temperate Zone Moderate sunlightseasonal
  temperature changes
• Polar Zone Very angled, indirect sunlightcold

65
What else affects climate?

• 2) Winds
• 3) Ocean currents
• Both rely on the following principle
• Hot air/water RISES
• Cold air/water SINKS

66
What are the 4 states of matter?

• Solid arranged in a DEFINITE PATTERN, with a
  definite shape and a definite volume that never
  changes.
• Liquid have a definite volume that never
  changes, but does NOT have a definite shape

67
What are the 4 states of matter?

• Gas particles move very fast and can be very
  spread outhave no definite shape AND no definite
  volume (they can expand and shrink)
• Plasma gases heated to above 5000o C. Electrons
  are knocked away from the atoms because they
  collide very violently.

68
What is the basis of chemistry?

• The atom unable to be cut the basic unit of
  matter
• Proton ()
• Within nucleus
• Neutron (O)
• Within nucleus
• Approximately the same mass of a proton.
• Electron (-)
• Orbits around nucleus
• 1/1840 the mass of a proton!!!

69
What is the Periodic Table?

• Atomic Number
• of protons in an atom
• Mass Number
• of protons of neutrons in an atom
• The Periodic Table is organized numerically by
  atomic number.

70
What are atoms?

• Atoms (elements) are usually NEUTRALthey have
  the same number of protons as electrons. One
  atom makes up a specific ELEMENT, which cannot be
  broken down into smaller parts.
• Isotopes have different numbers of neutrons than
  regular elements.
• Therefore, they have a different mass number!!!
• Ions have different numbers of electrons than
  regular elements.

71
What is a compound?

• A chemical compound is a substance formed by the
  chemical combination of two or more elements.
• NaCl
• H2O
• The MOLECULE is the smallest unit of compounds.

72
What are the two types of chemical bonds?

• Ionic Bonds
• Electrons are TRANSFERRED between atoms.
• vs. attraction
• Covalent Bonds
• Electrons are SHARED between atoms.

73
What happens when compound combine?

• Mixture Salt and Pepper
• Can be PHYSICALLY separated!!!
• Solution Saltwater (dissolved particles)
• Solutesalt
• Solventwater
• Suspension Blood (undissolved particles)

74
What are acids, bases, and pHs?

• In a solution, H20 dissolves to form H and OH-
  ions.
• pH measures the ratio of H to OH- ions in a
  solution.

75
What are acids, bases, and pHs?

• Acid
• pH 0.1 to 6.9
• More H ions than OH- ions
• Base
• pH 7.1 to 14
• More OH- ions than H ions

76
What are acids, bases, and pHs?

• Neutral Substance
• pH 7
• H and OH- concentration is equal
• Buffer
• Maintains homeostasis by controlling sudden pH
  changes.

77
What is carbon?

• All living things on Earth are primarily composed
  of CARBON (and water).
• WHY?
• It is very easy for the carbon atom to form bonds
  with other carbon atoms and with many other
  different elements.
• Therefore, carbon is an ingredient in MANY
  natural molecules.also called ORGANIC MOLECULES.

78
What is a macromolecule?

• Macromolecule giant molecule
• Most macromolecules are based upon carbon and are
  called polymers.
• Monomers (small units) join together to make
  polymers (large unitschains).

79
What are the 4 major natural polymers?

• Carbohydrates
• Lipids
• Nucleic Acids
• Proteins

80
What are carbohydrates?

• Carbohydrates composed of C, H, O.
• Used as an energy source for living things.
• 3 categories
• Monosaccharidesglucose, fructose
• Disaccharides-- sucrose
• Polysaccharides glycogen, starch, cellulose

81
What are lipids?

• Lipids composed of mostly C, H.
• Not soluble in water.
• Used as energy storage for living things.
• Part of the cell membrane for animal cells.
• Made up of FATTY ACIDS and GLYCEROL
• Three categories
• Fats
• Oils
• Waxes

82
What are nucleic acids?

• Nucleic acids composed of H, N, O, C, P.
• Molecules are called nucleotides.
• Used as storage and transfer device for genetic
  information.
• Two categories
• DNA (deoxyribonucleic acid)
• RNA (ribonucleic acid)

83
What are proteins?

• Proteins composed of N, C, H, O.
• Made up of chains of AMINO ACIDS.
• These chains are joined by PEPTIDE BONDS.
• Used for
• regulation of cell processes
• formation of bones/muscles
• transportation of substances
• fighting disease
• cell structure components
• enzymes

84
How do chemical reactions work?

• Chemical reaction process that changes one set
  of chemicals to another set of chemicals by
  breaking bonds and forming new ones.
• You START with reactants.
• You FINISH with products.

85
What are some examples of chemical reactions?

• 2H2 O2 ? 2H2O
• 6H2O 6CO2 ? C6H12O6 6O2
• CH3CO2H NaHCO3 ? CO2 NaCO3 H2O

86
What is activation energy?

• Activation energy the energy needed to start a
  chemical reaction
• Catalysts speed up chemical reactions by
  reducing the amount of activation energy needed
  to start them

87
What are enzymes?

• Enzymes proteins that are natural catalysts!!!
• Enzymes provide a site for a chemical reaction to
  take place.

88
How does an enzyme-influenced chemical reaction
occur?

• 1-- Reactants (called SUBSTRATES) bind to the
  ACTIVE SITE of an enzyme.
• 2-- (Sped-up) chemical reaction takes place.
• 3-- Products are released from the enzyme.

89
How does an enzyme-influenced chemical reaction
occur?

• Substrate Key
• Enzyme Lock
• Active Site Keyhole within the lock

90
(7.1) How were cells discovered?

• Robert Hooke (1665) First microscopelooked at
  cork and discovered tiny, empty chambersPLANT
  CELLS!!
• Anton van Leeuwenhoek (1665-ish) First used
  microscope to observe LIVING cells in pond water.

91
What is the cell theory?

• By 1839, scientists concluded that all plants and
  animals were made of cells.
• This discovery (and related discoveries) led to
  the formation of the cell theory
• 1) All living things are made of cells.
• 2) Cells are the basic units of structure and
  function in living things.
• 3) New cells are produced from existing cells.

92
How are cells investigated today?

• Fluorescent labels of cell components.
• 3-D imaging.
• Electron microscopes (3-D and 1000X more
  magnified than light microscopes).

93
What is the difference between prokaryotes and
eukaryotes?

• Eukaryotes cells that contain a nucleus
• Larger and more complex
• Genetic material (DNA) is inside nucleus
• Contain organelles
• Plants, animals, fungi, protists

94
What is the difference between prokaryotes and
eukaryotes?

• Prokaryotes cells that do not contain a nucleus
• Smaller and simpler
• Have genetic material (DNA), but not inside a
  nucleus
• Usually no organelles, except ribosomes
• Bacteria

95
(7.2) What are organelles?

• Organelles tiny organssmall structures
  within cells (eukaryotes) that perform specific
  functions
• Reside in the cytoplasm
• Cytoplasm portion inside the cell that is
  OUTSIDE the nucleus

96
Organelle Overview

• 1) Nucleus Contains DNA to provide instructions
  for cell functions.
• 2) Ribosomes Small spheres on which proteins
  are assembled.
• 3) Endoplasmic Reticulum Ribosomes reside on
  the rough ER lipids are made on smooth ER

97
Organelle Overview

• 4) Golgi apparatus Modifies, sorts, and
  packages proteins and other cell products for
  storage or export.
• 5) Lysosomes Filled with enzymes to break down
  food (or waste) products.
• 6) Vacuoles Storage tanks for food/water.

98
Organelle Overview

• 7a) Mitochondria (animal/plant cells) convert
  food into energy.
• Contain their own DNA.
• 7b) Chloroplasts (plant cells) convert sunlight
  into food
• Contain their own DNA.

99
Organelle Overview

• 8) Cytoskeleton help provide shape and
  structure to the cell.
• Microfilaments provide tough, flexible support
• Microtubules assist in cell division AND cell
  transportation through CILIA and FLAGELLA

100
What is the endosymbiotic theory?

• Endosymbiotic theory Since mitochondria and
  chloroplasts have their own DNA, they were likely
  prokaryotes (separate cells) that formed a
  symbiotic relationship with larger eukaryotes and
  resided inside eukaryotic cells. Later, these
  prokaryotic cells just evolved into organelles
  (mitochondria and chloroplasts).

101
(7.3) What is the function of the cell membrane?

• Cell membrane regulates what enters and leaves
  the cell (and how much of it)
• Provides protection
• Provides support
• Lipid Bilayer
• Contains protein channels to allow for passing of
  materials

102
What is a cell wall?

• Cell wall provides support and protection for
  the cell
• Only in plants, fungi, and some prokaryotes
• Very rigid
• Carbohydrate and protein composition
• Very porous, so cannot regulate anything that
  passes through.

103
(7.4) How do cells make organisms?

• Unicellular organisms a single cell that IS an
  organism!
• Multicellular organisms organisms made up of
  many SPECIALIZED cells
• Blood cells (oxygen transport)
• Pancreatic cells (enzymes for food digestion)
• Muscle cells (movement)

104
How do cells make organisms?

• Plants have many different types of specialized
  cells too
• Guard cells (regulate gas exchange)
• Vascular cells (water/nutrient transport)

105
What are the major levels of organization in
living things?

• 1) Cell
• 2) Tissue
• 3) Organ
• 4) Organ System

106
What are the major levels of organization in
living things?

• Tissue groups of similar cells
• Organ groups of similar tissues
• Organ system groups of similar organs
• Specialized cells WORK TOGETHER to allow organ
  systems to work and INTERACT to allow all bodily
  processes to function!!!

107
(7.3) What is the function of the cell membrane?

• Cell membrane regulates what enters and leaves
  the cell (and how much of it)
• Provides protection
• Provides support
• Lipid Bilayer
• Contains protein channels to allow for passing of
  materials

108
What is a cell wall?

• Cell wall provides support and protection for
  the cell
• Only in plants, fungi, and some prokaryotes
• Very rigid
• Carbohydrate and protein composition
• Very porous, so cannot regulate anything that
  passes through.

109
What is diffusion?

• Every living cell NEEDS to exist in a very exact
  liquid environment, or it will DIE.
• Concentration mass of particles in a volume of
  liquid
• 12 g salt in 6 L water ? 2 g/L

110
What is diffusion?

• Diffusion movement of particles from an area of
  higher concentration to an area of lower
  concentration
• Diffusion stops only when a cell system has
  reached equilibrium.

111
What is diffusion?

• Diffusion does NOT require any energy from the
  cell, therefore is called passive transport.

112
What is osmosis?

• Osmosis the diffusion of WATER through a
  selectively permeable membrane.
• Water wants to DISSOLVE an area of high particle
  concentration.

113
What is osmosis?

• Isotonic Both portions of the solution are of
  the same concentration.
• If two portions of a solution have UNEQUAL
  concentrations, then
• Hypertonic The portion of the solution with the
  higher concentration
• Hypotonic The portion of the solution with the
  lower concentration.

114
What is osmosis?

• If a cell is in a hypertonic solution, then water
  moves OUT of the cell in order to dissolve the
  outside solution, and the cell SHRINKS.
• If a cell is in a hypotonic solution, then water
  moves IN to the cell in order to dissolve the
  solution within the cell, and the cell EXPANDS.

115
What is facilitated diffusion?

• Facilitated diffusion Movement of particles
  from higher concentration to lower
  concentration.BUT
• For particles that are too large to pass through
  the lipid bilayer.particles instead pass through
  protein channels
• Since this is still a type of diffusion, it
  requires NO energy (passive transport).

116
What is active transport?

• Active transport movement of particles from an
  area of lower concentration to an area of higher
  concentration
• Uses protein channelspumps
• Requires ENERGY!!

117
What is endocytosis?

• Endocytosis the process of taking materials
  (usually food) into a cell through pockets within
  the cell membrane.
• Phagocytosis cell eatinglarge food molecules
• Pinocytosis cell drinkingliquids
• Exocytosis the release of material (usually
  waste) from a cell

118
What is exocytosis?

• Exocytosis the release of material (usually
  waste) from a cell

119
(8.1) What is photosynthesis?

• Autotrophs organisms that make their own food
• Heterotrophs cant make their own food, so they
  EAT it
• ATP (adenosine triphosphate) chemical compound
  used to release ENERGY

120
What is photosynthesis?

• ATP (adenosine triphosphate) chemical compound
  used to release ENERGY
• ADP (adenosine diphosphate) uncharged battery
  compound within organisms used to store energy
• When an organism wants to STORE energy, it adds a
  third phosphate molecule to ADP to produce ATP,
  which acts as a charged battery
• When an organism wants to RELEASE energy, it
  breaks the chemical bond between the 2nd and 3rd
  phosphate molecule.

121
What is photosynthesis?

• Energy from ATP can be used for
• Active transport (across cell membranes)
• Muscle contraction (movement)
• Protein synthesis (within ribosomes)
• Light production (in fireflies)

122
What is photosynthesis?

• Problems with ATP
• ATP cannot store energy for a long time (it loses
  its charge easily
• SO, energy is stored within ADP and other large
  storage molecules such as GLUCOSE, and the
  energy from glucose is used to add a P to ADP
  to produce ATP only when needed.

123
(8.2) How was photosynthesis discovered?

• Photosynthesis plants use energy from sunlight
  to convert water (H2O) and carbon dioxide (CO2)
  into carbohydrates (glucoseC6H12O6) and a waste
  productoxygen (O2).
• H2O CO2 sunlight ? C6H12O6 O2

124
How was photosynthesis discovered?

• Where does a trees increase in mass come from as
  it grows over the years???
• THREE EXPERIMENTS
• 1) Van Helmont (1600s) most of a plants mass
  as it grows comes from WATER
• 2) Priestley (1700s) plants release OXYGEN when
  they grow (candle expt.)

125
How was photosynthesis discovered?

• 3) Ingenhousz (late 1700s) in order to produce
  oxygen, a plant needs LIGHT
• (He just repeated Priestleys expt., but ran one
  test in the dark and one in sunlight)
• 6CO2 6H2O ----light---gt C6H12O6 6O2

126
What else do plants need to undergo
photosynthesis?

• Plants need carbon dioxide and water, but they
  ALSO need a molecule called CHLOROPHYLL (housed
  in chloroplasts) to capture energy within
  sunlight
• Sunlight is not whiteits actually a mix of
  violet, blue, green, yellow, orange, red

127
What else do plants need to undergo
photosynthesis?

• Chlorophyll ABSORBS energy from sunlight.
• Two types
• Chlorophyll b absorbs violet and blue light
• Chlorophyll a absorbs yellow, orange, red
  light
• (the only color of sunlight that is NOT absorbed
  is green.green is therefore REFLECTED, and that
  is why most plants appear to be green!!!)

128
What else do plants need to undergo
photosynthesis?

• The energy that is absorbed from the sunlight is
  used to drive the chemical reaction that breaks
  down CO2 and H2O to make the sugars and oxygen
  within photosynthesis!

129
(8.3) What makes up a chloroplast?

• (Photosynthesis takes place inside chloroplasts)
• Thylakoids sac-like membranes arranged in
  stacks called GRANA
• Light-dependent reactions take place here.
• Stroma region outside the thylakoid membranes
• Light-independent (dark) reactions take place
  here.
• Also called Calvin Cycle

130
What is photosynthesis?

• Photosynthesis consists of TWO major chemical
  reactions
• Light-dependent reactions
• Need sunlight
• Use H2O to produce ATP, NADPH, and O2
• Calvin Cycle
• Use CO2 and ATP/NADPH to produce sugars
• (and send ADP/NADP back to light-dependent
  reactions)

131
What happens within the Calvin Cycle?

• During the Calvin Cycle, ATP and NADPH that are
  created during the light-dependent reactions are
  used to fuel the production of glucose.

132
What happens within the Calvin Cycle?

• Overall, 6 CO2 molecules are used to make a
  single 6-carbon sugar (glucose)!!!

133
What factors affect photosynthesis?

• Factors that affect photosynthesis include
• 1) Droughtplants need H2O in light-dependent
  reactions!!
• 2) Temperaturephotosynthesis works best between
  0-35o Celsius.
• 3) Light Intensityshade/sun factors into the
  speed of photosynthesis.

134
What is cellular respiration?

• Cellular respiration process that releases
  energy by breaking down glucose (and other food
  molecules) in the presence of oxygen
• 6O2 C6H12O6 ? 6CO2 6H2O energy

135
What is cellular respiration?

• Cellular respiration takes place in the
  MITOCHONDRIA!!!
• 3 major stages of cellular respiration
• 1) Glycolysis
• 2) Krebs Cycle (a.k.a. Citric Acid Cycle)
• 3) Electron Transport Chain (ETC)
• ALL THREE STAGES PRODUCE ATP!!!

136
What is glycolysis?

• Glycolysis first step in releasing the energy
  of glucose
• 1 molecule of glucose is broken down into two
  molecules of pyruvic acidsimply broken in half
• Uses 2 ATP molecules to break down glucose, but 4
  ATPs are produced!
• A net gain of 2 ATPs!!

137
What is glycolysis?

• AFTER glycolysis, two processes may occur
• If oxygen IS present, the Krebs Cycle occurs.
• If oxygen IS NOT present, fermentation occurs.

138
What is fermentation?

• Fermentation the release of energy from food
  molecules by producing ATP in the absence of
  oxygen (anaerobic environment)
• Very inefficient when compared to aerobic
  processes
• 1) Alcoholic fermentation (in yeast)
• 2) Lactic acid fermentation (in humans)

139
What is fermentation?

• Lactic acid fermentation occurs within muscle
  cells of animals when insufficient oxygen is
  available
• Lactic acid causes burning muscles after
  running or working out!!!

140
(9.2) What happens after glycolysis (when there
is oxygen)?

• Rememberafter glycolysis, if there is no oxygen,
  then fermentation occurs.
• If there IS oxygen, then the Krebs Cycle occurs.
• At the end of glycolysis, 90 of the energy
  within glucose is still availablewe need to
  extract it!!!

141
What happens after glycolysis (when there is
oxygen)?

• Aerobic with oxygen
• Anaerobic without oxygen
• If there IS oxygen, then the Krebs Cycle occurs.
• Krebs Cycle (citric acid cycle)pyruvic acid is
  broken down into carbon dioxide, and energy is
  released.

142
What is the ETC?

• ETC uses batteries produced during Krebs Cycle
  to produce more ATP.

143
How much ATP is produced during cellular
respiration?

• For each glucose molecule
• Glycolysis 2 ATPs are made
• Krebs Cycle/ETC 34 additional ATPs are made
• 36 TOTAL ATPs (with oxygen)
• Only 2 total ATPs (without oxygen)

144
What makes up DNA?

• Ingredients of DNA include
• Nucleotides sugar (deoxyribose), phosphate
  group, nitrogenous base.
• Nucleotides, chained together, form a DNA
  molecule.
• There are 4 n-bases in DNA
• Adenine, Guanine, Cytosine, Thymine (A, G, C, T)

145
What are Chargaffs rules?

• G always matches with C
• A always matches with T

146
What is a double helix?

• Watson and Crick discovered structure of DNA
  molecule
• Double helix
• twisted ladder

147
(12.2) How does DNA replicate?

• Prokaryotes usually have ONE circular DNA
  molecule
• Eukaryotes usually have MULTIPLE elongated DNA
  molecules

148
How does DNA replicate?

• Chromosomes are SO long, they have to be tightly
  wrapped in order to fit into a cells nucleus!
• There is over 1 meter of DNA in each nucleus of
  each human cell!!!!!!!!!!!!!!

149
How does DNA replicate?

• DNA coils in the following way
• 1) DNA wraps around histones (protein spheres) to
  form nucleosomes (bead-like DNA/histone combo)
• 2) Nucleosomes coil/wrap around each other very
  tightly to form a chromosome.

150
How does DNA replicate?

• DNA replication
• 1) DNA splits at multiple locations along the
  strand at replication forks.
• DNA polymerase enzyme unzips double strand.
• (Hydrogen bonds connecting strands are broken.)
• 2) Two strands of double helix completely
  separate.
• 3) New n-bases attach to each original strand
  (A-T and C-G) to form two new complementary
  strands.
• 4) Both new double-stranded molecules twist
  into a double helix.

151
How does DNA replicate?

• Before replication 1 double helix
• After replication 2 double helices
• Each with one original strand and one
  complementary strand!
• (Semi-conservative replication.)

152
(12.3) How does RNA differ from DNA?

• Genes are coded in DNA..but, you must DECODE the
  DNA!!!
• RNA is a molecule that assists in the gene
  decoding process.
• (DNA contains the instructions to make proteins,
  but RNA actually participates in the
  protein-making process.)

153
How does RNA differ from DNA?

• RNA is different from DNA in these ways
• 1) RNAs sugar is ribose, not deoxyribose
• 2) RNA is single-stranded, not double-stranded
• 3) RNA contains Uracil instead of Thymine
• A, C, G, U instead of A, C, G, T

154
What is RNA?

• Three types of RNA
• 1) Messenger RNA (mRNA) messengers from DNA to
  the rest of the cell (specifically ribosomes)
• 2) Transfer RNA (tRNA) assists in the assembly
  of proteins during translation
• 3) Ribosomal RNA (rRNA) ingredient of ribosomes

155
What is transcription?

• Transcription the process of copying nucleotide
  sequences from DNA into a complementary sequence
  in RNA
• Process
• 1) RNA polymerase (enzyme) unzips
  double-stranded DNA in nucleus.
• Bind at PROMOTERS (start signal areas of DNA)

156
What is transcription?

• 2) One strand of DNA (template strand) is used to
  assemble a complementary strand of RNA.
• T ? A, A ? U, G ? C, C ? G
• 3) RNA is sent from the nucleus to the ribosome
  for TRANSLATION

157
How is RNA edited?

• Introns DNA sequences that are useless in
  protein production
• Exons DNA sequences that code for
  proteins.useful
• To finish transcription, introns are cut out and
  the remaining exons are glued back together so
  100 of the new RNA molecule is useful.

158
How does one read the genetic code?

• Codon three nucleotides that specify a single
  amino acid
• Amino acid ingredients of proteins
• RNA UCGCACGGU
• Three codons are UCG CAC GGU
• UCG ? Serine (amino acid)
• CAC ? Histidine
• GGU ? Glycine

159
What is translation?

• Translation process of decoding an mRNA message
  into an amino acid chain to produce a PROTEIN.
  (see Fig. 11.9 on p. 294)
• Process
• 1) mRNA attaches to a ribosome.
• 2) Each codon on mRNA is read and the proper
  amino acid is attached to a chain by tRNA.
• 3) Protein chain is complete when a STOP codon
  is read.

160
(12.4) What are mutations?

• Mutations changes in genetic material
• Caused by mistakes in copying DNA
• Inserting an incorrect n-base
• Skipping an n-base

161
What are mutations?

• Gene mutations occur in a single gene
• Chromosomal mutations occur and produce changes
  in a whole chromosome

162
What are mutations?

• Point mutations change one or a few n-bases
  occur at a single point in the DNA sequence

163
What are mutations?

• Frameshift mutations addition or deletion of an
  n-base that shifts the reading frame of the gene
• More dangerous than point mutations b/c they can
  alter the ENTIRE amino acid sequence instead of
  just one amino acidALL codons can be affected!!!

164
What are mutations?

• Chromosomal mutations changes in the number or
  structure of entire chromosomes
• May delete entire genes, change location of
  genes, or make extra copies of genes

165
Why are mutations important?

• Most mutations are NEUTRALthey have no effect on
  protein production and gene function.
• Harmful mutations cause genetic disease, cancers,
  etc. (Ch. 14)
• Beneficial mutations increase genetic variability
  in organisms and allow species to evolve more
  quickly by adapting to the environment.

166
(12.5) How and when are genes expressed?

• Not all genes in a cell are expressed all the
  time.
• GENE REGULATION controls when genes should be
  turned on for transcription/translation and
  when they should be turned off

167
How are genes regulated?

• Genes usually contain specific regions for
  regulation
• Promoter (RNA polymerase binds to start
  transcription)
• Operator (Repressor can bind to this region to
  turn gene off if repressor is NOT bound to
  operator, gene is on)
• Coding sequence (the actual n-base code for amino
  acid/protein production)
• Stop sequence

168
How are genes regulated?

• Gene regulation is ALWAYS important, but is
  extremely important during embryonic growth.
• Certain genes need to be turned on/off at
  specific times in order for an organism to grow
  and differentiate correctly.
• DIFFERENTIATION process that occurs that causes
  cells to become specialized in structure and
  functionstem cells turn into nerve cells, muscle
  cells, etc.

169
How are genes regulated?

• HOX genes a series of genes that controls
  growth/differentiation of an embryo
• Mutations in HOX genes lead to severe
  abnormalites
• A certain HOX gene mutation in fruit fly embryos
  led to the replacement of antennae with legs!!!

170
(10.1) How big can a cell grow?

• The larger a cell is, the more demands there are
  on its DNA
• Since DNA does not grow with the cell, there is
  only so much to go around!!
• The larger a cell is, the harder it is to
  transport sufficient nutrients and wastes across
  its cell membrane.
• THEREFORE, cells must DIVIDE to remain SMALL in
  size.

171
What is surface area to volume ratio?

• Sides of a cubic cell 1cm
• Surface area 1cm x 1cm x 6 6cm2
• Volume 1cm x 1cm x 1cm 1cm3
• 6 to 1 ratio.a lot of area for transport!
• Sides of a cubic cell 3cm
• Surface area 3cm x 3cm x 6 54cm2
• Volume 3cm x 3cm x 3cm 27cm3
• 2 to 1 ratio.NOT a lot of area for transport!

172
What is the cell cycle?

• Interphase period of cell growth and copying
  (DNA replication)
• Mitosis period of cell division
• At the end of the cycle, one mother cell will
  have split into two identical daughter cells!!!

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What is the cell cycle?

• Steps of the cell cycle
• 1) Interphase (G1, S, G2) period of cell
  growth
• chromosomes (which hold DNA) are replicated
• sister chromatids two copies chromosomes
• Centromeres area where sister chromatids are
  attached

176
What is the cell cycle?

• 2) Cell division mitosis AND cytokinesis

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What is the cell cycle?

• Steps of mitosis (cell division)
• 1) Prophase
• Chromosomes thicken and become visible
• Centrioles separate to two opposite sides of the
  nucleus
• Spindle fibers form at centrioles
• Nucleus dissolves

179
Why do cells need to divide?

• Cells need to divide, because if they get too
  big
• The nucleus cannot control the entire large cell.
• The cell membrane cannot bring in enough
  materials to keep the entire large cell alive.
• SOCELLS NEED TO REMAIN SMALL IN ORDER TO REMAIN
  MANAGEABLE!!

180
What is the cell cycle?

• Interphase period of cell growth and copying
  (DNA replication)
• Mitosis period of cell division
• At the end of the cycle, one mother cell will
  have split into two identical daughter cells!!!

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What is the cell cycle?

• 2) Metaphase
• Chromosomes line up in the middle of the cell
• Centromere of each chromosome is attached to
  spindle fibers
• The centromere is at the middle of the X that
  connects each doubled chromosome.
• Each of the 2 copies of the doubled chromosome is
  called a sister chromatid.

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What is the cell cycle?

• 3) Anaphase
• Centromeres (that join sister chromatids) split
• sister chromatids separate and move to opposite
  sides of the cell (pulled by spindle fibers)
• Spindle fiber fishing line
• Centriole fishing reel

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What is the cell cycle?

• 4) Telophase
• Chromosomes tangle at opposite ends of cell
• Spindle fibers dissolve
• Nuclear membrane re-forms

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What is the cell cycle?

• 5) Cytokinesis
• Cytoplasm divides to create two separate
  daughter cells with individual
  nucleus/organelles
• Animal cells pinching
• Plant cells cell plate forms (rigid)

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(11.4) What is meiosis?

• Meiosis process of reduction division in which
  the number of chromosomes is cut in half.

196
What is meiosis?

• Humans have 46 chromosomes, 23 from the father
  and 23 from the mother. These chromosomes are
  numbered 1-23 and are arranged in pairs.
• Each pair are called HOMOLOGOUS CHROMOSOMES.
• They code for the same information, but are just
  different versions.paternal and maternal!!!

197
What is meiosis?

• Human BODY cells always have 46 chromosomes (23
  pairs of homologous chromosomes), and are
  therefore called DIPLOID cells.
• Diploid 2 copies or sets

198
What is meiosis?

• But, human SEX cells (gametes) only have ONE
  pair, or set, of chromosomes, and are called
  HAPLOID cells.
• Haploid 1 pair or set
• MEIOSIS Haploid sex cells are produced from
  diploid cells!

199
What is meiosis?

• Phases of meiosis
• 1) Interphase growth, DNA replication
• 2) Meiosis I VERY similar to mitosis
• A) Prophase I each chromosome pairs with its
  homologous chromosomeTETRAD, and CROSSING-OVER
  occurs, where alleles are exchanged between the
  homologous chromosomes.
• B) Metaphase I
• C) Anaphase I spindle fibers pull homologous
  chromosomes towards opposite sides of cell
• D) Telophase I/Cytokinesis

200
What is meiosis?

• (At the end of Meiosis I, there are two haploid
  cells formed from one diploid cell.)
• 3) Meiosis II
• Prophase II, Metaphase II, Anaphase II, Telophase
  II, and Cytokinesis all happen just like mitosis.
• (At the end of Meiosis II, there are four haploid
  cells formed from two haploid cells.)

201
What is meiosis?

• Male gametes sperm/pollen
• 1 diploid cell makes 4 haploid gametes
• Female gametes eggs
• 1 diploid cell makes 1 LARGE haploid gamete and 3
  useless polar bodies
• This is due to uneven cell divisions during
  meiosis within females!

202
What is genetics?

• Genetics the study of heredity
• Heredity the passing of characteristics from one
  generation to the next

203
How were genetic principles discovered?

• Gregor Mendel Austrian monk that discovered
  most basic genetic principles
• In his experiments, Mendel cross-pollinated
  different pea plants on his own.

204
How were genetic principles discovered?

• Mendel had true-breeding pea plants in his
  garden.
• True-breeding plants if they were allowed to
  self-pollinate, their offspring would be
  IDENTICAL to themselves
• Mendel discovered several important
  characteristics of genetics

205
How were genetic principles discovered?

• 1) DOMINANCE
• 7 traits (characteristics) were studied
• Parents with different variations of each trait
  (P) were crossed to form hybrid offspring (F1)
• Trait Seed Shape
• P (round) x P (wrinkled)
• F1 was round
• ROUND was dominant over WRINKLED

206
How were genetic principles discovered?

• Conclusion 1 Each trait was passed from one
  generation to the next (through chemical factors
  called GENES).
• Conclusion 2 There are usually TWO forms of
  each gene, and each of these forms is called an
  ALLELE.
• Conclusion 3 Some alleles are DOMINANT and
  some are RECESSIVE.

207
How were genetic principles discovered?

• 2) SEGREGATION
• What happened to the recessive alleledid it
  disappear? NO!!!
• Example
• Cross P (tall) with P (short)
• tall is dominant, so F1 plants are all tall
• BUT, then cross an F1 with another F1 and get 3
  tall plants and one short plantthe recessive
  allele did NOT disappear!

208
How were genetic principles discovered?

• Segregation the two different alleles for each
  gene SEPARATE from each other during formation of
  GAMETES (sex cells).

209
(11.2) How can we predict the outcomes of genetic
crosses?

• Punnett square a diagram that displays results
  from a genetic cross
• Assume that each genetic trait has two alleles
• Dominant allele capital letter (T)
• Recessive allele lowercase letter (t)
• TT Homozygous dominant
• tt Homozygous recessive
• Tt Heterozygous

210
How can we predict the outcomes of genetic
crosses?

• Phenotype physical characteristics
• the plant is tall
• Genotype genetic makeup
• the plant is homozygous dominant, TT

211
(11.3) What is independent assortment?

• After Mendel figured out that one allele was
  DOMINANT over another allele, and that these two
  alleles SEGREGATE independently into gametes, he
  had another question.
• Does the segregation of one pair of alleles
  affect the segregation of another pair of
  alleles?
• Does the gene determining seed shape related to
  the gene determining seed color?

212
What is independent assortment