BIOLOGY OVERVIEW

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BIOLOGY OVERVIEW
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Organic Compounds

• PROTEINS
• Subunits- Amino Acids
• Classes
• Structural Proteins
• Hormones
• Transport Proteins
• Antibodies
• Enzymes

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Organic Compounds

• CARBOHYDRATES
• Subunits-Monosaccharides such as glucose
• Classes
• Energy storage
• Structure in plants

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Organic Compounds

• LIPIDS
• Subunits-Often contain glycerol and fatty acids
• Classes
• Energy storage
• Insulation/ Waterproofing
• Hormones

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ORGANIC COMPOUNDS

• NUCLEIC ACIDS
• Subunits- Sugar (ribose or deoxyribose),
  phosphate, nitrogenous base.
• Examples
• DNA
• RNA
• ATP

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Cell Theory

• All living things are composed of cells.
• Cells are the basic unit of structure and
  function of living things.
• All cells arise from preexisting cells.

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Cell Comparison

• PROKARYOTE
• No nucleus
• no membrane bound organelles
• include bacteria (and archaebacteria)

• EUKARYOTE
• Contain nucleus and organelles
• include protists, fungi, plants, animals

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Cell is a Factory 1

• Protein making (ex antibody)
• Code is carried on DNA
• Transcription Message is coded onto mRNA.
• mRNA carries the message to the ribosome.
• Translation Protein is assembled by tRNA
  carrying amino acids to ribosome.

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Cell is a Factory II

• Protein is carried through the endoplasmic
  reticulum. Here, as on a conveyor belt, some
  modifications may be made.
• Protein is transferred to Golgi Apparatus for
  final touches and packaging.
• Protein is either exported from cell or used
  within the cell.

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Cellular Transport How materials enter or leave
cells
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Photosynthesis/ Respiration

• Photosynthesis
• 6 CO2 12 H20 ---gt C6H12O6 6 H206O2
• Cellular Respiration
• C6H12O6 6 H206O2 -----gt 6 CO2 12 H20

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Cell Division

• Mitosis
• Nuclear Division
• Results in two identical nuclei
• Most cells except sex cells.

• Meiosis
• 2 Nuclear Divisions
• Results in 4 different nuclei
• Sex cells

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(Before mitosis)
Tg
Tg
tG
tG
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Punnett Squares

• Results of Meiosis On Outside

Tg
Tg
tG
TtGg
TtGg
TtGg
tG
TtGg

• Offspring Represented by Cross and Shown
  inside

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Dihybrid Cross RrYy x RrYy
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DNA

• Only 4 bases carry the code of life for every
  living thing.
• Adenine (A) -Thymine (T)
• Cytosine (C) -Guanine (G)
• Mistakes in the code are rare. Mistakes may
  result in disorders but are also the basis for
  beneficial adaptations.
• Ex webbed feet in ducks.

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RNA

• EXPRESSED DNA is first transcribed to RNA.
• To see what DNA is functioning in an individual,
  look at the transcribed RNA.

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Evolution by Natural Selection

• There is variation among offspring.
• Not all offspring will survive.
• Those offspring whose traits best fit the
  environment are most likely to survive.
• Those who survive and reproduce pass their traits
  on to the next generation.

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Hardy-Weinburg EquilibriumA Hypothetical
Population with No Evolution

• Large population size.
• Mating is random.
• No mutation
• No immigration of genes
• No selection occurs.

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Agents of Evolutionary Change

• (Opposite of Previous Slide)
• Genetic drift-random change in gene frequency
  because of small populations.
• Non-random mating
• Mutation
• Gene flow- genes are exchanged by migration
• Selection Occurs

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Radioactive Dating

• The constant rate of decay of isotopes can be
  used to date fossils.
• An ancient 6-mg fern sample is found to have
  0.065 mg of C-14. This sample originally
  contained 2.0 mg of C-14. The half life of C-14
  is 5730 years. What is the approximate age of
  the sample?

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Biological Diversity

• 6 Kingdoms of Life Include
• Archaebacteria- (prokaryotes) ancient bacteria,
  i.e. thermophiles (live in extreme temperatures),
  halophiles (salt lovers), and methanogens
  (methane producing bacteria)
• Eubacteria- (prokaryotes) true bacteria, i.e.
  those that cause disease, and are used for
  fermentation, etc.
• Protists- unicellular Amoeba, Paramecium, and
  multicellular seaweed
• Fungi- unicellular and multicellular decomposers
  such as mushrooms, mold and yeast
• Plants- autotrophic, multicellular
• Animals- heterotrophic, multicellular

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Connections to Bacteria

• Genetic Engineering of bacteria for industrial
  purposes and in pharmaceuticals
• Bioremediation
• Exponential Growth
• Their role as decomposers in the ecosystem
• Nitrogen fixing bacteria in the roots of legumes,
  and denitrifying bacteria to return nitrogen to
  the atmosphere

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Connections to Protists

• Use of seaweed
• Diatoms create diatomaceous earth (SiO2
  shells/tests)
• Dinoflagellates have two flagella and can cause a
  red tide, as well as shellfish contamination
• Pfisteria causes fish kills
• Algal blooms are caused by nutrient run-off into
  lakes and ponds (eutrophication). The algae
  deplete the oxygen supplies in the pond as they
  respire and when they die, the decomposing
  bacteria also deplete the oxygen supply for fish,
  etc.
• Role of protists in disease
• Amoebic dysentary Amoeba
• Malaria- Plasmodium
• African Sleeping Sickness- Trypanosoma

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Connections to Fungi

• Role of fungi as decomposers and recyclers
• Fungi (yeast) and bacteria are used in alcoholic
  (making beer, wine, and bread rise) and lactic
  acid fermentation (making yogurt and cheese).
• Alcoholic is shown below

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Connections to Plants

• Plants capture the suns energy and create an
  organic energy source called glucose
  (photosynthesis)
• Plants release oxygen to the atmosphere and
  return water to the atmosphere through
  transpiration (Larger leaf surfaces, more
  stomatesholes in leaf surface).
• Reproductive mechanisms-

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Connections to AnimalsSee Animal Comparative
Chart

• Basic themes exist between sciences
• Transport- Circulatory
• Response to Stimuli- Nervous
• Energy Use- Digestive
• Waste Disposal- Excretory
• Use of Gases- Respiratory

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Human Body Connections

• Thermoregulation- See handout

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Respiratory System

• Gas transport when oxygen binds to hemoglobin
  (iron containing molecule)
• Surface area of alveoli is great (tiny air sacs
  in the lungs) for diffusion of gases from a
  higher concentration to an area of lower
  concentration.

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Action Potential

• This is how impulses are conducted throughout
  neurons, muscle cells, heart cells, etc.
• An excess of sodium ions is on the outside of the
  neuron at rest
• An excess of potassium ions is on the inside of
  the neuron at rest.
• At rest the charge inside of the neuron is -70
  mvolts.
• When stimulated, the positively charged sodium
  ions rush in, depolarizing the inside of the
  cell.
• Then the positively charged potassium ions leave
  the cell, repolarizing the inside of the cell.
• Finally, sodium and potassium are actively pumped
  to their original spots to establish resting
  potential again. This is called the refractory
  period.

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Summary of Action Potential
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Nervous System

• Action potentials are used to transmit impulses
  down an neuron
• Neurons are insulated with a fatty covering
  called myelin that serves as a good conductor.
• When the impulse reaches the end of a neuron,
  chemicals called neurotransmitters are released,
  and they travel to the next neuron to generate
  the next action potential.
• Enzymes break the neurotransmitter down so they
  can be recycled for the next impulse.
• Neurotransmitters include
• Acetylcholine- transmits impulses to muscle cells
  to make them contract
• Dopamine, epinephrine, and serotonin have various
  roles in transmitting pleasure impulses, blocking
  pain impulses, etc.
• GABA (gamma aminobutyric acid) is an inhibitor
  neurotransmitter

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Circulatory System

• Electrical activity of hearts pacemaker
• Atria depolarize, contract, and then repolarize
• Ventricles depolarize, contract, and then
  repolarize
• Blood pressure is measured as mm Hg using a
  sphygmomanometer as the arterial blood pushes
  against the wall of the artery.
• Systolic pressure (the top number) is when the
  ventricles contract and the blood rushes out of
  the heart through the arteries.
• Diastolic pressure (the bottom number) is when
  the ventricles are relaxed and not pumping and
  the arterial blood is exerting the least amount
  of pressure on the artery wall.

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Digestive System

• Mechanical and chemical digestion of food occurs
  as food moves from the mouth to the stomach.
• Enzymes are used to break food down into
  monomers.
• Monomers move through the walls of the small
  intestine into the bloodstream, through
  fingerlike projections called villi.
• Monomers, like glucose, amino acids, fatty acids,
  and nucleotides move using the principles of
  diffusion (higher concentration to lower
  concentration).

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Muscular

• Sliding filament theory of muscle contraction
• As the action potential runs along the cell
  membrane of the muscle cell, calcium ions are
  released from a storage area and they bind to
  troponin on the actin to expose the binding sites
  so myosin can attach.

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Immune

• Cell to cell recognition is accomplished by
  antigens and antibodies.
• Non-self antigens are considered foreign proteins
  not recognized by the body, while self antigens
  are present on the surfaces of our own cells.
• Antibodies are produced in response to foreign
  antigens. They help fight the antigens by
  clumping them together to make them more
  appetizing to white blood cells.
• Monoclonal antibodies are used in cancer
  treatments as well as wildlife management. For
  example, hatchery fish can be identified vs. the
  same fish that is found in the wild.

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Endocrine

• Operates according to negative feedback
  principles.
• Negative feedback loops drive the endocrine
  system

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Ecology Connection

• Population Growth Curves

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Predator Prey Growth Curves
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Ecological Succession

• Primary Succession

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Ecological Succession

• Secondary Succession

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Energy Transfer

• Food chains represent energy transfers in
  ecosystems.
• The sun provides the energy and it is captured by
  the producers through photosynthesis.
• The consumers maintain only about 10 of the
  energy contained at the trophic levels below
  them, as 90 of the energy is lost as heat.

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Cycling of Nutrients

• Carbon Cycle- We focus on the processes of
  photosynthesis, respiration and decomposition, as
  well as fossil fuel production.

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Nitrogen cycle

• We focus on Nitrogen fixation- nitrogen gas to
  ammonium by nitrogen fixing bacteria in the roots
  of legumes
• Ammonium to nitrites and nitrates by nitrifying
  bacteria in the soil.
• Ammonium or nitrates taken up by plants to make
  DNA, proteins, and ATP.
• Animals eat plants, and excrete nitrogen in
  urine, etc.
• Denitrifying bacteria convert nitrogen in soil
  back to nitrogen gas.

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Water Cycle

• We focus on transpiration of water through plant
  leaves (larger surface area more stomates so
  more water exits)
• Plants use water for photosynthesis
• Animals release water through respiration (exits
  as sweat and urine)

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Biological Magnification of Pesticides
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Human Impact

• Global climate change- increase of carbon dioxide
  by burning fossil fuels and deforestation, rising
  sea levels could decrease agricultural output
• Ozone depletion- UV radiation damages the DNA of
  plants and animals
• Acid rain- plants and animals die due to the
  presence of sulfuric and nitric acids
• Desertification- loss of habitat, agricultural
  output decreases
• Deforestation- loss of fertile soil due to
  nutrient depletion and overgrazing
• Pollution- DDT (shown earlier), Algal blooms
  (Described under Protists)
• Reduction in species diversity due to the above
  factors reduces medicines, foods, or industrial
  products