Introductory Questions

1
Introductory Questions 1

• Name the seven main properties of life. (Pg. 3)
• Which of the hierarchial levels of biology is the
  lowest in regard to carrying on and sustaining
  all life activities and is the fundamental unit
  of life? (pg 5)

2
Introductory Questions 1

• 3. In your own words briefly describe what
  emergent properties are.
• 4. How is negative feedback different from
  positive feedback? (pg. 11) What do these
  mechanisms do for a living thing?
• 5. Name the three domains of life. Which domain
  includes four out of the six kingdoms of life?
• 6. Why is natural selection considered the
  mechanism for evolutionary adaptations to
  occur?
• 7. How is a hypothesis different from a theory?
• 8. From all the themes presented on pg. 27,
  which theme(s) is/are the most challenging for
  you to learn? Which theme is the unifying theme
  for all eleven presented?

3
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5
How Would You Define Life?

• Living vs. Non-Living
• Is a Virus a living thing? Why or why not?

6
The Seven Properties of Life Pg. 3
7
Properties of Life

• Complex organization (hierarchical)
• Reproduction
• Growth and Development
• Utilize Energy
• Respond to the Environment
• Homeostasis
• Adapt

8
Hierarchical Levels of Organization
(reductionism) pg. 4-5

• Atom
• Molecules
• Macromolecules
• Organelles
• Cells
• Tissue
• Organs
• Organ Systems
• Organism
• Population
• Community
• Ecosystem
• Biomes
• Biosphere
• http//micro.magnet.fsu.edu/primer/java/scienceopt
  icsu/powersof10/ (Powers of ten video)

9

• A web of interactions in a rain forest ecosystem

Figure 1.7A
10

• Chemical nutrients are Recycled within an
  Ecosystem (pg. 6)

Sun

• Energy flows in and out constantly

Inflowoflightenergy
Lossofheatenergy
Air
Chemicalenergy
Cyclingofchemicalnutrients
Organisms
Soil
Figure 1.7C
ECOSYSTEM
11
Tree of Life
12

• Most classification schemes group organisms into
  three domains (pg. 13-14)

• Domain Bacteria

• Domain Archaea

Figure 1.4A, B
13

• Domain Eukarya

Figure 1.4C-F
14
Six Kingdoms of Life

• Archaebacteria (Ch 27)
• Eubacteria (Ch 27)
• Protista (Ch 28)
• Fungi (CH 31)
• Plantae (Ch 29-30)
• Animalia (Ch 32-34)

15
Online quiz scoring

• 75-100 2pts
• 50-74 1pt
• Below 50 0pts
• FIRST ATTEMPT IS THE ONE THAT GETS RECORDED

16
REMINDER!

• PLEASE PUT CHAIRS ON TABLES AT THE END OF CLASS
• THANK YOU!

17
Chemical Basis of Life Unit 1

• Chapter 1 Themes in the Study of Life
• Chapter 2 Chemical Context of Life
• Chapter 3
• Properties of Water
• Chapter 4
• Carbon Functional Groups
• Chapter 5
• Polymers Macromolecules
• Science Animations
• http//science.nhmccd.edu/biol/animatio.htm

18
Cycles of Life Biological Concepts (video
questions)

• How is non-living matter distinguished from
  living matter? What factors do we need to
  consider?
• How does energy flow from the sun to living
  organisms? (Dr. Saltman)
• What concepts did Dr. Christopher Wills discuss
  in the video?
• What are the steps to the scientific method?
• Name the animal that was studied by analyzing its
  bones in order to trace its evolution.
• Write the Title for each of the three segments
  and list 5 key concepts (statements) from the
  segment. (typically I will pause the video and
  help you pinpoint the most important things to
  write)

19
Introductory Question 2

• Name two differences between a eukaryotic cell
  and a prokaryotic cell.
• How does asexual and sexual reproduction differ?
• Name the six kingdoms mentioned in your text.
• How does cellular respiration differ from
  photosynthesis? Write the chemical equations for
  each process.
• Name the key steps involved in the scientific
  method.
• How does inductive reasoning differ from
  deductive reasoning?
• Why must you have both an experimental group as
  well as a control group when conducting an expt.?

20
Classifying Living Organisms

• 1.8 million species have been identified
• Total species count range from 10million-200
  million
• 99 of all species present on Earth have gone
  extinct
• Naming system is needed.
• Taxonomy system
• Binomial Nomenclature (using genus species
  names)
• Developed by Carolus Linnaeus
• Levels include K-P-C-O-F-G-S

21
Prokaryotic vs. Eukaryotic Cells
22
Eukaryotic vs. Prokaryotic Cells-(pg. 8)
23
Reproduction

• Asexual -egg sperm do not fuse (no
  fertilization)
• -genes do not recombine
• -clones are formed
• -minimal variation (exception mutations)
• Sexual -fertilization does occur
• -genes interact and recombine
• -genetic variation occurs
• -provides raw materials for evolution
• adaptations

24
Reproduction
25
Example of Negative Positive Feedback (pg. 11)

• Thermal regulations
• digestion

• Platelets
• Lactation
• contractions

26
Evolution explains the unity and diversity of
life (pgs. 15-18)

• Charles Darwin is a central figure in biology
• He synthesized the theory of evolution by natural
  selection
• A theory in science is a comprehensive idea with
  broad explanatory power
• Evolution is the core theme of biology

Figure 1.6A
27

• The theory of natural selection explains the main
  mechanism whereby all species of organisms
  change, or evolve

(1) Population with varied inherited traits
(2) Elimination of individuals with certain traits
(3) Reproduction of survivors
Figure 1.6B
28
Paleontology
29

• DNA is made of chemical units called nucleotides

• Each species has its own nucleotide sequence

Figure 1.5B
30
DNA Technology
31
Unifying Themes in Biology

• Evolution biologys core theme differential
  reproductive success
• Unity Diversity three domains
• The Cell all organisms basic structure
• Heritable Information DNA
• Structure Function form and function
• Energy Life sunlight producers--consumers
• Emergent Properties Biological Systems
• Environmental Interaction organisms are open
  systems
• Regulation feedback mechanisms (homeostasis)
• Unity Diversity universal genetic code
  
• Scientific Inquiry observation testing
  repeatability (Pgs. 15-20)
• Science, Technology Society functions of our
  world

32
Scientific Method

• Inductive vs. Deductive reasoning
• Observations
• Ask Questions
• Form a Hypothesis (make predictions)
• Test these predictions w/Experimentation
• Interpret Results
• Draw conclusions (accept or reject hypothesis)
• Repeat Experiment to increase validity

33

• In hypothesis-driven science, scientists use the
  scientific method

• They propose a hypothesis
• They make deductions leading to predictions
• They then test the hypothesis by seeing if the
  predictions come true

34
Lab 1- Quantifying Vitamin C

• Using the internet research the following
• What is Vitamin C? (composition)
• What is the significance (importance) of Vitamin
  C? Why is it important to us?
• What does it do physiologically in the body?
• Where can we find Vitamin C?
• How can we quantify the amount of vitamin C in
  food? Identify some reasonable methods that can
  be used.
• Design an experiment that would allow you to
  accurately quantify the amount of vitamin C in
  certain foods and factors that change its
  function.
• Make a hypothesis for your experiment.

35
Vitamin C (Ascorbic acid)

• Water soluble
• Easily oxidized (loses electrons or Hs)
• Plays a key role for producing collagen and
  norepinephrine in the body.
• Body cannot produce it, it must be consumed
• Deficiencies cause scurvy, hemorrhage in the
  gums, joint pain, exhaustion, etc.
• Optimum daily intake is debatable (30mg to 2g per
  day)
• Excess can damage kidneys excreted in urine
• Sources Fruits, vegetables, and organ meats
  (liver)
• Exposure to air, soaked or boiled in water
  decreases its activity

36
Topics that can be explored

• Factors that are important in decomposition of
  ascorbic acid ie. Heat
• Determine the effects of different food
  preparation methods on ascorbic content
• Differences in ascorbic acid content in various
  parts of a fruit or vegetable.
• Compare different brands of frozen fruit juices
  for ascorbic acid content.

37
Guidelines/Procedure for Lab 1

• Day 1 Develop standard and determine the amount
  of ascorbic acid in three unknown solutions
• Day 2 (Mon.) Bring in items you would like to
  test and compare. These items can be treated in
  various ways such as steamed, boiled, or soaked
  in water if you wish. Depends on what you want
  to analyze.

38

• Need to compare the unknown solution with a
  known solution of vitamin C Standard Solution
  
• Vitamin C content of the standard solution is
• 500 mg Vit. C
• 1000 ml solution
•  
• Key point You need to know how many drops of
  the standard it takes to neutralize the DCIP from
  blue color to colorless.

39
Calculations

• To determine Vitamin C amount in each juice do
  the following calculation
• ( drops standard soln.)(500mg/1000ml)
• ( drops unknown soln. being tested)( ?
  mg/1000 ml) 
• Calculate for three unknown solutions using the
  equation above.

40

• Key point You need to know how many drops of
  the indicator solution it takes to neutralize the
  known standard solution and determine the volume
  (ml) that the number of drops represents.

41
Scientific Method
Observation

• The main steps of the scientific method

Question
Hypothesis
Prediction
Test does notsupport hypothesis revise
hypothesis or pose new one
Test supports hypothesis make additional
predictions and test them
Test Experiment oradditionalobservation
Figure 1.3A
42
Sampling Error
43

• Case study spider mimicry

Figure 1.3C
Pounce rate ( of trials in which spider jumped
on fly)
Control group(untreated flies)
Experimental group(wing markings masked)
Figure 1.3D
44
Experiment

• Tests a hypothesis
• Control Experimental groups present
• Only one variable is changed
• Dependent vs. Independent
• -measured value -held constant
• -outcome/result -known quantity
• Typically y x
• Data is collected-quantitative or qualitative
• Must be reliable and valid
• ex. sampling error
• Know your sources of error
• Must repeatable

45

• Experiments designed to test hypotheses must be
  controlled experiments

• Control groups must be tested along with
  experimental groups for the meaning of the
  results to be clear

46

• Another test of the spider mimic hypothesis wing
  transplants

Number of stalk andattack responsesby spiders
Wingmarkings
Wingwaving
Normalspidermimic
Mimic withmimic wing transplant
Mimic withhousefly wing transplant
Housefly withmimic wing transplant
Normalhousefly
Figure 1.3E
Controls
Experimentals
47
BIOLOGY AND EVERYDAY LIFE

• Biology is connected to a great number of
  important issues
• Environmental problems and solutions
• Genetic engineering
• Medicine

Figure 1.8A
48
Theory vs. Law

• Theory Consistent support of a hypothesis from
  many observations or experiments.
• -Relates facts
• -Predicts new facts
• -Suggests new relationships
• -Grows and builds on additional facts
• Law A universally accepted scientific principle
  that yields true predictions over a long period
  of time. Now Theory is often used in place of Law
  because nothing is absolute in science.

49
Laboratory Criteria

• IB requires 40 hours (SL) 60 hours (HL)
• AP has 12 recommended labs
• http//www.sc2000.net/czaremba/aplabs/
• IB Lab Requires a written report
• Group 4 project (Seed Germination)

50
IB Lab Report Grading Rubric(All will
participate)

• Catagories
• Planning A and B
• Data Collection
• Data Analysis
• Data Processing and Presentation
• Conclusion Evaluation
• Manipulative skills
• Personal skills A and B

51
Extra Credit Opportunity (5pts)

• Two Options
• Bring in paper towels or kleenex
• Come in Tuesdays after school and help me with
  some tasks (20 min)

52
Chapter 2

• Structure of the atom
• Isotopes
• Electron orbitals
• Bonding
• Molecular structure

53
Introductory Question 2

• Do the 10 multiple choice questions on pg
  29 and answer the evolution connection question.
  (HW)
• Explain what valence electrons are and why they
  are important.
• Explain how covalent bonds are different from
  ionic bonds. Which one is stronger? How are Van
  der Waal forces different from a hydrogen bond?
• How is a molecular formula different from a
  structural formula?

54
The emergence of biological function starts at
the chemical level

• Everything an organism is and does depends on
  chemistry
• Chemistry is in turn dependent on the arrangement
  of atoms in molecules
• In order to understand the whole, biologists
  study the parts (reductionism)

55
Chemical Context of Life

• Matter (space mass)
• Element vs. Compound vs. molecule
• The Atom http//www.webelements.com
• Atomic number ( of protons)
• Atomic mass number (protons neutrons)
• Isotopes (different of neutrons) radioactive
  isotopes (nuclear decay)
• Energy (ability to do work) energy levels
  (electron states of potential energy)

56
Life requires about 25 chemical elements

• A chemical element is a substance that cannot be
  broken down to other substances by ordinary
  chemical means
• About 25 different chemical elements are
  essential to life

57
When you lack or have too much

• an excess of copper
• leads to hyperactivity
• a lack of lithium leads
• to depression
• a lack of zinc leads to
• impaired growth
• impaired coordination

58

• Goiters are caused by iodine deficiency

Figure 2.2
59
Atoms consist of protons, neutrons, and electrons

• The smallest particle of an element is an atom
• Different elements have different types of atoms
• Protons Neutrons make up the nucleus
• Electrons exist in distinct orbitals usually
  represented as a cloud moving at the speed of
  light (3.00 x 108m/s)
• Only two electrons can exist in a particular
  orbital

60

• Each atom is held together by attractions between
  the positively charged protons and negatively
  charged electrons

• Neutrons are electrically neutral

6
Protons
Nucleus
6
Neutrons
6
Electrons
B. Carbon atom
Figure 2.4B
61

• Atoms of each element are distinguished by a
  specific number of protons

• The number of neutrons may vary
• Variant forms of an element are called isotopes
• Some isotopes are radioactive

Table 2.4
62
Radioactive isotopes can help or harm us

• Radioactive isotopes can be useful tracers for
  studying biological processes
• PET scanners use radioactive isotopes to create
  anatomical images

Figure 2.5B
Figure 2.5A
63
Useful Isotopes used in Research

• Hydrogen 3H (tritium)
• Phosphorus 32P DNA analysis
• Sulfur 35S Proteins
• Carbon 14C Dating fossils
• These are all radioactive and can be useful as
  tracers, labels or tags by detecting their
  presence.

64
Electron arrangement determines the chemical
properties of an atom

• Electrons are arranged in shells
• The outermost shell determines the chemical
  properties of an atom
• In most atoms, a full outer shell holds eight
  electrons

65

• Atoms whose shells are not full tend to interact
  with other atoms and gain, lose, or share
  electrons

Outermost electron shell (can hold 8 electrons)
Electron
First electron shell (can hold 2 electrons)
HYDROGEN (H) Atomic number 1
CARBON (C) Atomic number 6
NITROGEN (N) Atomic number 7
OXYGEN (O) Atomic number 8
Figure 2.6
66
Valence Electrons

• Valence electrons are the ones on the outermost
  shell
• Involved in forming bonds
• More energetic away from the nucleus
• More stable when paired
• Exist in and travel in a particular orbital path.
• Max. of electrons that can occupy each
  level-use the formula 2n2
• Level of electrons
• 1st 2
• 2nd 8
• 3rd 18 (octet still applies)
• 4th 32 (octet still applies)

67
Elements with their Valence Electrons
68
Energy shell levels Return to Ground State
69
Orbital Sharing between two Atoms
70
Orbital Orientation
71
4 types of orbitals (s, p, d,
and f)S 1 P 3 D 5 F
7
72
Orbitals Energy Levels

• Hybridization occurs blending the orbitals to a
  particular geometric shape.
• http//www.mhhe.com/physsci/chemistry/essentialche
  mistry/flash/hybrv18.swf

73
Endorphin and Morphine Similarities
74
Quantifying/Measuring the Number of atoms or
Molecules

• Molecules and atoms are grouped into a packaged
  amount called mole
• A mole quantity 6.022x1023 items
• Molarity number of moles per liter of solution

75
Introductory Question 3

• How is a hydrophobic molecule different from a
  hydrophilic molecule?
• Why are buffers important in biological systems?
• How many more times acidic is a substance with a
  pH 2 vs. a pH 5?
• Briefly explain how oxidation is different
  reduction.
• Define Temperature and what a calorie is.
• Give three unique characteristics of carbon.
• How does a structural isomer differ from a
  geometric isomer? What are enantiomers?
• List the seven functional groups and draw the
  structural formula for each one.

76
Chemical Bonding

• Ionic
• Covalent
• Double covalent
• Nonpolar covalent
• Polar covalent
• Hydrogen
• van der Waals

77
Some Important Biological Ions

• Name Ion charge Found/function
• Ca
• Na
• K
• H
• Fe
• HCO3
• NO3
• NO2
• OH
• Cl
• CO3
• SO4

78
Ionic bonds are attractions between ions of
opposite charge

• When atoms gain or lose electrons, charged atoms
  called ions are created
• An electrical attraction between ions with
  opposite charges results in an ionic bond

Na
Cl
Na
Cl
Na Sodium atom
Cl Chlorine atom
Na Sodium ion
Cl Chloride ion
Figure 2.7A
Sodium chloride (NaCl)
79
Ionic bonding

• High electronegativity differences strips valence
  electrons away from another atom
• Electron are transferred thereby creating ions
  (charged atoms)
• Cation ( ion) anion (- ion)
• Electrostatic forces hold the two ions together
  nothing is physically holding the two together
• Ex Salts (sodium chloride)

80
Ionically Bonded Substance
Sodium and chloride ions bond to form sodium
chloride, common table salt
81
Disassociation of Ionically Bonded Substances
82
Introductory Question 3

• Why are buffers important in biological systems?
• How is a hydrophobic molecule different from a
  hydrophilic molecule?
• What is the difference between a polar and
  non-polar covalent bond? Why is an atoms
  electronegativity important to consider?
• How many more times acidic is a substance with a
  pH 2 vs. a pH 5?
• Briefly explain how oxidation is different
  reduction.
• Name five important properties of water.
• Define Temperature and what a calorie is.
• Give three unique characteristics of carbon.
• How does a structural isomer differ from a
  geometric isomer? What are enantiomers?
• List the seven functional groups and draw the
  structural formula for each one.

83
Covalent Bonding

• Sharing pair of valence electrons
• Number of electrons required to complete an
  atoms valence shell determines how many bonds
  will form
• Ex Hydrogen oxygen bonding in water methane

84
Covalent bonds, the sharing of electrons, join
atoms into molecules

• Some atoms share outer shell electrons with other
  atoms, forming covalent bonds
• Atoms joined together by covalent bonds form
  molecules
• This allows each atom to become more stable by
  fulfilling the octet rules.
• Electrons will spend a certain amount of time on
  each atom to complete the shells

85

• Molecules can be represented in many ways

Table 2.8
86
Structural Formulas
87
Chapter 3

• Properties of Water

88
Polar/Non-polar Covalent bonds

• Depends on the electronegativity differences of
  each atom and their overall molecular structure
• Electronegativity attraction (affinity) for
  electrons
• Ex. F, O, S, N, Br all are highly
  electronegative
• Nonpolar covalent electrons are shared equally
• - Substances are Hydrophobic in nature
• -Ex diatomic H2, CO2,CH4 and O2
• Polar covalent one atom is more electronegative
  than another. Unequal sharing.
• -Substances are Hydrophilic in nature
• Ex H2O, NH3, and CH3OH (methanol)

89

• In a water molecule, oxygen exerts a stronger
  pull on the shared electrons than hydrogen

• This makes the oxygen end of the molecule
  slightly negatively charged
• The hydrogen end of the molecule is slightly
  positively charged
• Water is therefore a polar molecule

()
()
O
H
H
()
()
Figure 2.9
90
Polarity of Water
91
Hydrogen bonds

• Hydrogen atom covalently bonded to one
  electronegative atom is also attracted to another
  electronegative atom (oxygen or nitrogen)
• http//programs.northlandcollege.edu/biology/Biolo
  gy1111/animations/hydrogenbonds.html
• http//www.johnkyrk.com/H2O.html

92
Hydrogen bond with Nitrogen
93
Hydrogen bonds make liquid water cohesive
Surface Tension

• Due to hydrogen bonding, water molecules can move
  from a plants roots to its leaves
• Insects can walk on water due to surface tension
  created by cohesive water molecules

Figure 2.11
94

• A water molecule takes a large amount of energy
  with it when it evaporates

• This leads to evaporative cooling

Figure 2.12
95
Water is a versatile solvent

• Solutes whose charges
• or polarity allow them to
• stick to water molecules
• dissolve in water
• They form aqueous solutions

Na


Na


Cl
Cl





Ions in solution
Salt crystal
Figure 2.14
96

• Like no other common substance, water exists in
  nature in all three physical states

• as a solid
• as a liquid
• as a gas

Figure 2.10B
97
Ice is less dense than liquid water

• Molecules in ice are farther apart than those in
  liquid water due to hydrogen bonding

Hydrogen bond
ICE Hydrogen bonds are stable
LIQUID WATER Hydrogen bonds constantly break and
re-form
Figure 2.13
98

• Ice is therefore less dense than liquid water
• which causes it to float
• Crystalline lattice keeps molecules at a
• distance
• Ponds, lakes, and oceans would eventually
• freeze solid

99
Defining a Calorie

• Used as a unit for measuring energy
• One calorie amt of energy needed to raise 1
  gram water
• 1? C.
• This amount of energy is 4.184 J (specific heat)
• Ethanol has a specific heat of 2.46 J
• Heat of vaporization for water 540 calories

100
Van der Waals interactions

• Weak interactions between molecules or parts of
  molecules that are brought about by localized
  change fluctuations
• Due to the fact that electrons are constantly in
  motion and at any given instant, ever-changing
  hot spots of negative or positive charge may
  develop

101
Properties of Water

• Polar opposite ends, opposite charges
• Cohesion H bonds holding molecules together
• Adhesion H bonds holding molecules to another
  substance
• Capillary action adhesion cohesion
• Surface tension measurement of the difficulty to
  break or stretch the surface of a liquid
• Specific heat amount of heat absorbed or lost to
  change temperature by 1oC
• Heat of vaporization quantity of heat required
• to convert 1g from liquid to gas states
• Density solid is less dense than its liquid
  form
• Dissolving ionic molecules http//www.mhhe.com/ph
  yssci/chemistry/essentialchemistry/flash/molvie1.s
  wf

102
Depicting/Illustrating Molecules

• Chemical Formula (CH2O)n
• Molecular Formula C6H12O6
• Structural Formula See pg 51

103
Introductory Question 3

• What two ions form when water disassociates? How
  is pH of 3 different from a pH of 8?
• If the concentration of hydroxide ions
• OH- 1 x 10-3, what would the H be?
• Why are buffers important in a living organism?
  Give an example of a buffer.

104
Acid/Base pH (pg. 39)

• Dissociation of water into a hydrogen ion and a
  hydroxide ion
• Acid increases the hydrogen concentration of a
  solution
• Base reduces the hydrogen ion concentration of
  a solution
• pH power of hydrogen
• Buffers substances that minimize H and OH-
  concentrations (accepts or donates H ions)
• http//www.johnkyrk.com/pH.html

105
pH scale

• The pH scale

H
OH
Lemon juice gastric juice
Increasingly ACIDIC (Higher concentration of H)
Grapefruit juice
Acidic solution
Tomato juice
Urine
NEUTRAL H OH
PURE WATER
Human blood
Seawater
Neutral solution
Increasingly BASIC (Lower concentration of H)
Milk of magnesia
Household ammonia
Household bleach
Oven cleaner
Basic solution
Figure 2.15
106
The chemistry of life is sensitive to acidic and
basic conditions

• A compound that releases H ions in solution is
  an acid (proton donor) , and one that accepts H
  ions in solution is a base (proton acceptor)
• Acidity is measured on the pH scale
• 0-7 is acidic
• 8-14 is basic
• Pure water and solutions that are neither basic
  nor acidic are neutral, with a pH of 7

107
Determining Hydrogen and Hydroxide ion
Concentrations in a Solution

• pH -log10H
• HOH- 1 x 10-14
• Pure water H 10-7

108
Acid precipitation threatens the environment

• Some ecosystems are threatened by acid
  precipitation
• Acid precipitation is formed when air pollutants
  from burning fossil fuels combine with water
  vapor in the air to form sulfuric and nitric acids

Figure 2.16A
109

• These acids can kill fish, damage buildings, and
  injure trees

• Regulations, new technology, and energy
  conservation may help us reduce acid precipitation

Figure 2.16B
110
Buffers

• Cells are kept close to pH 7 by buffers
• Good Example Blood pH 7.4
• CO2 H2O ? H2CO3 ? H HCO3

• Buffers are substances that resist pH change
• They accept H ions when they are in excess and
  donate H ions when they are depleted
• Buffers are not foolproof

111
Chemical Changes in a Reaction
112
Chemical Reaction Example
113
Chemical reactions rearrange matter

• In a chemical reaction
• reactants interact
• atoms rearrange
• products result

2 H2

O2
?
Figure 2.17A
2 H2O
114

• Living cells carry out thousands of chemical
  reactions that rearrange matter in significant
  ways

Beta-carotene
Vitamin A (2 molecules)
Figure 2.17B
115
EXTRA SLIDES
116
Electrolytes vs. Nonelectrolytes

• Electrolytes disassociated substances that form
  ions and are able to conduct electricity.
• Ex. Salts, Acids, and Bases
• Non-electrolytes Substances that dont form ions
  or conduct electricty.
• Ex. Sugars and alcohols

117
Oxidation/Reduction (Redox)

• LEO loses electrons-----Oxidation
• GER gains electrons----Reduction
• Oxidation ex. Rusting iron atom loses electrons
• Reduction refers to reducing any positive charge
  that is present. Oxygen receives electrons very
  easily. Why???
• Important in Cellular Respiration
  Photosynthesis

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Waters hydrogen bonds moderate temperature

• It takes a lot of energy to disrupt hydrogen
  bonds
• Therefore water is able to absorb a great deal of
  heat energy without a large increase in
  temperature
• As water cools, a slight drop in temperature
  releases a large amount of heat