1. The Chemistry of Life Chapter 2 Pages 34 - 59 Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

2. The Nature of Matter What three subatomic particles make up atoms?
How are all of the isotopes of an element similar?
What are the two main types of chemical bonds?
Chapter 2 Section 1
Pages
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

3. Atoms Basic unit of matter Composed of subatomic particles
Proton – positive charge, 1 amu, in nucleus
Neutron – no charge, 1amu, in nucleus
Electron – negative charge, 1/1840 amu, outside nucleus
Atomic Number - # of protons
Mass Number – sum of protons & neutrons
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

4. Element Pure substance made of only one type of atom 6C12 carbon
1H1 hydrogen
8O16 oxygen
7N14 nitrogen
11Na23 sodium
17Cl35 chlorine
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

5. Isotope same different number of protons number of electrons
chemical properties
different
number of neutrons
mass
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Created by C. Ippolito
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6. Radioactive Isotopes have unstable nuclei nuclear particles break down
break down at constant rate
release energy
Trace biochemical pathways
Kill cancer cells
Kill bacteria
Date geological layers
Date fossils
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

7. Chemical Compounds pure substances chemical formula – shorthand
chemical combination
two or more elements
in definite proportions
chemical formula – shorthand
water – H2O
salt – NaCl
ammonia – NH3
carbon dioxide – CO2
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

8. Chemical Bonds electrons around nuclei interact to form compounds
Ionic Bond
transfer of electrons
positive ion loses
negative ion gains
forms a salt
Covalent Bond
share electrons
single bond two shared
double bond four shared
triple bond six shared
Updated 11/11/2005
Created by C. Ippolito
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9. Van der Waals Forces some covalent bonds do not share electrons equal
molecules are attracted to each other
gecko climbs glass
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Created by C. Ippolito
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10. Properties of Water Why are water molecules polar?
What are acidic solutions?
What are basic solutions?
Chapter 2 Section 2
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Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

11. Water Molecule Polarity uneven distribution of electrons between atoms
8 protons of oxygen attracts electrons
electrons spend more time near oxygen
has slightly negative charge
negative pole
1 proton of hydrogen not as attractive
has slightly positive charge
positive pole
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

12. Water Molecule Hydrogen Bonds Cohesion Adhesion
negative side (O) attracts positive side (H)
forms “weak” bond
Cohesion
attraction of similar molecules (water to water)
Adhesion
attraction of different molecules (water to glass)
capillary action – draws water up thin tubes
meniscus of graduate
water up stems and leaves
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

13. Solutions and Suspensions
Mixture – material of two or more substances
physically mixed but not chemically combined
salt and pepper; sand and gravel
Solution – mixture substances indistinguishable
salt and water; sugar and water; coffee; tea
solute – material that is dissolved (less present salt)
solvent – material that dissolves (more present water)
Suspension – mixture substances separate
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

14. Acids, Bases, pH Water molecules can separate to form ions
pure water H+ = OH-
neutral
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

15. The pH Scale System used to concentration of H+ ions in a solution.
pH scale has values from 0 to 14
7 is neutral; H+ = OH-; pure water
below 7 H+ > OH- ; acidic solution
above 7 OH- > H+ ; basic solution
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

16. Acids substance that forms H+ ions in solution Acid Indicators
ph 1-3 are strong acids
HCl – hydrochloric acid in stomach aids digestion
taste sour
burn to touch
Acid Indicators
blue litmus changes from blue to red
bromthymol blue changes from blue to yellow
methyl orange changes from orange to red
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

17. Bases substance that forms OH- ions in solution Acid Indicators
ph are strong bases
NaOH – base found in Drano
CaOH – base found in antacid Tums
MgOH – base found in antacid Milk of Magnesia
taste bitter
slippery to touch
Acid Indicators
phenolphthalein changes from clear to pink
bromthymol blue changes from yellow to blue
red litmus changes from red to blue
Updated 11/11/2005
Created by C. Ippolito
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18. Buffers
weak acids or bases that react with strong acids or bases to prevent sudden changes in pH
cells maintain homeostasis using buffers to keep pH between 6.5 and 7.5
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

19. Carbon Compounds
What are the functions of each group of organic compounds?
Chapter 2 Section 3
Pages
Updated 11/11/2005
Created by C. Ippolito
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20. The Chemistry of Carbon
Organic Compounds – compounds in living things
carbon compounds
4 valance electrons – form 4 bonds
long chain molecules
Inorganic Compounds – compounds in non living things
Updated 11/11/2005
Created by C. Ippolito
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21. Macromolecules giant compounds formed by polymerization
many small molecules bonded together
Monomer – small molecule used to form macromolecules
Polymer – formed by many monomers joined together
Updated 11/11/2005
Created by C. Ippolito
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22. Macromolecule Groups Carbohydrates – main energy sources
Lipids – store energy
Nucleic Acids – store genetic information
Proteins – biological catalyst
Updated 11/11/2005
Created by C. Ippolito
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23. Carbohydrates C:H:O ratio of 1:2:1 building block – simple sugars
main source of energy (glucose)
short term energy storage (starch)
form plant structures (cellulose in cell wall)
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

24. Lipids C H O long chains of carbon and hydrogen
building block – fatty acids & glycerol
long term energy storage
part of membranes
waterproof coverings
Saturated – maximum H
Unsaturated – less H
Polyunsaturated – least H
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

25. Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

26. Nucleic Acids C H O N P building block – nucleotide
5 carbon sugar
phosphate group
nitrogen base
stores genetic information
Deoxyribonucleic Acid (DNA) – deoxyribose
Ribonucleic Acid (RNA) - ribose
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

27. Proteins C H O N building block – amino acids have unique 3-D shapes
Amino group (–NH2)
Carboxyl group (–COOH)
Variable group (-R)
catalyst
regulate cell processes
transport molecules
fight disease
have unique 3-D shapes
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

28. Chemical Reactions and Enzymes
What happens to chemical bonds during chemical reactions?
How do energy changes affect whether a chemical reaction will occur?
Why are enzymes important to living things?
Chapter 2 Section 4
Pages
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

29. Chemical Reaction
Process that changes one set of chemicals into another set of chemicals
Reactants – chemicals that enter a reaction
Products – chemicals produced by a reaction
Chemical Equation – represents a reaction
CO2 + H2O → H2CO3 occurs in blood
H2CO3 → CO2 + H2O occurs in lungs
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

30. Energy in Reactions reactants have more energy than products
release energy
work spontaneously
products have more energy than reactants
absorb energy
need energy source to work
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

31. Enzymes biological catalysts lower the activation energy
Catalyst – substance that speeds up the rate of a chemical reaction
lower the activation energy
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

32. Lock and Key Theory enzyme has an active site. enzyme Active Site
holds the substrates - materials the enzyme catalyzes
enzyme
Active Site
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

33. Substrate fits into Active Site
Substrates fit in enzyme shape
Updated 11/11/2005
Created by C. Ippolito
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34. Enzyme Substrate Complex
substrates held together
form the enzyme substrate complex
lowers the activation energy
new molecule forms
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

35. Catalysis is completed
The enzyme releases the combined substrates and is now free to repeat the process.
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004

36. Regulation of Enzyme Activity
All change the shape of the active site:
pH - alters enzyme shape
most work at an optimum pH
Temperature - alters enzyme shape
optimum temperature 37°C in human cells
high temperatures denature proteins
Enzyme/Substrate Concentration - a maximum is reached then levels off.
Updated 11/11/2005
Created by C. Ippolito
July 13, 2004