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Unit 1: The Chemistry of Life. Chapter 2. Atoms Combine to Form Molecules. Energy is the capacity to do work Joining atoms into molecules requires energy Stored energy = potential energy Separating atoms from molecules releases energy that is stored in the broken bonds
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Unit 1: The Chemistry of Life Chapter 2
Atoms Combine to Form Molecules • Energy is the capacity to do work • Joining atoms into molecules requires energy • Stored energy = potential energy • Separating atoms from molecules releases energy that is stored in the broken bonds • Energy in motion, doing work = kinetic energy Slide 2.3 .
Chemical Bonds • Ionic • Covalent • Hydrogen
Water Chapter 3
Life Depends on Water • Water molecules are polar (they have slight electrical charges) + + - Slide 2.6
Water • High Specific Heat • High heat of vaporization • Evaporitive Cooling • Adhesion/Cohesion • Less dense as a solid • Water is an excellent solvent
Water Keeps Ions in Solution Figure 2.8 Slide 2.8
pH Scale • Acids donate H+ ions (HCl & H2SO4) • Bases donate OH- ions (NaOH & KOH)
0 • The following are pH values: cola-2; orange juice-3; beer-4; coffee-5; human blood-7.4. Which of these liquids has the highest molar concentration of OH-? • cola • orange juice • beer • coffee • human blood
Based on your knowledge of the polarity of water, the solute molecule is most likely * positively charged. negatively charged. neutral in charge. hydrophobic. nonpolar.
If the pH of a solution is increased from pH 8 to pH 9, it means that the • concentration of H+ is 10 times greater than what it was at pH 8. • concentration of H+ is 100 times less than what it was at pH 8. • concentration of OH- is 10 times greater than what it was at pH 8. • concentration of OH- is 100 times less than what it was at pH 8. • concentration of H+ is greater and the concentration of OH- is less than at pH 8.
Macromolecules Chapters 4 & 5
Elements of Living Organisms Table 2.2 Slide 2.5
Making and Breaking Biological Macromolecules: Dehydration Synthesis and Hydrolysis Figure 2.13 Slide 2.13
Dehydration Synthesis is the Reverse of Hydrolysis • Dehydration synthesis • Removes equivalent of a water molecule to link molecular units • Requires energy (Process of ANABOLISM) • Hydrolysis • Adds the equivalent of a water molecule to break apart macromolecules • Releases energy (Process of CATABOLISM) Slide 2.14
Fig. 5-12 Structural formula of a saturated fat molecule Stearic acid, a saturated fatty acid (a) Saturated fat Structural formula of an unsaturated fat molecule Oleic acid, an unsaturated fatty acid cis double bond causes bending (b) Unsaturated fat
0 • What happens when a protein denatures? • It loses its primary structure. • It loses its secondary and tertiary structure. • It becomes irreversibly insoluble and precipitates. • It hydrolyzes into component amino acids. • Its hydrogen bonds, ionic bonds, and peptide bonds are disrupted.
Enzymes Chapters 5 & 8
Fig. 8-UN2 Course of reaction without enzyme EA without enzyme EA with enzyme is lower Reactants Free energy Course of reaction with enzyme ∆G is unaffected by enzyme Products Progress of the reaction
AP Lab #2 Enzyme Catalysis
0 • A solution of starch at room temperature does not decompose rapidly to a sugar solution because • the starch solution has less free energy than the sugar solution. • the hydrolysis of starch to sugar is endergonic. • the activation energy barrier cannot be surmounted in most of the starch molecules. • starch cannot be hydrolyzed in the presence of so much water. • starch hydrolysis is nonspontaneous.
0 • Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? • denaturization of the enzyme • allosteric inhibition • competitive inhibition • noncompetitive inhibition • insufficient cofactors
Which of the following represents the ∆G of the reaction? a b c d e 0
0 • Which of the following would be the same in an enzyme-catalyzed or -uncatalyzed reaction? • a • b • c • d • e
Unit 2: The Cell Cell Structure & Function -different types of cells (Ch. 6) -organelle functions (Ch. 6) -membrane structure & transport (Ch. 7)