1 Chapter 2-- Study Guide 1.Critically read Chapter 2 pp before “ENZYMES AND METABOLISM” section 2.Comprehend Terminology (those in bold in the textbook) 3.Study-- Figure questions, Think About It questions, and Before You Go On (section-ending) questions 4.Do end-of-chapter questions: –Testing Your Recall— 6 to 10, –True or False– 1 3, 5, 6, 7

§ 2.4 Organic Compounds 2

3 § Organic compounds — Def.--Compounds of carbon The organic molecules of life— 4 groups: carbohydrates, lipids,... Functional groups of organic molecules— a group of atoms that determines the functional characteristics of an organic molecule For example– Fig. 2.14

(See next slide) 4

ATP (adenosine triphosphate) ̶ A Nucleotide three _______________ groups Sugar; ribose Base; adenine 5

6 § Monomers and polymers — Polymers– molecules made of a repetitive series of identical or similar ___________ For example, starch is a polymer of about 3,000 glucose monomers Mechanism (how?) by poly ____ – this above process; also called dehydration synthesis (OR condensation) Fig. 2.15

Which is polymerization reaction, A or B? A. B. Give an example of polymerization. 7

8 § Carbohydrates — Hydrophilic molecules– Why? General formula (CH 2 O) n 1. Monosaccharides (simple sugars)— glucose, fructose, and galactose; isomers of each other (C 6 H 12 O 6 ) Fig. 2.16

Fig Three monosaccharides; hydroxyl groups? Where are carbon atoms? Disaccharides-- next slide 9

2. Disaccharides Milk sugar A product of starch digestion Glucose + Fructose 10

3A. Polysaccharide– long chains of glucose (Glucose, glu.) Can we make glycogen? Glu. 11 Starch and cellulose next slide

12 § Carbohydrates (continued)— 3B. Other polysaccharides– Starch—energy-storing molecules in plants; when sunlight + nutrients is not available, plants use starch as energy C____________—structural molecule of cell walls; can we digest it? Why? For example, wood, cotton etc.

13 § Carbohydrates (continued)— 4. conjugated carbohydrates – Bound to proteins (a) & lipids (glycolipids, cell surface coat) Example— a. glycoproteins; major component of mucus; where? b. Proteoglycans– hold cells and tissues together; gelatinous filler in the eye; in the joints etc.

Review Table 2.6, a summary of carbohydrate functions: 1. Monosaccharides 2. Disaccharides 3. Polysaccharides 4. Conjugated carbohydrates 14

15 § Lipids — Hydrophobic molecules; Why? Include C, H, and O; with high ratio of hydrogen to oxygen Ex. C 57 H 110 O 6 (tristearin) vs. (CH 2 O) n Less oxidized than carbohydrates; more calories per gram Several major types of lipids in humans Table 2.7

Steroids 16

2.--Triglyceride synthesis Is this a dehydration synthesis or hydrolysis reaction? Fatty acids Glycerol 17

3.--Fig Lecithin, a phospholipid 18 Next slide

Fig. 2.20c– A simplified representation of the phopholipid molecule Why is a phospholipid amphiphilic? 19

4.--Fig A prostaglandin, Eicosanoids Five of the carbon atoms are arranged in a ring. Functions-- 20

5.—Fig Cholesterol All steroids have this basic four- ringed structure. Functions—? Next slide 21

Cholesterol — 1.(Where?) Cholesterol is found only in animals (natural product); from where? 2.Related to cardiovascular disease (INSIGHT 2.3—Good and bad cholesterol; p. 76) 3.Function-- –Precursor of steroids –Important component of cell membrane

23 § Amino acids & proteins — A protein is a polymer of amino acids A amino acid has a central carbon atom with an amino and a carboxyl group bound to it The radical (R) group makes each of the 20 amino acid unique Essential a.a.--? Fig. 2.23

R groups Similarities of all a.a.? 24

25 § Amino acids & proteins (continued)— Joining of amino acids– by peptide bonds– to form peptides Fig. 2.23, 2.25

Is this a dehydration synthesis or hydrolysis reaction? a.a. #2 26

Fig primary structure of insulin § Protein structure 27

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29 § Amino acids & proteins (continued)— Tertiary structure– folding into globular and fibrous shapes –Globular proteins– a ball of yarn; Ex. enzymes and antibodies –Fibrous proteins– slender filaments; muscle contraction proteins--

30 § Protein functions— 1.Structure– Keratin gives strength to nails, hair, and skin surface 2.Communication– oxytocin (a ligand) binds to a protein (its receptors) 3.Membrane transport channels— Sodium and potassium channels 4.Catalysis– enzymes etc.

Check Point Questions A.Use the simplified phospholipids (each with a head and two wavy tails) to construct a portion of a cell membrane. B.Point out the polar region and the nonpolar regions. 31