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Chapter 2-- Study Guide

1. Critically read Chapter 2 pp. 59-69 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, 15-17– True or False– 1 3, 5, 6, 7

§ 2.4 Organic Compounds

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§ 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

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§ 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

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§ Carbohydrates —

• Hydrophilic molecules– Why?

• General formula (CH2O)n

• 1. Monosaccharides (simple sugars)—glucose, fructose, and galactose; isomers of each other (C6H12O6)

Fig. 2.16

Fig. 2.16-- Three monosaccharides; hydroxyl groups?

Where are carbon atoms?

Disaccharides-- next slide

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2. Disacch

arides

Milk sugar

A product of starch digestion

Glucose + Fructose

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3A. Polysaccharide– long chains of glucose (Glucose, glu.)

Can we make glycogen?

Glu.

Glu.Glu.

Glu.

Glu.Glu. 11

Starch and cellulose next slide

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§ 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.

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§ 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. Monosaccharides2. Disaccharides3. Polysaccharides4. Conjugated carbohydrates

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§ Lipids —• Hydrophobic molecules; Why?• Include C, H, and O; with high ratio of

hydrogen to oxygen

Ex. C57H110O6 (tristearin) vs. (CH2O)n

• Less oxidized than carbohydrates; more calories per gram

• Several major types of lipids in humans

Table 2.7

Stero

ids

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2.--Triglyceride synthesis

Is this a dehydration synthesis or hydrolysis reaction?

1.--3 Fatty acids

Glycerol

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3.--Fig. 2.20 Lecithin, a phospholipid

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Next slide

Fig. 2.20c– A simplified representation of the phopholipid molecule

Why is a phospholipid amphiphilic?

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4.--Fig. 2.21 A prostaglandin, Eicosanoids

•Five of the carbon atoms are arranged in a ring. •Functions--

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5.—Fig. 2.22 Cholesterol

All steroids have this basic four-ringed structure.

Functions—? Next slide

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5.--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

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§ 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.?

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§ 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

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Fig. 2.25 primary structure of insulin

§ Protein structure

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§ 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--

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§ Protein functions—1. Structure– Keratin gives strength to

nails, hair, and skin surface2. Communication– oxytocin (a ligand)

binds to a protein (its receptors)3. Membrane transport channels—

Sodium and potassium channels4. 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.

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