Chapter 5: Molecules of Life AP Biology Chapter 5: Molecules of Life

LE 5-2 Short polymer Unlinked monomer Dehydration removes a water molecule, forming a new bond Longer polymer Dehydration reaction in the synthesis of a polymer Hydrolysis adds a water molecule, breaking a bond Hydrolysis of a polymer

Carbohydrates See the Carbonyls and Hydroxides?

Dry vs. Wet

LE 5-5 Dehydration reaction in the synthesis of maltose Glucose 1–4 glycosidic linkage Glucose Glucose Maltose Dehydration reaction in the synthesis of sucrose 1–2 glycosidic linkage Glucose Fructose Sucrose

Fig: 5.6

Fig: 5.7

Cellulose microfibrils in a plant cell wall LE 5-8 Cellulose microfibrils in a plant cell wall Cell walls Microfibril 0.5 µm Plant cells Cellulose molecules b Glucose monomer

Chitin

Lipids

Dehydration reaction in the synthesis of a fat LE 5-11a Fatty acid (palmitic acid) Glycerol Dehydration reaction in the synthesis of a fat

Fat molecule (triacylglycerol) LE 5-11b Ester linkage Fat molecule (triacylglycerol)

Saturated vs. Unsaturated

Fig: 5.13

Cell Membranes

Steroid Structure

LE 4-9 Estradiol Female lion Testosterone Male lion

Atherosclerosis

Proteins

LE 5-UN78 a carbon Amino group Carboxyl group

Fig: 5.17a

Fig: 5.17b

Peptide Bonding

Fig: 5.20 – Insulin 1’ sequence

Fig: 5.21

LE 5-21b Normal hemoglobin Sickle-cell hemoglobin Primary structure Val His Leu Thr Pro Glu Glu Primary structure Val His Leu Thr Pro Val Glu 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Exposed hydrophobic region Secondary and tertiary structures Secondary and tertiary structures b subunit b subunit a a   Quaternary structure Normal hemoglobin (top view) Quaternary structure Sickle-cell hemoglobin a   a Function Molecules do not associate with one another; each carries oxygen. Function Molecules interact with one another to crystallize into a fiber; capacity to carry oxygen is greatly reduced.

2’ structure

LE 5-20d Hydrophobic interactions and van der Waals interactions Polypeptide backbone Hydrogen bond Disulfide bridge Ionic bond

3’ Structure

4’ Structure

Protein’s Natural Form

Denaturation of a protein

Fig: 5.23

Complimentary Base Pairing

Fig: 5.26

Fig: 5.27

Watson and Crick

Genes and Evolution