Ch.4 The Molecule of Life

Amino acids not included

Macromolecules

large and usually polymers

• All but lipids are polymers

Dehydration

removes a water molecule forming a new bond

Hydrolysis

adds a water molecule breaking a bond

Carbohydrates

serves as fuel and building material

• monosaccharides (single sugar)

• disaccharides (two)

• polysaccharides (long chain)

Glucose (C₆H₁₂O₆₎

most common monosaccharide

monosaccharide

classified by location of carbonyl group + # of C in carbon skeleton

Trioses

3 carbon sugars (C₃H₆O₃)

Pentoses

5 carbon sugars (C₅H₁₀O₅)

• Ribose

Hexoses

6 carbon sugars (C₆H₁₂O₆)

• Glucose + Fructose

Disaccharide

formed when a dehydration reaction joins 2 monosaccharides

• Covalent bond called glycosidic bond

Starch

“storage polysacharide”

plants, consists entirely of glucose membrane

• amylose

Glycogen

“storage polysacharide”

animals, humans + other vertebrates store mainly in liver and muscle cells

Cellulose

“structural polysacharide”

major component of the tough wall of plant cells

• differ in glycosidic linkages

Alpha (α) vs Beta (β) rings

• Alpha- below

• Beta- above

• Enzymes that digest starch by hydrolyzing α linkages cant hydrolyze β linkages in cellulose

Chitin

“structural polysacharide”

found in exoskeleton of arthropods and the cell walls of many fungi

• Polymer of N-acetylglucosamine

Lipids

DO NOT FORM POLYMERS

Little or no affinity for water (hydrophobic)

• fats, phospholipids, steroids

Fats

3 fatty acids joined to glycerol by an ester linkage, creating a triacylglyercol

• main function energy storage

• very in length + location of double bonds

Saturated fatty acids

max # of H atoms + no double bonds

Unsaturated fatty acids

one or more double bonds

Hydrogenation

process of adding H

• creates unsat. fats with trans double bonds = cardiovascular disease

Phospholipids

2 fatty acids (hydrophobic) + a phosphate group (hydrophilic head) are attached to glycerol

Steroids

lipids characterized by a C-skeleton consisting of 4 fused rings

• Cholesterol

Proteins (8)

“account for more than 50% of dry mass of cells”

1. Enzymes

2. Defense (immune)

3. Storage (egg albumin)

4. Transport (hemoglobin)

5. Structural (collagen)

6. Motor (myosin)

7. Receptor (serration)

8. Hormonal (insulin)

Amino Acids

have carboxyl + amino groups

• “R groups” distinguish them

• linked by peptide bonds

Polypeptide

polymer of amino acids

• 2 to 1000 amino acids with unique sequence

Shapes of protein (3)

1. Ribbon

2. Space-filling

3. Wire-frame

lvls or proteins (4)

1. Primary- sequence of amino acids

2. Secondary- stabilize by H-bonds between (α helix + β pleated sheet)

3. Tertiary- how α helix + β pleated sheet come together (disulfide bridge)

4. Quarternary- polypetide subunit form 1 macromolecule

Denaturation vs Renaturation

unfolding vs folding of protein

Deoxyribonucleic (DNA)

“nucleic acid”

info containing molecule, form double helix

• makes RNA

Ribonucleic Acid (RNA)

“nucleic acid”

transfer molecule

• makes protein

Nucleic Acids

made of monomers called nucleotides

• N base, pentose sugar, phosphate group (no nucleoside)

DNA base pairings

1. Adenine (A) with Thymine (T)

• T replaced with uracil (U) in RNA

1. Guanine (G) with Cytosine (C)