Amino Acids

Question 1

Glucogenic AA

Answer 1

Carbon skeleton that is converted to intermediates that can be used to synthesize glucose.

Question 2

Ketogenic AAs

Answer 2

Carbon skeleton is converted to intermediates that can form ketone bodies or fatty acides

Question 3

What are the essential amino acids

Answer 3

TV FILM HWK

-must be obtained from diet

Question 4

What are the glucogenic nonessential aa’s?

Answer 4

DARN CEQ GPS

Question 5

What are the essential glucogenic

AAs?

Answer 5

H MTV

Question 6

Both nonessential ketogenic and gluconenic AAs

Answer 6

Tyrosine

Question 7

Ketogenic nonessential

Answer 7

none

Question 8

Essenstial both

Answer 8

FIW

Question 9

Essential Ketones

Answer 9

LK

Question 10

What are the characteristics of peptide bonds in AA residues?

Answer 10

• linear and planar
• not free to rotate; resonance
• trans: H of amino group is trans to carbonyl group

Question 11

Bond length of of peptide bond

Answer 11

planar bond: 1.32 A

-peptide bond is uncharged

Question 12

Tans orientation is favored by peptide bond but the exception observed for X-pro is

Answer 12

Proline (cis)

Question 13

What is Phi angle and Psi?

Answer 13

Phi: N-C alpha (-80)
Psi: C(alpha)-C (+85)

phi and psi are single bonds

Question 14

Tertiary Structure

Answer 14

folding of polypeptide chain as a result of interactions between R groups.

Ex: helix turn helix

• helix loop helix
• zinc fingers
• leucine zipper

Question 15

Quaternary Structure

Answer 15

interaction of different polypeptide chains to form a functional protein

Question 16

Secondary structure

Answer 16

Hydrogen bonding between carboxyl oxygen and nitrogen hydrogen of the peptide chain (back bone)

• alpha helix
• beta sheets
• beta turns
• omega loop

Question 17

How can alpha helix be disrupted?

Answer 17

proline

• large charged amino acids
• bulky side chains (W)
• amino acids with branched R groups (V,I)

Question 18

What stabilizes the hydrogen bonding between alpha helix

Answer 18

-carbonyl oxygen
-NH group of peptide
(every fourth AA)

Question 19

How may AAs per turn of alpha helix and where do r groups extend to?

Answer 19

3. 6 AA per turn

- R groups extend outward

Question 20

What are proteins that contain only alpha helixes?

Answer 20

Ferritin, Hemoglobin

Question 21

What do beta bends in beta pleated sheet contain? adjacent aa are seperated by how many angstroms

Answer 21

proline and glycine

-3.5 A

Question 22

What are proteins that contain mostly beta sheets?

Answer 22

fatty acid binding protein

green flourescent protein

Question 23

Loops and turns connect elements of secondary structure to form domains of

Answer 23

omega loops

and beta turn (hairpin)

Question 24

tertiary Folding of polypeptide chain results in interaction between what

Answer 24

r-groups

Question 25

Quaternary Structure examples

Answer 25

hemoglobin, myoglobin

Question 26

Denaturing protein

Answer 26

unfolding and disorganization of proteins secondary and tertiary structure

Question 27

How to denature a protein?

Answer 27

- does not involve hydrolysis of peptide bonds. - Denaturing agents: heat, organic solvents, urea, guanidium chloride, detergents (SDS), change in pH, heavy metals -reducing agents: beta mercaptoethanol

Question 28

Beta mercaptoethanol

Answer 28

Reduces disulfide bonds

Question 29

How is Alpha Keratin helizes cross linked?

Answer 29

- Van der Waals forces - ionic interactions - disulfide bonds contains heptad repeat; each alpha helix contain 3.5 residues/ turn

Question 30

Collagen describe the structure

Answer 30

Composed of long, rigid alpha CHAINS, wrapped around in LEFT handed triple helix

Question 31

Collagen Amino ACid composition

Answer 31

- glycine - proline - often proline and lysine are hydroxylated

Question 32

What is required in hydrolylation of proline of collagen ?

Answer 32

- prolyl hydroxylase - requires vitamin C - molecular oxygen Location: 4 and 3 hydroxyproline

Question 33

Hydroxylation of lysine allows for cross linking. what is the enzyme used

Answer 33

lysl hydoxylase

Question 34

Osteogenesis Imperfecta tarda

Answer 34

Defects in collagen 1 - mutation of alpha 1 or alpha 2 - substitution of AA other than glycine - bulky side chain prevents proper folding in alpha chains into helix

Question 35

Osteogenesis Imperfecta congenital

Answer 35

type 2 collagen defect

Question 36

What is the purpose of the denaturation and renaturation period?

Answer 36

Ribonuclease: 124 AA 4 disulfide bonds -105 combinations; only 1 combination produces enzymatic activity

Question 37

Differentiate between the two misfolded protein diseases

Answer 37

Alzeimers: accumulates in nonbranching fibrils with beta pleated sheet prion disease (neurons and glial cells): lacks primary sequence differences in postranslational modification.

Question 38

Living systems contain what direction of amino acids

Answer 38

L amino acid

Question 39

What does the aromatic AA participate in

Answer 39

hydrophobic bonding - binding planar ligands via Van der Waals - tyrosine may hydrogen bond or donate a catalysis

Question 40

where is serine found in enzymes

Answer 40

active site

Question 41

Where are the basic aa found

Answer 41

surface and may be found in catalysis or metal binding

Question 42

Ramachandran diagram disfavors phi an psi bonds in

Answer 42

beta strands and alpha helixes

Question 43

What does the concentration of disulfide bonds do in hair and wool vs horns, claws

Answer 43

More disulfide bonds, make them harder (horns) | hair and wool: less disulfide bonds-more stretchable

Question 44

triple helix structure

Answer 44

1000 amino acids 3 amino acids per turn each alpha chain adapts left handed helix

Question 45

PRotein folding

Answer 45

all or none process | -brings amino acid R groups together in active site