Protein Structure

Question 1

primary structure of protein

Answer 1

amino acid sequences

Question 2

dipeptide bond

Answer 2

two amino acids connect via condensation
NH3 bonds to COOH, becomes C=O bonded to NH

Question 3

4 character of peptide bond

Answer 3

partial double bond character
rigid & planar
trans configuration
uncharged yet polar

Question 4

secondary structure

Answer 4

local fold adjacent to 3D

Question 5

four types of secondary structures

Answer 5

alpha helices, beta sheet, beta turn, beta loop

Question 6

main forces creates secondary structure

Answer 6

H bond

Question 7

what bonding used to maintain alpha helix?

Answer 7

intrachain hydrogen bond
alpha nitrogen & 4th distinct amino acid

Question 8

how many residue per turn in alpha helix?

Answer 8

3.6 (basically 4)

Question 9

what AA disrupt aplha helices?

Answer 9

proline & glycine

Question 10

What type of AA disrupt alpha helices?

Answer 10

charged and bulky R groups

Question 11

why does proline disrupt alpha helices?

Answer 11

too rigid

Question 12

why does glycine disrupt alpha helices?

Answer 12

too flexible (all H bonds)

Question 13

Beta sheets stabilize against each other using?

Answer 13

H bonding

Question 14

what beta sheet type is twisted into fibrils & result in Alzheimer & Huntington?

Answer 14

Amyloid protein (ABeta)

Question 15

What beta sheets does protein aggregation happen in for Huntington?

Answer 15

poly glutamine, beta strands, huntingtin protein

Question 16

Prions cause mad cow disease by inducing formation of what?

Answer 16

amyloid fold (aggregate tight pack B sheet)

Also Creutzfeldt-Jakob Disease

Question 17

Porin

Answer 17

transmembrane protein in outer membrane of gram negative bactria that act as channel

Question 18

beta turn

Answer 18

secondary protein structure revers direction of polypeptide chain

Question 19

What type of amino acids are use in beta turns?

Answer 19

charged, typically proline & glycine as disruptive

Question 20

how many AA in beta turn?

Answer 20

four

Question 21

stabilisation forces for beta turns

Answer 21

H bonds and electrostatic interactionsw

Question 22

where are H bonds in Bturns?

Answer 22

1st and 4th AA

Question 23

2 classes of tertiary structure

Answer 23

globular & fibrous

Question 24

examples globular protein

Answer 24

enzyme, transport

Question 25

main example fibrous protein

Answer 25

collagen, elastin, keratin

Question 26

forces create tertiary

Answer 26

H bond, disulfide bond, hydrophobic interaction, electrostatic interaction

Question 27

what is protein denaturation

Answer 27

loss of original tertiary structure

Question 28

True/False: most proteins can revert to their original tertiary structure after dénaturation?

Answer 28

False: only ribonuclease can refold on its own- all others are permanently altered

Question 29

quarternary structure?

Answer 29

association of multimeric proteins

Question 30

forces of quarternnary structure

Answer 30

H bonds, hydrophobic interactions, electrostatic interactions

Question 31

Sickle cell disease changes to AA

Answer 31

change glutamine reside to caline, causing more fibrous hemoglobin folding so can’t hold oxygen