biochem

Question 1

pKa definition

Answer 1

pH at which the amount of protonated and deprotonated molecules of a species are equal

Question 2

pH < pKa

Answer 2

majority of species will be protonated

Question 3

pH > pKA

Answer 3

majority of species will be deprotonated

Question 4

what is the tendency of ionizable groups in different pHs

Answer 4

tend to gain protons in acidic conditions and lose protons in basic conditions

Question 5

pKa of carboxyl group

Answer 5

2

Question 6

pKa of amino group

Answer 6

btw 9 and 10

Question 7

pH = pKa

Answer 7

concentrations between the two ions are equal, buffering activity, titration curve is flat

Question 8

pI

Answer 8

isoelectric point, the pH at which every molecule is electronically neutral

Question 9

calculate pI for uncharged side chains

Answer 9

average pKas

Question 10

calculate pI for acidic side chains

Answer 10

average pKa of R group and carboxylic acid group

Question 11

calculate pI for basic side chains

Answer 11

average pKa of R group and amino group

Question 12

general pI for acidic side chains

Answer 12

low pI

Question 13

general pI for basic side chains

Answer 13

high pI

Question 14

trypsin and chymotrypsin

Answer 14

hydrolytic enzymes, digest proteins by adding H+ to amide nitrogen and OH to carbonyl carbon

Question 15

From what terminal to what terminal are poly peptides usually drawn?

Answer 15

N to C

Question 16

What type of bond is a peptide bond?

Answer 16

covalent

Question 17

primary protein structure

Answer 17

order of aas with peptide bonds

Question 18

secondary protein structure

Answer 18

alpha helix and beta sheets, hydrogen bonds

Question 19

alpha helix and ex

Answer 19

clockwise, keratin

Question 20

beta sheet and ex

Answer 20

parallel or antiparallel, fibroin

Question 21

proline in secondary protein structure

Answer 21

kinks, start of alpha helix, turns of beta sheets

Question 22

tertiary protein structure

Answer 22

3D, hydrophil/phob interactions, disulphide (btw cysteins)

Question 23

denaturation

Answer 23

lose tertiary structure

Question 24

what are some examples of things that cause denaturation

Answer 24

heat, urea, SDS