Chapter 1 review

Question 1

All chiral amino acids are S/R

Answer 1

All chiral amino acids are S

Question 2

Cysteine is chiral (T/F)

Answer 2

T

Question 3

_____ is chiral but is R configuration

Answer 3

Cysteine

Question 4

What is an amino acid that is not chiral

Answer 4

Glycine

Question 5

R group of glycine

Answer 5

H

Question 6

Nonpolar, nonaromatic amino acids

Answer 6

GAVL IMP
Glycine, Alanine, Valine, Leucine, Isoleucine, Methionine, Proline

Question 7

Aromatic amino acids

Answer 7

Tryptophan, phenylalanine, tyrosine

Question 8

Polar amino acids

Answer 8

SAT GC
Serine, Asparagine, Threonine, Glutamine, Cysteine

Question 9

Negatively charged amino acids

Answer 9

Aspartate, glutamate

Question 10

Positively charged amino acids

Answer 10

Lysine, Arginine, Histidine

Question 11

Term used to describe having both the ability to donate or receive protons

Answer 11

Amphoteric

Question 12

pKa definition

Answer 12

pH at which half of the species are deprotonated

Question 13

At pH near pI, amino acids are in their _____ form

Answer 13

Zwitterion

Question 14

Formula to calculate pI for uncharged amino acid

Answer 14

Averaging two pKa values

Question 15

Briefly describe the titration curve for an amino acid

Answer 15

Nearly flat at pKa values of amino acid. Nearly vertical at pI of amino acid

Question 16

Amino acid with charged side chain has additional pKa value. How is this calculated?

Answer 16

Average of pKa value at which zwitterion is protonated and deprotonated

Question 17

pI of amino acid without charged side chain

Answer 17

6

Question 18

Acidic amino acid pI

Answer 18

Below 6

Question 19

Basic amino acid pI

Answer 19

Above 6

Question 20

What is the amino acid responsible for interrupting the secondary structure?

Answer 20

Proline

Question 21

Name the interaction responsible for pushing hydrophobic R groups to the interior of the protein

Answer 21

Hydrophobic interaction

Question 22

Describe what a disulfide bond is

Answer 22

Two cystine molecules are oxidized and create a covalent bond to form cysteine

Question 23

Name of proteins with covalently attached molecules

Answer 23

Conjugated proteins

Question 24

Name of group covalently attached to conjugated proteins. Give examples.

Answer 24

Prosthetic groups. Metal ions, vitamins, lipid, carbs, nucleic acid

Question 25

Two ways denaturation can happen

Answer 25

1. Heat
2. Solvent (solute concentration)