Protein Structure and Function

Question 1

Biological functions of proteins

Answer 1

Structural
Movement
Enzymes
Transport
Membrane transport
Hormones
Receptors
Defence
Gene regulation
Chromosome separation

Question 2

Which amino acid has the NH3 group?

Answer 2

First
N terminal end

Question 3

Which amino acid has the COOH group?

Answer 3

Last
C terminal end

Question 4

Glycosylation

Answer 4

Addition of sugar

Question 5

Primary structure

Answer 5

Sequence of amino acids in protein chain

Question 6

Secondary structure

Answer 6

Folding/coiling of peptide chain (alpha helix or beta pleated sheet)

Question 7

Tertiary structure

Answer 7

Peptide chain folds upon itself

Question 8

Quaternary structure

Answer 8

Folded peptide chains join

Question 9

Alpha helix structure

Answer 9

H bonds in the same polypeptide chain
H bonds between peptide bond Carbonyl O and H of N-H every 4th peptide
R groups on the outside

Question 10

Beta pleated sheet

Answer 10

Linear peptide chains
H bonding between peptide chains

Question 11

Types of beta sheet structures

Answer 11

Antiparallel sheet
Parallel sheet

Question 12

Collagen structure

Answer 12

3 chains
H bonds between chains

Question 13

Features of an alpha helix protein

Answer 13

Globular
Compact together

Question 14

Features of a beta sheet protein

Answer 14

High tensile strength
No elasticity

Question 15

Forces that stabilise protein structure

Answer 15

Disulphide bridges
Hydrogen bonds
Electrostatic interactions
Van der Waals forces
Hydrophobic effect

Question 16

Conditions that proteins are sensitive to

Answer 16

pH
Temperature
Ionic strength

Question 17

Features of a peptide bond

Answer 17

Shorter than C-N bond
No rotation
Delta negative charge on Oxygen
Delta positive charge on Nitrogen

Question 18

PKU

Answer 18

Cannot breakdown phenylalanine
Reduced Tyrosine production
Reduced hormones eg dopamine and melanin

Question 19

Cause of albinism

Answer 19

Defective tyrosinase
Tyrosine cannot breakdown to form melanin

Question 20

What amino acids can be glycosylated?

Answer 20

Asparagine
Serine
Threonine

Question 21

Amino acids commonly found in alpha helices

Answer 21

Alanine
Aspartic acid
Glycine
Leucine
Lysine
Serine