Proteins

Question 1

Non polar aliphatic

Answer 1

Glycine, Alanine, Proline

Question 2

Non polar aliphatic (branched chain)

Answer 2

Valine, Leucine, Isoleucine

Question 3

Aromatic

Answer 3

Phenylalanine (most hydrophobic), Tyrosine, Tryptophan

Question 4

Polar, uncharged

Answer 4

Asparagine, Glutamine, Serine (forms as of most enzymes) Threonine

Question 5

Sulfur-containing

Answer 5

Methionine, Cysteine

Question 6

Charged- Negative

Answer 6

Aspartate, Glutamate

Question 7

Charged-Positive

Answer 7

Arginine, Lysine, Histidine

Histones have lysine and arginine aa which interact with DNA

Question 8

Which aa have ionising groups

Answer 8

Aspartate, Glutamate, Arginine, Lysine, Tyrosine, Cystiene

Question 9

Quaternary structure

Answer 9

Arrangement of more than one polypeptide in a multi-subunit oligomeric protein

Question 10

Secondary structure

Answer 10

Fitting as many atoms as possible into a small space

Question 11

Myoglobin

Answer 11

Stores O2 in muscle
Typical water soluble globular protein
Secondary structure: 75% alpha helical (8 chains in total)
a globin, b globin

Question 12

Hb

Answer 12

Allosteric protein
Adult Hb = HbA = a2b2
Tetramer organised as a pair of dimers
all 4 sub-units mostly alpha helical
Each sub-unit has a heme group (4 O2 per group)

Question 13

Fibrous protein: Collagen

Answer 13

Major protein in vertebrate CT (25-35% total p in mammals)
Diverse forms: tendons, skin
Triple stranded: Tropocollagen molecule (H-bonds between chains)
Multiple repeats of Gly X/Y (x= proline) (Y=hydrocyproline)
3LH helical chains coiled around each other in RH supercoil
X-linked: Lys-Lys or Lys derivative, accumulation makes collagen LESS elastic (skin changes, snapping of bones with age)

Question 14

Biomedical applications of Enzymes

Answer 14

Drug metabolism

Lab reagents

Question 15

Isozymes

Answer 15

Tissue specific physically distinct forms of a given enzyme