AMINO ACIDS AND PROTEINS

Question 1

Most abundant organic molecule in the HUMAN BODY

Answer 1

Proteins

Question 2

Enantiomer of amino acids seen in the human body

Answer 2

L-isomer

Question 3

An imino acid

Answer 3

Proline

Question 4

AA with the smallest side chain, only achiral amino acid among the 20 AAs; Used in the first step of heme synthesis

Answer 4

Glycine

Question 5

Accumulated AAs in maple syrup urine disease (MSUD)

Answer 5

Valine
Leucine
Isoleucine

Question 6

AA with the largest side chain

Answer 6

Tryptophan

Question 7

Known as the 21st AA

Answer 7

Selenocysteine

Question 8

Known as the 22nd AA; restricted only in some methanogenic archaea and bacteria

Answer 8

Pyrrolysine

Question 9

Only semi-essential AA

Answer 9

Arginine

Question 10

Sulfur-containing amino acids

Answer 10

Cysteine

Methionine

Question 11

AAs with aromatic structures (benzene rings)

Answer 11

Phenylalanine
Tyrosine
Tryptophan
Histidine

Question 12

Most basic AA

Answer 12

Arginine

Question 13

Most acidic AA

Answer 13

Aspartic acid

Question 14

First ever sequenced protein

Answer 14

Insulin

Question 15

First discovered hormone

Answer 15

Secretin

Question 16

Most common secondary structure

Answer 16

Alpha-helix

Question 17

Secondary structure seen in abnormal prion protein (PrP Sc) and Alzheimer disease histopathology

Answer 17

Beta-sheets

Question 18

AAs that can disrupt the alpha- helix structure

Answer 18

Proline

Glycine

Question 19

The only structure of proteins not affected by denaturation

Answer 19

Primary structure

Question 20

Reading of amino acid sequences

Answer 20

From N-terminus (NH3 end) to

C-terminus (COOH end)

Question 21

Most common form of hemoglobin after birth

Answer 21

Hemoglobin A1

Question 22

Location of alpha-globin genes

Answer 22

Chromosome 16

Question 23

Location of beta-globin genes

Answer 23

Chromosome 11

Question 24

Defect in sickle cell disease

Answer 24

Glutamate → Valine

at the 6th position of the beta-globin

Question 25

Defect in hemoglobin C disease

Answer 25

Glutamate → Lysine | at the 6th position of the beta-globin

Question 26

Hemoglobin Bart composition

Answer 26

4 gamma-globin

Question 27

Hemoglobin H composition

Answer 27

4 beta-globin

Question 28

Oxygen dissociation curve of myoglobin

Answer 28

Hyperbolic

Question 29

Oxygen dissociation curve of hemoglobin

Answer 29

Sigmoidal

Question 30

Most abundant protein in the body

Answer 30

Collagen

Question 31

Most common form of collagen in the body

Answer 31

Type I collagen

Question 32

Type of collagen present in early wound repair

Answer 32

Type III collagen

Question 33

Type of collagen in late wound repair

Answer 33

Type I collagen

Question 34

Defective step of collagen synthesis encountered in scurvy

Answer 34

Hydroxylation step

Question 35

Defective step of collagen synthesis encountered in osteogenesis imperfecta

Answer 35

Formation of triple helix

Question 36

Defective step of collagen synthesis encountered in Menkes disease

Answer 36

Cross-linking step (dysfunction in copper- requiring lysyl oxidase)

Question 37

Most common form of EDS

Answer 37

Hypermobility EDS

Question 38

Most serious form of EDS

Answer 38

Vascular EDS

Question 39

Most common type of collagen affected in EDS

Answer 39

Type III collagen

Question 40

Defective type of collagen in dystrophic epidermolysis bullosa (DEB)

Answer 40

Type VII collagen

Question 41

Defective structure in Marfan syndrome

Answer 41

Fibrillin

Question 42

Triad of Marfan syndrome

Answer 42

``` Skeletal changes Aortic dilatation Upward and outward dislocation of the lens (vs downward and inward dislocation of the lens in homocystinuria) ```

Question 43

Main cell that synthesizes antibodies or Igs

Answer 43

Plasma cells (derived from B cells)

Question 44

Fragment of Ig containing the antigen-binding site

Answer 44

Fab

Question 45

Fragment of Ig containing the complement-binding site and macrophage-binding site

Answer 45

Fc

Question 46

Responsible for determining the isotype of class of Ig

Answer 46

Heavy chains

Question 47

Most abundant light chain in humans

Answer 47

Kappa chain

Question 48

Proteins containing light chains and can be found in the urine of patients with multiple myeloma

Answer 48

Bence-Jones protein

Question 49

Most abundant Ig in the BODY (which includes mucous membranes)

Answer 49

IgA

Question 50

Most abundant Ig in SERUM

Answer 50

IgG > IgA > IgM > IgD, IgE

Question 51

Cleaves Ig into 3 parts

Answer 51

Papain

Question 52

Cleaves Ig into 2 parts

Answer 52

Pepsin

Question 53

Refers to the part of the ANTIGEN to which an antibody binds

Answer 53

Epitope

Question 54

Refers to the part of the ANTIBODY that binds to the epitope of the antigen

Answer 54

Paratope