Structure Of AA and Proteins

Question 1

What is the only achiral amino acid among the 20 amino acids?

Answer 1

Glycine

Question 2

What is the smallest side chain amino acid? Used in the 1st step of heme synthesis

Answer 2

Glycine

Question 3

What is the imino acid found in the human body?

Answer 3

Proline

Question 4

What amino acid is known as the 21st amino acid?

Answer 4

Selenocysteine

Question 5

What amino acid is known as the 22nd amino acid?

Answer 5

Pyrrolysine

Restricted only in some methanogenic archaea and bacteria.

Question 6

What amino acids accumulate in maple syrup urine disease (MSUD)?

Answer 6

Leucine, Isoleucine, and Valine

Question 7

What are sulfur-containing amino acids?

Answer 7

Cysteine and Methionine

Question 8

What amino acids have aromatic structures?

Answer 8

Phenylalanine, Tyrosine, and Tryptophan

Question 9

Enantiomer of amino acids seen in the human body

Answer 9

L-amino acids

Question 10

What is the amino acid with the largest side chain?

Answer 10

Tryptophan

Question 11

What is the only semi-essential amino acid?

Answer 11

Arginine

Question 12

Most abundant organic molecule in the Human Body

Answer 12

Proteins

Question 13

Most basic AA

Answer 13

Arginine

Question 14

Most acidic AA

Answer 14

Aspartic acid

Question 15

First ever sequenced protein

Answer 15

Insulin

Question 16

First discovered hormone

Answer 16

Secretin

Question 17

Most common secondary structure

Answer 17

Alpha-helix

Question 18

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

Answer 18

Beta-sheets

Question 19

AAs that can disrupt the alpha-helix structure

Answer 19

Proline, Glycine

Question 20

The only structure of proteins not affected by denaturation

Answer 20

Primary structure

Question 21

Reading of amino acid sequences; Order of amino acid sequence synthesis

Answer 21

From N-terminus (NH3 end) to C-terminus (COOH end)

Question 22

Amino acid terminus containing targeting signals

Answer 22

N-terminus

Question 23

Amino acid terminus containing retention signals

Answer 23

C-terminus

Question 24

Amino acid terminus allowing protein to be inserted into a membrane without having a transmembrane domain

Answer 24

C-terminus

Question 25

Number of pyrrole rings in a porphyrin

Answer 25

Four

Question 26

Structure of pyrrole rings

Answer 26

Aromatic structure

Question 27

Bridge formed between pyrrole rings in a porphyrin

Answer 27

Methenyl or methyne bridges

Question 28

Maximum absorption spectrum of porphyrins

Answer 28

400 nm (known as the Soret peak)

Question 29

Heme is a metalloporphyrin containing this metal

Answer 29

Iron

Question 30

Amino acid serving as the biosynthetic precursor to porphyrins

Answer 30

Glycine

Question 31

Most common form of hemoglobin after birth

Answer 31

Hemoglobin A1

Question 32

Location of alpha-globin genes

Answer 32

Chromosome 16

Question 33

Location of beta-globin genes

Answer 33

Chromosome 11

Question 34

Defect in sickle cell disease

Answer 34

Glutamate → Valine at the 6th position of the beta-globin

Question 35

Defect in hemoglobin C disease

Answer 35

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

Question 36

Hemoglobin Bart composition

Answer 36

4 gamma-globin

Question 37

Hemoglobin H composition

Answer 37

4 beta-globin

Question 38

Oxygen dissociation curve of myoglobin

Answer 38

Hyperbolic

Question 39

Oxygen dissociation curve of hemoglobin

Answer 39

Sigmoidal

Question 40

Most abundant protein in the body

Answer 40

Collagen

Question 41

Most common form of collagen in the body

Answer 41

Type I collagen

Question 42

Type of collagen present in early wound repair

Answer 42

Type III collagen

Question 43

Type of collagen in late wound repair

Answer 43

Type I collagen

Question 44

Defective step of collagen synthesis encountered in scurvy

Answer 44

Hydroxylation step

Question 45

Defective step of collagen synthesis encountered in osteogenesis imperfecta

Answer 45

Formation of triple helix

Question 46

Defective step of collagen synthesis encountered in Menkes disease

Answer 46

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

Question 47

Most common form of Ehlers-Danlos syndrome (EDS)

Answer 47

Hypermobility EDS

Question 48

Most serious form of EDS

Answer 48

Vascular EDS

Question 49

Most common type of collagen affected in EDS

Answer 49

Type III collagen

Question 50

Defective type of collagen in dystrophic epidermolysis bullosa (DEB)

Answer 50

Type VII collagen

Question 51

Defective structure in Marfan syndrome

Answer 51

Fibrillin

Question 52

Triad of Marfan syndrome

Answer 52

Skeletal changes, aortic dilatation, upward and outward dislocation of the lens

Question 53

Main cell that synthesizes antibodies or Igs

Answer 53

Plasma cells (derived from B cells)

Question 54

Fragment of Ig containing the antigen-binding site

Answer 54

Fab

Question 55

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

Answer 55

Fc

Question 56

Responsible for determining the isotype of class of Ig

Answer 56

Heavy chains

Question 57

Most abundant light chain in humans

Answer 57

Kappa chain

Question 58

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

Answer 58

Bence-Jones protein

Question 59

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

Answer 59

IgA

Question 60

Most abundant Ig in SERUM

Answer 60

IgG

Question 61

Cleaves Ig into 3 parts

Answer 61

Papain

Question 62

Cleaves Ig into 2 parts

Answer 62

Pepsin

Question 63

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

Answer 63

Epitope

Question 64

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

Answer 64

Paratope

Question 65

Order of abundance of Ig in serum

Answer 65

IgG > IgA > IgM > IgD > IgE