Protein Structure

Question 1

The only form of protein structure not affected by denaturation?

Answer 1

Primary Structure

Question 2

States that at least for a small globular protein in its standard physiological environment, the native structure is determined only by the protein’s amino acid sequence

Answer 2

Anfinsin’s Dogma

Question 3

A paradox that arises since the native folded state of protein by a random search among all possible configurations can take an enormously long time yet proteins can fold in seconds or less.

Answer 3

Levinthal Paraxox

Question 4

True or False. Most of the amino acids are a-amino acids

Answer 4

True. It means both amino and carboxyl groups are attached to the a carbon atom.

Question 5

What amino acids has the largest side chain?

Answer 5

Tryptophan

Question 6

Identify the branched-chain amino acids whose metabolites accumulate in MSUD

Answer 6

1. Leucine
2. Isoleucine
3. Valine

Question 7

What is considered to be the 21st amino acid?

Answer 7

Selenocysteine (Sec)

Question 8

Considered the 22nd Amino Acid

Answer 8

Pyrrolysine (Pyl)

Question 9

What are the essential amino acids ?

Answer 9

1. Phenylalanine
2. Valine
3. Threonine
4. Tryptophan
5. Isoleucine
6. Methionine
7. Histidine
8. Arginine
9. Lysine

Question 10

This is the only semi-essential amino acid

Answer 10

Arginine

Question 11

Characteristic of a peptide bond

Answer 11

Has a partial double-bond character

Question 12

Angle between the alpha carbon and the nitrogen

Answer 12

Phi Angle

Question 13

Angle between the alpha carbon and the carbonyl carbon

Answer 13

Psi angle

Question 14

This terminus contains targeting signals, that targets protein to a specific organelle

Answer 14

N-terminus

Question 15

This terminus has retention signals for protein sorting , which keeps the protein in the endoplasmic reticulum

Answer 15

C-terminus

Question 16

Part of a polypeptide that consist of a free -COOH structure

Answer 16

C-terminal

Question 17

Which is the terminal ends of proteins that can be modified post translationally , most commonly by the addition of a lipid anchor that allows the protein to be inserted into a membrane without having transmembrane domain?

Answer 17

C-terminal

Question 18

What do you call the supersecondary structures produced by packing side chains from adjacent secondary structural elements close to each other?

Answer 18

Motifs

Question 19

What is the fundamental functional and three-dimensional structural units of polypeptide called?

Answer 19

Domains

Question 20

These are specialized group of proteins required for the proper folding of many species of proteins

Answer 20

Chaperones

Question 21

Porphyrins have a maximum characteristic electronic absorption spectrum around _________ nm known as the Sorek peak.

Answer 21

400nm

Question 22

Factors that cause the hemoglobin curve to shift to the right.

Answer 22

1. CO2 ⬆️
2. Acidity ⬆️ (⬇️pH)
3. 2,3-BPG ⬆️
4. Exercise ⬆️
5. Temperature ⬆️

Question 23

When blood glucose enters the erythrocytes, it glycates which amino acid?

Answer 23

Lysine : Inc glycation of hgb noted in px with dm due to inc glucose in the blood

Question 24

Hydroxylation of proline and lysine residues require which vitamin?

Answer 24

Vitamin C

Question 25

Identify the most common type of Ehlers- Danlos syndrome

Answer 25

Hypermobility, other subtypes include classical and vascular.

Question 26

This refers to the part of the antigen to which antibody binds

Answer 26

Epitope

Question 27

This refers to the part of the antigen to which an antibody binds to the epitope of the antigen

Answer 27

Paratope

Question 28

This class of enzyme cleaves substrate bonds using water (adding H+ or OH-) to the cleavage products.

Answer 28

Hydrolases

Question 29

This class of enzyme catalyzes cleavage of C-C, C-S, and certain C-N bonds

Answer 29

Lyases

Question 30

This class of enzyme catalyzes the formation of bonds between C and O, S, and N coupled to hydrolysis of high energy phosphates

Answer 30

Ligases (g for group)

Question 31

This refers to the active enzyme + nonprotein component .

Answer 31

Holoenzyme

Question 32

This refers to the enzyme without its nonprotein component

Answer 32

Apoenzyme

Question 33

This refers to the nonprotein component that is a metal ion

Answer 33

Cofactor

Question 34

This refers to the nonprotein component that is small and organic molecule

Answer 34

Coenzyme

Question 35

True or False. Coenzymes are usually derived from minerals.

Answer 35

False, coenzymes are usually derived from vitamins.

Question 36

Characteristic of a competitive inhibitor.

Answer 36

Increases apparent Km without affecting Vmax

Question 37

Identify the type of enzymes that is regulated by molecules called effectors that bind noncovalently at a site other than the active site.

Answer 37

Allosteric Enzymes

Question 38

Thyroid hormones production from thyroid glands

Answer 38

1. Thyroxine (T4): 80-90% 2. Triiodothyronine (T3): 10-20%

Question 39

Identify the endopeptidases specific of the sites of basic AAs

Answer 39

Trypsin

Question 40

Identify the endopeptidases specific at sites of neutral AAs

Answer 40

1. Chymotrypsin 2. Elastase

Question 41

Identify the ectopeptidase specific at neutral AA at C- terminus

Answer 41

Carboxypeptidase A

Question 42

Characteristic of binding of Oxygen by Hgb.

Answer 42

The O2 affinity of Hgb increases as the percentage saturation increases

Question 43

The Oxyhemoglobin dissociation curve relates the ______ of oxygen in the blood to the _____ of hemoglobin with oxygen

Answer 43

Partial pressure; Percent saturation

Question 44

Increases in CO2 levels lowers the pH of blood causing hemoglobin to release O2 to the body tissues. What is this phenomenon?

Answer 44

Bohr Effect

Question 45

Removal of O2 from hemoglobin causes increase in affinity of hemoglobin for CO2 , allowing it to be expired into the lungs. What is this phenomenon?

Answer 45

Haldane Effect

Question 46

This describes the exchange of bicarbonate and chloride across the membrane of the RBCs.

Answer 46

Chloride shift or Hamburger Effect

Question 47

Each 1g of hemoglobin can maximally bind _____ ml of O2.

Answer 47

1.34mL

Question 48

Any of these genes are mutated in Alport Syndrome

Answer 48

Type IV collagen genes (heterotrimers) 1. COL4A3 2. COL4A4 3. COL4A5

Question 49

What are the hormones secreted by the anterior pituitary?

Answer 49

1. TSH 2. FSH 3. LH 4. ACTH 5. GH 6. Prolactin (FLAG PT)

Question 50

Which has a higher O2 affinity? Adult Hgb or Fetal Hgb?

Answer 50

Fetal Hgb

Question 51

Are enzymes nutritionally essential?

Answer 51

No

Question 52

What amino acid is a major excitatory neurotransmitter?

Answer 52

Glutamate

Question 53

What amino acid is a major inhibitory neurotransmitter?

Answer 53

Glycine

Question 54

What amino acid is biosynthetic precursor to porphyrins in red blood cells ?

Answer 54

Glycine

Question 55

What amino acid is most abundant in collagen ?

Answer 55

Glycine

Question 56

What amino acid is used in lipid transport?

Answer 56

Lysine

Question 57

Aspartame is composed of what amino acids? (3)

Answer 57

Phenylalanine Methanol Aspartic acid