unit 2

Question 1

Explain why the structure of myoglobin makes it function well as an oxygen-storage protein, whereas the structure of hemoglobin makes it function well as an oxygen-transport protein. (use graph that you sketch in question 01 and use pO2 values in lungs and tissues)

Answer 1

Myoglobin
at pO2 = 4, O2 bind well
no cooperative binding

Hemoglobin
at pO2 = 4 ATM, releases O2
having 4 subunit promoting O2 binding

Question 2

How does BPG binding to hemoglobin decrease its affinity for oxygen? (need to include the following information to get full points: where BPG binds)

Answer 2

BPG binds the cavity between subunits

Question 3

How does BPG binding to hemoglobin decrease its affinity for oxygen? (need to include the following information to get full points: where structural changes take place during BPG binding)

Answer 3

At where T-state gets stabilized

Question 4

How does BPG binding to hemoglobin decrease its affinity for oxygen? (need to include the following information to get full points: how BPG effects O2 binding?

Answer 4

O2 binding get reduced.

Question 5

what is the effect of pH on the binding of oxygen to hemoglobin (Bohr Effect) 1.

Answer 5

H+ binds to His, protonate His in tissues due to increase in H+
O2 get release

Question 6

what is the effect of pH on the binding of oxygen to hemoglobin (Bohr Effect) 2.

Answer 6

This stabilizes T-state at tissues.
But in lungs, pH is increase R-state is prominent, binding O2

Question 7

Name the two principal models for the cooperative binding of ligands to proteins with multiple binding sites.

Answer 7

sequential
concerted

Question 8

Answer 8

Enzyme complementary to transition state

Question 9

Answer 9

No enzyme

Question 10

Answer 10

enzyme complementary to the substrate

Question 11

Cofactor or coenzyme that tightly binds or covalently linked to the enzyme is called as

Answer 11

prosthetic group

Question 12

A type of enzyme inhibition reversed by increasing the substrate concentration

Answer 12

competitive inhibition

Question 13

Stereoisomers that differ at only one chiral center

Answer 13

epimers

Question 14

A protein with multiple ligand-binding sites, such that ligand binding at one site affects ligand binding at another is called as

Answer 14

allosteric protein

Question 15

Polysaccharides that have one type of monomer units

Answer 15

Homopolysaccharide

Question 16

A region in the protein where the ligand binds is called

Answer 16

binding site

Question 17

The characteristic of an enzyme or other protein in which binding of the first molecule of a ligand changes the affinity for the second molecule

Answer 17

coorperativity

Question 18

How many substrate molecules one enzyme molecule can convert per second is known as

Answer 18

turnover number

Question 19

D-Mannose and D-galactose vary at more than one chiral center and are example of

Answer 19

diasteromers

Question 20

A simple sugar in which the carbonyl carbon atom is an aldehyde

Answer 20

aldose

Question 21

Define Km

Answer 21

affinity of substrate to the enzyme

Question 22

Define Vmax

Answer 22

maximum velocity of the enzyme

Question 23

what 2 carbohydrate monomers make up lactose

Answer 23

Galactose
Glucose

Question 24

When oxygen binds to a heme-containing protein, the two open coordination bonds of Fe 2+ are occupied by what molecules?

Answer 24

Protein (Histidine)
O2 molecule

Question 25

Which amino acid in hemoglobin is involved in coordinating iron in addition to the heme prosthetic group? a) Tyr b) Glu c) His d) Val e) Cys

Answer 25

c) His

Question 26

A Hill coefficient (nH) of 2 indicates that: a) there is positive cooperativity in ligand binding. b) there are two ligand-binding sites. c) there is negative cooperativity in ligand binding. d) there is positive cooperativity in ligand binding and there are two ligand-binding sites. e) there is negative cooperativity in ligand binding and there are two ligand-binding sites

Answer 26

a) there is positive cooperativity in ligand binding.

Question 27

Chymotrypsin catalyzes the cleavage of proteins at peptide bonds adjacent to aromatic amino acid residues by using which catalytic mechanism? a) general acid-base catalysis b) metal ion catalysis c) covalent catalysis d) both general acid-base catalysis and metal ion catalysis e) both general acid-base catalysis and covalent catalysis

Answer 27

e) both general acid-base catalysis and covalent catalysis

Question 28

Which pair is interconverted in the process of mutarotation? a) D-glucose and D-fructose b) D-glucose and D-galactose c) D-glucose and D-glucosamine d) D-glucose and L-glucose e) α-D-glucose and β-D-glucose

Answer 28

e) α-D-glucose and β-D-glucose

Question 29

Which compound is NOT a reducing sugar? a) fructose b) glucose c) glyceraldehyde d) lactose e) sucrose

Answer 29

e) sucrose

Question 30

Starch and glycogen are both polymers of: a) fructose. b) glucose1-phosphate. c) sucrose. d) α-D-glucose e) β -D-glucose

Answer 30

d) α-D-glucose

Question 31

A significant contribution to the change in hemoglobin affinity for oxygen from pH 7.2 to pH 7.6 is due to a change in the protonation state of which amino acid side chain? a) Cys b) His c) Ser d) Asp e) Lys

Answer 31

b) His

Question 32

The binding of oxygen to hemoglobin stabilizes the _____ of the protein due to interactions between _____ residues in the center of the multisubunit complex. a) R state; Thr b) R state; Glu c) R state; His d) T state; Glu e) T state; His

Answer 32

c) R state; His

Question 33

Sickle cell anemia is caused by a single mutation in the hemoglobin protein from a Glu to a Val, which results in which alteration in the hemoglobin subunits? a) more neutral charges and formation of a nucleophilic contact point b) fewer negative charges and formation of a hydrophobic contact point c) fewer positive charges and formation of a hydrophobic contact point d) more negative charges and formation of a hydrophilic contact point e) more positive charges and formation of a hydrophilic contact point

Answer 33

b) fewer negative charges and formation of a hydrophobic contact point

Question 34

Carbohydrates consist with large number of monomer units

Answer 34

Polysaccharide

Question 35

Carbohydrates with only one type of monomer units

Answer 35

Homoploysaccharides

Question 36

Carbohydrates with different types of monomer units

Answer 36

Heteropolysaccharides

Question 37

Carbohydrates with 3-10 monomer units

Answer 37

Oligosaccharides

Question 38

Carbohydrates linked to other biological molecules

Answer 38

Glycoconjugates

Question 39

Type of proteoglycan having the protein with single transmembrane domain

Answer 39

Syndecans

Question 40

Type of proteoglycan having the protein which anchored to a lipid membrane

Answer 40

Glypicans

Question 41

aterial outside the cell that consist with protecoglycans, collagen fibers, and fibrous proteins

Answer 41

Extracellular matrix -