Some Questions about Hemoglobin

Some questions about Hemoglobin:

 

Question P-02

 

The affinity of Hemoglobin for Oxygen increases when:

 

a)     a molecule of Oxygen binds to one of the Hem groups

b)     protons concentration increases

c)      the concentration of 2,3-BPG increases

d)     an acidosis is established

e)     the concentration of Carbon Dioxide increases

 

Question P-03

 

This substance, transported by Hemoglobin, promotes the relaxation of vascular walls, producing an important and potent vasodilator effect.

a)     2,3, BPG

b)     Carbon monoxide

c)      Carbon Dioxide

d)     Nitric Oxide

e)     Oxygen

 

Question P-04

 

Hemoglobin F is formed by:

 

a)     1 Hem group, two alpha peptide chains and two beta peptide chains

b)     1 Hem group, two alpha peptide chains and two gamma peptide chains

c)      2 Hem groups, two alpha peptide chains and two beta peptide chains

d)     2 Hem groups, two alpha peptide chains and two gamma peptide chains

e)     4 Hem groups, two alpha peptide chains and two beta peptide chains

f)       4 Hem groups, two alpha peptide chains and two gamma peptide chains

 

Question P-05

 

An important difference between Methemoglobin and hemoglobin is that:

 

a)     Methemoglobin has four  alpha chains

b)     Methemoglobin has four beta chains.

c)      Methemoglobin has two alpha chains and two gamma chains

d)     Methemoglobin has iron in Ferric state instead of Ferrous state

e)     Methemoglobin has cupper instead of iron.

 

 

Basic Questions about Enzymes.

 

 

Choose the best answer:

 

 

Enzyme Question E-02

 

 

Inactive precursors of some enzymes that are activated through hydrolysis reactions are called:

 

a)     allosteric enzymes

b)     apoenzymes

c)      holloenzymes

d)     prosthetic groups

e)     zymogens

 

      Answer

 

Enzyme Question E-03

 

L-amino acid dehydrogenase is an enzyme that can catalyze the oxidation of different L-amino acids. It can not catalyze the oxidation of D-amino acids or other L-compounds. Based on these characteristics we can say that this enzyme shows:

 

a)     absolute specificity over substrate

b)     allosteric regulation

c)      relative specificity over substrate

d)     specificity of action

e)     specific inhibition

 

Answer

 

Enzyme Question E-04

 

These enzymes have different structure but the same catalytic function. Frequently they are oligomers made from different polypeptide chains. These enzymes are called:

 

a)     allosteric enzymes

b)     isozymes

c)      lyases

d)     proenzymes

e)     zymogens

 

Answer

 

 

Enzyme Question E-05

 

 

The model that explain that the active site is flexible and the catalytic group(s) of the enzyme is (are) brought into proper alignment by the substrate is called

 

a)     Concerted model

b)     Induced fit model

c)      Lock and key model

d)     Michaellis Menten model

e)     Sequential model

 

 

 

Krebs Cycle Extended Matching Question

Krebs Cycle Extended Matching Questions.

 

(Another format you can expect to see in your Multiple Choice medical exams)

 

 

Options:

 

a) Aconitase

b) Alpha-ketoglutarate dehydrogenase

c) Citrate synthase

d) Fumarase

e) Isocitrate dehydrogenase

f) Malate dehydrogenase

g) Succinate dehydrogenase

h) Succinil Co A synthase

 

Lead in:

 

For each enzyme feature, select the most likely Krebs Cycle enzyme:

 

 

Stems:

 

(B-06)

This enzyme catalyzes the SLP reaction of the Krebs Cycle in which GDP is phosphorylated to GTP.

 

Answer

 

 

(B-07)

This is the enzyme of the Krebs cycle that is most similar to pyruvate dehydrogenase.

 

Answer

 

 

(B-08 )

The deficit of enzymes of the TCA cycle is rare, indicating the importance of this pathway for survival. Several cases, however, are on record in which there is a severe deficiency of the enzyme that catalyzes the interconversion between fumarate and malate.  The patient is characterized by severe neurological impairment, encephalomyopathy, and dystonia developing soon after birth. Urine contains abnormal amounts of fumarate and other metabolites of Krebs Cycle. Which of the above enzymes would be deficient?

 

Answer