RANDOM EXAM QUESTIONS: test your mind

Question 1

A single-based DNA gene coding changes is least likely to significantly affect the function of resulting protein:

Answer 1

silent mutations in the 3rd codon base

Question 2

Which of the following is a property of enhancer elements?
A. They do not work located downstream of the promoter
B. They could work when located long distances from the promoter
C. Upon activation, they could repress transcriptional rate.
D. They are proteins binding to DNA sequences.

Answer 2

B. They could work when located long distances from the promoter.
[DNA elements capable of elevating transcriptional efficiency of the genes they regulate regardless of their orientation and locality in the genome]

Question 3

It is considered as a transcriptional regulation control?

Answer 3

chromatin remodelling
[the dynamic modification of chromatin architecture to allow access of condensed genomic DNA to the regulatory transcription machinery proteins, and thereby control gene expression]

Question 4

It defines the specificity of hormone activity in a cell?

Answer 4

presence of a hormone receptor

Question 5

____ hormones need transport proteins

Answer 5

Lipophilic

Question 6

A vitamin that is essential for one-carbon metabolism

Answer 6

folic acid

Question 7

characteristic component of the extracellular matrix is that ______ is involved mainly in cell adhesion and signaling.

Answer 7

fibronectin

Question 8

Which is not correctly paired? 
A. IgA: found in secretions 
B. IgM: transplacental passage 
C. IgG: opsonization 
D. IgE: allergic responses

Answer 8

B. IgM: transplancental passage
[largest antibody, and it is the first antibody to appear in the response to initial exposure to an antigen]
Transplacental passage: IgG
Opsonization: IgG, IgE
[“enhanced attachment”, refers to the antibody molecules IgG and IgE, the complement proteins C3b and C4b, and other opsonins attaching antigens to phagocytes. This results in a much more efficient phagocytosis]

Question 9

general class of enzymes that join molecules by creating a new chemical bond at the expense of ATP hydrolysis

Answer 9

LIGASE

Question 10

an enzyme that catalyzes the reaction: lecithin + cholesterol -> FA cholesterol ester + lysolecithin is calssified as:

Answer 10

TRANSFERASE

Question 11

The michelis menten constant is equal to substrate concentration when:

Answer 11

initial velocity is 1/2 max

Question 12

The active form of vitamin B12 co-enzyme

Answer 12

5 - deoxyadenosylcobalamin

Question 13

In bioenergetics, the amount of energy available for the performance of useful work is termed:

Answer 13

free energy

Question 14

During biological oxidation, reduced coenzymes such as NADH and FADH2 generate energy when oxidized through the:

Answer 14

Electron Transport Chain

Question 15

The final acceptor of electrons in the respiratory chain is:

Answer 15

oxygen

Question 16

substrate level phosphorylation differs from oxidative phosphorylation in that:

Answer 16

oxidative phosphorylation synthesizes ATP via the ETC q

Question 17

___ affects the biological oxidation by diassociating mitochondrial respiration

Answer 17

2,4 dinitrophenol

Question 18

In man, glucose from dietary cellulose could not be available for energy because:

Answer 18

man inherently lack enzyme to hydrolyze cellulose

Question 19

The major pathway of glucose metabolism that exists in all cells is the

Answer 19

Emdben Meyerhof Pathway

Question 20

hexokinase differs from glucokinase in which aspect?

Answer 20

hexokinase is inhibited by glucose-6 phosphate

Question 21

The end product of glycolysis in exercising muscle and RBC’s is:

Answer 21

lactic acid

Question 22

The most important positive regulator of the committed step of glycolysis is the availability of

Answer 22

fructose 2,6 bisphosphate

Question 23

rate limiting step in the Pentose Phosphate Pathway is catalyzed by:

Answer 23

glucose-6 phosphate DEHYDROGENASE

Question 24

an enzymatic reaction that is common to both glycolysis and gluconeogenesis

Answer 24

phosphotriose isomerase