Q-181. Regarding proteoglycans false is
a) Chondroitin sulfate is a proteoglycan
b) They hold less amount of water
c) They are made up of sugar and amino acids
d) They carry charge
Answer: They hold less amount of water
Explanation:
Proteoglycans are glycosylated proteins which have covalently attached highly anionic glycosaminoglycans.
The major biological function of proteoglycans derives from the physicochemical characteristics of the glycosaminoglycan component of the molecule, which provides hydration and swelling pressure to the tissue enabling it to withstand compressional forces.
Q-182. Protein purification and separation can be done by all except
a) Chromatography
b) Centrifugation
c) Electrophoresis
d) Densitometry
Answer: Densitometry
Explanation:
Protein purification and separation can be done by:
Chromatography
Centrifugation
Electrophoresis
Important point:
Densitometry may be used as a method to quantitate protein in tissue.
Q-183. Study of multiplication of proteins in disease process is called
a) Proteomics
b) Genomics
c) Glycomics
d) Nucleomics
Answer: Proteomics
Explanation:
Proteomics is a rapidly growing field of molecular biology and the large-scale study of proteins, particularly their structures and functions in biological processes like disease.
Q-184. Protein that precipitates on heating to 45 degree C and re-dissolves on boiling is
a) Bence Jones protein
b) Gamma globulin
c) Albumin
d) Myosin
Answer: Bence Jones protein
Explanation:
Bence Jones protein can be identified in the urine by its characteristics property of coagulation when heated to 50 degree C but re-dissolving on 70 degree C.
Q-185. Northern blot is used for the separation of
a) m-RNA
b) DNA
c) Protein
d) Protein DNA interaction
Answer: m-RNA
Explanation:
Blot transfer techniques:
Southern blot: DNA
Northern blot: RNA
Western Blot: Protein
South western blot: Protein-DNA interactions
Q-186. Regarding cytosolic eukaryotic gene expression false is
a) Capping helps in attachment of mRNA to 40S ribosome
b) N-formyl-methionine-tRNA will be the first t – RNA to come into action
c) EF-2 shifts between GDP & GTP
d) Releasing factor releases the polypeptide chain from the P site
Answer: N-formyl-methionine-tRNA will be the first t – RNA to come into action
Explanation:
In eukaryotic cells all polypeptides synthesized begin with a methionine residue rather than formyl methionine residue as in prokaryotes.
Q-187. CAP in lac Operon is an example of
a) Positive regulator
b) Negative regulator
c) Constitutive expression
d) Attenuation
Answer: Positive regulator
Explanation:
Regulatory proteins in Lac Operon:
CAP (Catabolite gene activator protein)-Positive regulator
Lac I gene or repressor protein-Negative regulator
Q-188. C terminal end of androgen receptor is concerned with
a) Ligand binding
b) Increasing biological half life
c) Increasing the affinity of receptor to DNA
d) Increasing the level of transcription
Answer: Ligand binding
Explanation:
A short C-terminal end is present at the end of the human androgen receptor similar to that of other steroid receptors.
This is highly conserved and critical for ligand binding.
Q-189. All of the following occur in mitochondria except
a) Citric acid cycle (Kreb’s cycle)
b) Glycogenolysis
c) Fatty acid oxidation
d) Electron transport chain
Answer: Glycogenolysis
Explanation:
Metabolic pathways occurring in cytosol:
Glycolysis
Glycogenesis
Glycogenolysis
HMT shunt
Cholesterol synthesis
Bile acid/ salt synthesis
Q-190. Regarding HMP shunt all of the following true except
a) Occurs in the cytosol
b) No ATP is produced in the cycle
c) It is active in adipose tissue, liver and gonads
d) The oxidative phase generates NADPH and the non oxidative phase generates pyruvate
Answer: The oxidative phase generates NADPH and the non oxidative phase generates pyruvate
Explanation:
HMP shunt:
Occurs in the cytosol
Occurs primarily in tissues active in reductive biosynthesis such as liver, adipose, gonads, adrenal cortex, RBCs
The oxidative phase generates NADPH.
The non oxidative phase generates ribose 5 phosphate that is required for nucleic acid synthesis.