MDS PREP
Glycolysis occurs in:
1. Cytoplasm
2. Mitochondrion
3. Both In cytoplasm and mitochondria
4. Only in presence of O2
Biochemistry
Answer: 1
Glycolysis is a metabolic process that occurs in the cytoplasm of the cell.
The process is central to the conversion of glucose into energy in the form of
adenosine triphosphate (ATP) and is a fundamental part of cellular respiration.
1. Cytoplasm: Glycolysis takes place in the cytoplasm of the cell. The cytoplasm
is the fluid-filled space between the cell membrane and the nucleus (and other
organelles in eukaryotes) where various metabolic reactions occur. This process
involves a series of enzymatic reactions that break down one molecule of glucose
into two molecules of pyruvate, yielding two net molecules of ATP and two
molecules of NADH (a reduced form of nicotinamide adenine dinucleotide) along
with some other byproducts.
2. Mitochondrion: Although glycolysis does not occur in the mitochondrion, the
mitochondrion plays a crucial role in the subsequent stages of glucose
metabolism. After glycolysis, the pyruvate molecules produced in the cytoplasm
can be transported into the mitochondria, where they are further processed in
the citric acid cycle (also known as the Krebs cycle or TCA cycle) and the
electron transport chain to produce more ATP.
Epinephrine causes increased blood glucose level due to:
1. Increased glycogenolysis in liver and muscle
2. Activation of phosphorylase
3. Inhibition of glycogen synthesis in liver
4. All of the above
Biochemistry
Answer: 4
Epinephrine causes increased blood glucose level due to:
1. Increased glycogenolysis in liver and muscle
2. Activation of phosphorylase
3. Inhibition of glycogen synthesis in liver
The essential. sulphur containing amino acid is:
1. Methionine 2. Cystetne
3. Cystine 4. Valine
Biochemistry
Answer: 1
Methionine is sulphur containing AminoAcid
A vitamin B12 deficiency may affect heme synthesis by reducing the concentration of which of the following? Choose the one best answer.
1) Acetyl-CoA
2) Succinyl-CoA
3) Glycine
4) Alanine
Biochemistry Answer: 2
Vitamin B12 participates in two reactions in the body-conversion of homocysteine to methionine and conversion ofmethylmalonyl-CoA to succinyl-CoA.
Methylmalonyl-CoA is produced via various amino acid degradation pathways, and from oddcarbon chain fatty acid oxidation. In the absence of B12, succinyl-CoA would only be produced as an intermediate of the TCA cycle, and if it were removed from the cycle for heme synthesis, energy production may suffer.
Glycine is usually obtained from the diet, although in a B12 deficiency a functional folate deficiency may also develop, leading to an inhibition of serine hydroxymethyltransferase, the enzyme that converts serine to glycine, and requires free tetrahydrofolate.
Succinyl-CoA and glycine are the precursors for heme synthesis. A B12 deficiency would not inhibit the production of acetyl-CoA, succinate, or alanine.
Aromatic amino acid is:
1. Tyrosine 2. Histidine
3. Arginine 4. Lysine
Biochemistry
Answer: 1
Tyrosine is Aromatic amino acid
The lipids associated with very low density lipoprotein
1.����� are usually linked covalently to apoproteins.
2.����� belong primarily to the phosphatidylcholine class.
3.����� incorporate fatty acids that are synthesized in the liver.
4.����� reflect, in general, the types of lipids found in the diet.
Biochemistry
Answer: 3
VLDL is a lipoprotein particle synthesized in the liver and secreted into the bloodstream to transport endogenously synthesized triglycerides and cholesterol to peripheral tissues. The triglycerides in VLDL are derived from fatty acids synthesized in the liver, and the cholesterol is derived from both dietary sources and de novo synthesis in the liver. They are not usually linked covalently to apoproteins (Answer 1), nor do they primarily consist of phosphatidylcholine (Answer 2). While the types of lipids found in the diet (Answer 4) can influence the liver's synthesis of VLDL, the statement does not accurately describe the direct composition of VLDL.
Glycine is a:
1. Glycogenic amino acid, only
2. Ketogenic only
3. Glucogenic and ketogenic
4. Since It Is optically inactive therefore none of the above
Biochemistry
Answer: 1
Glycine is a Glycogenic amino acid, only
Site of �-oxidation of fatty acid Is:
1. Cytoplasm
2. Mitochondria
3. Both cytoplasm and mitochondria
4. Lysosomes
Biochemistry
Answer: 2
�-oxidation of fatty acid occursin Mitochondria