Select the option which is NOT correct with respect to enzyme action: 
Inhibitions of succinic dehydrogenase by malonate is an example of competitive inhibition. Thus it is a reversible reaction.
On increasing the substrate (succinate) concentration the effect of inhibitor is removed and Vmax remains the same.
Hence option B is correct.
Which one of the following is a non - reducing carbohydrate? 
Sucrose is classified under non reducing sugars because it does not have any free aldehyde or keto group.
Which one of the following statements is INCORRECT? [2015 RS]
Km increases but Vmax remains the same in competitive inhibition.
This is because, on slightly increasing the substrate concentration, the effect of inhibitor is removed.
Which of the following biomolecules does have phosphodiester bond ? [2015 RS]
Nucleic acids have phosphodiester bond in a nucleotide.
The enzyme that is NOT present in succus entericus is : [2015 RS]
Succus entericus is the clear to pale yellow watery secretions from the glands lining the small intestine walls. It contains hormones, digestive enzymes, mucus, and bicarbonate. It doesn't contain a nuclease enzyme.
A nuclease is an enzyme capable of cleaving the phosphodiester bonds between the nucleotide subunits of nucleic acids.
The introduction of t-DNA into plants involves: [2015 RS]
The two polypeptides of human insulin are linked together by 
Structure of Insulin:
Which of the following is required as inducer(s) for the expression of Lac operon ? 
Lac operon is an inducible operon. Lactose is the substrate for the enzyme beta-galactosidase and it also regulates switching on and off of the operon. Hence, it is termed as inducer.
The amino acid Tryptophan is the precursor for the synthesis of 
Option A: Tryptophan is a precursor to neurotransmitters serotonin and melatonin.
Option B: Thyroxine (3,5,3',5'-tetraiodothyronine) is produced by follicular cells of the thyroid gland. It is produced as the precursor thyroglobulin.
Option C: Estrogen is biosynthesized from progesterone (arrived at in two steps from cholesterol, via intermediate pregnenolone).
Option D: Cortisone is one of several end-products of a process called steroidogenesis. Cortisol is produced in the adrenal cortex of kidney.
Hence, Option A is correct.
Which one of the following statements is WRONG? 
Glycine (abbreviated as Gly or G) is the smallest of the 20 amino acids commonly found in proteins. The formula is NH2CH2COOH.
Its codons are GGU, GGC, GGA, GGG of the genetic code.
A typical fat molecule is made up of 
A typical fat molecule has one glycerol and three fatty acid molecules.
Structure of a typical fat molecule: