Pharmaceutical Biotechnology Questions and Answers - Phase 1 Reactions

1. What is the inactive form of Codeine?
a) Codene
b) Codane
c) Morphine
d) Poppy

Answer: c
Explanation: The codeine is given to a patient on in its inactive form. Through metabolism, this inactive codeine is converted into its active form morphine.

2. What are soft drugs?
a) Drugs given to babies
b) Chemical drugs which are already found in the body
c) Nutrients which kill the gut harmful microbes
d) Anything that is not nutrients and enters the body through different routes

Answer: b
Explanation: Soft drugs are natural endogenous substances which are already present in the body. Such as neurotransmitters (dopamine, GABA, epinephrine, norepinephrine), steroids (oxytocin, oestrogen, progesterone), insulin. The body is already programmed to metabolize them and excrete out. Thus these drugs when used are rapidly inactivated.

3. Which of the following is the correct decreasing order of drug metabolism?
a) Liver > lungs > kidneys > intestine > placenta > skin > adrenals
b) Liver > lungs > kidneys > intestine > adrenals > placenta > skin
c) Liver > kidneys > lungs > intestine > placenta > adrenals > skin
d) Liver > lungs > intestine > kidneys > placenta > adrenals > skin

Answer: a
Explanation: Liver is the primary site for metabolism. Of most of the drugs. It is because it has most of the enzymes in it that are in large numbers. Metabolism by other organs is very less because they have a very low quantity of enzymes present in them. Thus the order is liver > lungs > kidneys > intestine > placenta > skin > adrenals.

4. The enzymes are divided into two categories, these are _______ and ____________
a) Acidic drug metabolizing and basic drug metabolizing
b) Present in the liver and not present in the liver
c) Microsomal and non-microsomal
d) There is no such division

Answer: c
Explanation: The enzymes are divided into 2 categories namely microsomal and non-microsomal. Microsomal enzymes catalyse the majority of the drug biotransformation reactions. The large variety of microsomal enzymes catalyse a number of oxidative, reductive and hydrolytic reactions.

5. Microsome are selective to ____________
a) Water-soluble drugs
b) Lipid soluble drugs
c) Acidic drugs
d) Basic drugs

Answer: b
Explanation: The intact Lipoidal membrane of the microsome is essential for its selectivity towards lipid soluble substrates. The lipid soluble substrate is bio transformed into water-soluble metabolite by the microsomal enzymes and thus can easily excrete out.

6. Where are non-microsomal enzymes present?
a) In the Golgi apparatus
b) Inside lysosomes
c) In the cytoplasm in soluble form
d) In oxysomes

Answer: c
Explanation: Non-microsomal enzymes include those that are present in soluble form in the cytoplasm and those attached to the mitochondria but not to the endoplasmic reticulum. These enzymes are non-specifically catalysing few oxidative reactions, the number of reductive reactions and hydrolytic reactions.

7. Following are the Phase I reactions except ____________
a) Oxidative reactions
b) Hydrolytic reactions
c) Reductive reactions
d) Sulphide reactions

Answer: d
Explanation: Phase I reactions precedes phase II reactions. These reactions are an oxidative reaction, hydrolytic reactions, and reductive reactions. Phase I reactions include introducing or removing of –OH, -COOH, -NH2 and –SH. This phase I reactions are also known as functionalization reactions

8. What are the names of the 3 protein involve in multienzyme mixed-function oxidase system, located in the endoplasmic reticulum?
a) Heme protein, flavoprotein, phosphatidylcholine
b) Heme protein, flavoprotein, retinal protein
c) Heme protein, retinal protein, phosphatidylcholine
d) Retinal protein, flavoprotein, phosphatidylcholine

Answer: a
Explanation: Heme protein helps in oxidizing the substrate, flavoprotein functions as an electron carrier and catalyses the reduction of cytochrome 450 to ferrous form, phosphatidylcholine functions to facilitate electron transfer from NADPH to cytochrome 450.

9. What is the function of Phosphatidylcholine in multienzyme mixed-function oxidase system, located in the endoplasmic reticulum?
a) Oxidising the substrate
b) Reducing the substrate
c) Facilitate electron transfer from NADPH to cytochrome 450
d) Facilitate electron transfer from cytochrome 450 to NADPH

Answer: c
Explanation: Phosphatidylcholine has choline as a head group. These are major components of the cell membrane. Phosphatidylcholine is a heat stable lipid component which functions to facilitate electron transfer from NADPH to cytochrome 450.

10. What is the function of a flavoprotein, located in the endoplasmic reticulum?
a) Oxidising the substrate
b) Reducing the cytochrome-450 to the ferrous form
c) Facilitate electron transfer from NADPH to cytochrome 450
d) Facilitate electron transfer from cytochrome 450 to NADPH

Answer: b
Explanation: Flavoprotein functions as an electron carrier and catalyses the reduction of cytochrome 450 to ferrous form by transferring an electron from NADPH. Flavoprotein in multienzyme mixed-function oxidase system.