You are required to draw blood from a patient and to keep it in a test tube for analysis of blood corpuscles and plasma. You are also provided with the following four types of test tubes. Which of these will you not use for the purpose

• Test tube containing calcium bicarbonate

• Chilled test tube

• Test tube containing heparin

• Test tube containing sodium hydroxide

Cattle fed with spoilt hay of sweet clover which contains dicumarol

• are healthier due to a good diet

• catch infections easily

• may suffer vitamin K deficiency and prolonged bleeding

• may suffer from beri-beri due to deficiency of vitamin B₁

Enzymes, vitamins and hormones can be classified into a single category of biological chemicals because of all of these

• enhance oxidative metabolism

• are conjugated proteins

• are exclusively synthesised in the body of a living organism as at present

• help in regulating metabolism.

Assertion: Competitive inhibitor is also called as substrate analogue.

Reason: It resembles the enzymes in structure.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

An example of competitive inhibition ofan enzyme is the inhibition of

• succinic dehydrogenase by malonic acid

• cytochrome oxidase by cyanide

• hexokinase by glucose-6-phosphate

• carbonic anhydrase by carbon dioxide

Which of the following contain $\mathrm{\beta }$-1, 4 linkage?

• Maltose

• Sucrose

• Lactose

• Fructose

97.

Which statement is true?

• Adenine has 4 nitrogen atoms.

• Cytosine has 3 nitrogen atoms

• Guanosine has 3 nitrogen atoms

• Uracil has 5 nitrogen atoms

The figure given below shows three velocity substrate concentration curves for an enzyme reaction. What do the curves a, b, and c depict respectively

• a-normal enzyme reaction,
  b-competitive inhibition,
  c-non-competitive inhibition.

• a-enzyme with an allosteric modulator added,
  b-normal enzyme activity,
  c-competitive inhibition

• a-enzyme with an allosteric stimulator,
  b-competitive inhibition added
  c-normal enzyme reaction

• a-normal enzyme reaction,
  b-non-competitive inhibitor added
  c-allosteric inhibitor added

Which one of the following statements regarding enzyme inhibition is correct?

• Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein.

• Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme

• Non-competitive inhibition ofan enzyme can be overcome by adding large amount of substrate

• None of these

In an experiment freshly hatched larvae of an insect (Khapra beetle) were reared on a basal diet (complete diet without cholesterol) with increasing amounts of cholesterol. Results obtained are shown in the graph given in the table :

The graph indicates that

• cholesterol is an essential dietary requirement of khapra beetle

• growth of khapra beetle is directly proportional to cholesterol concentration

• cholesterol concentration of 2 µg/g diet is the optimum level

• growth of khapra beetle is inhibited when cholesterol concentration exceeds 5 g/g diet