1. | Enzymes are denatured at high temperatures |
2. | Enzymes are mostly proteins but some are lipids also |
3. | Enzymes are highly specific. |
4. | Enzymes require optimum pH and temperature for maximum activity. |
Three of the following statements about enzymes are correct and one is wrong. Which one is wrong?
1. | Enzymes are denatured at high temperatures but in certain exceptional organisms they are effective even at temperatures 80º - 90ºC |
2. | Enzymes are highly specific |
3. | Most enzymes are proteins but some are lipids |
4. | Enzymes require optimum pH for maximal activity |
The figure given below shows the conversions of a substrate into product by an enzyme. In which one of the four options (1-4), the components of the reaction labelled as A, B, C and D are identified correctly:
Options
A | B | C | D | |
1. | Transition state |
Potential energy |
Activation energy without enzyme |
Activation energy with enzyme |
2. | Potential energy |
Transition state |
Activation energy with enzyme |
Activation energy without enzyme |
3. | Activation energy with enzyme |
Transition state |
Activation energy without enzyme |
Potential energy |
4. | Potential energy |
Transition state |
Activation energy without enzyme |
Activation energy with enzyme |
For its activity, carboxypeptidase requires:
1. Iron
2. Niacin
3. Copper
4. Zinc
Which one of the following biomolecules is correctly characterised?
1. | Palmitic acid - an unsaturated fatty acid with 18 carbon atoms |
2. | Adenylic acid - adenosine with a glucose phosphate molecule |
3. | Alanine amino acid - Contains an amino group and an acidic group anywhere in the molecule |
4. | Lecithin - a phosphorylated glyceride found in the cell membrane |
An organic substance bound to an enzyme and essential for its activity is called:
1. coenzyme
2. holoenzyme
3. apoenzyme
4. isoemzyme
Which one of the following is a fat-soluble vitamin and its related deficiency disease?
1. Ascorbic acid - Scurvy
2. Retinol - Xerophthalmia
3. Cobalamine - Beri-Beri
4. Calciferol - Pellagra
The biological organisation starts with:
1. Submicroscopic molecular level
2. Cellular level
3. Organisms level
4. Atomic level
A competitive inhibitor of succinic dehydrogenase is:
1. | malonate | 2. | oxaloacetate |
3. | α-ketoglutarate | 4. | malate |