| I: | the left end is represented by the first amino acid and the right end is represented by the last amino acid. | 
| II: | the first amino acid is also called as C-terminal amino acid and the last amino acid is called the N-terminal amino acid. | 
| Assertion (A): | Lipids separate in the macromolecular fraction of a cell. | 
| Reason (R): | Lipids are associated with membranes in a cell. | 
| 1. | Both (A) and (R) are True but (R) does not explain (A). | 
| 2. | (A) is True but (R) is False. | 
| 3. | Both (A) and (R) are True and (R) correctly explains the (A). | 
| 4. | (A) is False but (R) is True. | 
| 1. | The substrate binds to the active site of the enzyme, fitting into the active site. | 
| 2. | The binding of the substrate induces the enzyme to alter its shape, fitting more tightly around the substrate. | 
| 3. | The active site of the enzyme, now in close proximity of the substrate breaks the chemical bonds of the substrate and the new enzyme- product complex is formed. | 
| 4. | The enzyme releases the products of the reaction and the enzyme is used up and cannot be used again. | 
| Assertion (A): | With the increase in substrate concentration, the velocity of the enzymatic reaction rises at first but ultimately reaches a maximum velocity which is not exceeded by any further rise in concentration of the substrate. | 
| Reason (R): | The enzyme molecules are fewer than the substrate molecules and after saturation of these molecules, there are no free enzyme molecules to bind with the additional substrate molecules. | 
| 1. | (A) is True but (R) is False | 
| 2. | Both (A) and (R) are True but (R) does not explain (A) | 
| 3. | (A) is False but (R) is True | 
| 4. | Both (A) and (R) are True and (R) correctly explains (A) | 
 
| 1. | is a lipid | 
| 2. | constitutes majority of a cell membrane in animal cells | 
| 3. | is a macromolecule | 
| 4. | is hydrophilic | 
| Assertion (A): | Dietary proteins are the source of essential amino acids. | 
| Reason (R): | Amino acids are organic compounds containing an amino group and an acidic group as substituents on the same carbon. | 
| 1. | Both (A) and (R) are True but the (R) does not explain (A). | 
| 2. | (A) is True but (R) is False. | 
| 3. | Both (A) and (R) are True and (R) correctly explains (A). | 
| 4. | (A) is False but (R) is True. |