Test Yourself 13.2 (PROTEINS)
- No. i. Which elements are found in proteins?
Answer. Proteins consist of carbon, hydrogen, oxygen, nitrogen and sulphur elements.
- No. ii. How amino acids are bonded with each other?
Answer. The amino acids link through peptide linkage. Peptide linkage (bond) is formed by the elimination of water molecule between j the amino group of one amino acid and carboxyl acid group of another amino acid. Such as:
H2N-CH-COOH + HNH-CH-COOH H20 H2N – CH-C — NH- -CH-COOH |
R R R R
(Dehydration) Peptide linkage
- No. iii. Give the general formula of amino acid.
Answer. The general formula of amino acid is
(side chain)r-ch—COOH (carboxylic group)
NH2 (amino group)
It is a compound that consists of amino acid as well as carboxyl group.
- No. iv. What do you mean by non-essential amino acids?
Answer. The amino acids which are synthesized by human body are called non-essential amino acids. In our body 20 amino acids are present. Ten out of twenty amino acids are non-essential amino acids.
Test Yourself 13.3 (LIPIDS)
- No. i. What is difference between ghee and oil?
Answer. Oils exist in liquid form at room temperature. They are triglycerides off unsaturated fatty acids. While ghee exists in solid form at room temperature. They are triglycerides of saturated fatty acids.
- No. ii. Give the characteristics of fats.
Answer. They are insoluble in water but soluble in organic solvents. The fat stored in the body is poor conductor of heat and electricity.
- No. iii. Give the sources and uses of animal fats.
Answer. Animal fats are found in adipose tissue cells. Animals secrete milk from which butter and ghee are obtained. Butter and ghee are used for cooking and frying of food, for preparing bakery products and sweets. Animal fats are used in soap industry.
Marine animals like salmon and whales are also a source of oils. These oils are used as medicines e.g. cod liver oil.