Molecules that resemble fats but contain phosphate functional groups are called: a. steroids. b. polypeptides. c. phospholipids. d. nucleic acid.

Phospholipids. (Ans. C)

Explanation:

Phospholipids are known as lipid molecules which containing waxes, fats, and some vitamins. Each molecule of phospholipid is made up of a phosphate group head, two fatty acids tails and a glycerol molecule. Phospholipid is main component of the cell membrane.

Fatty acid tails are made up of carbon and hydrogen where phosphate group head is made up of phosphorus molecule attached with four oxygen molecules. Glycerol is helping them to attached with each other.

Some function of phospholipids are:

1) Phospholipid is selectively permeable means semipermeable in nature.

2) Molecules which are dissolved in water can not pass through the membrane and molecules which are dissolved in fat can pass through the membrane.

3) Oxygen, urea, carbon dioxide and some molecules can easily pass through the cell membrane.

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.