Water attracting molecules are called hydrophilic. Water repelling molecules are called hydrophobic. Amino acids simultaneously carry positive and negative charges. Such substances are called zwitter ions. Lipids are compounds of C, H, O but the ratio of H and O is more than 2 : 1, that is, the ratio of oxygen is lesser than carbohydrates. Lipids are insoluble in water but soluble in non-polar solvents such as benzene, chloroform etc. The most common lipid found in a cell is phospholipid. It contains a hydrophilic (polar) head and a hydrophobic (non- polar tail).

Correct Option: B

Water attracting molecules are called hydrophilic. Water repelling molecules are called hydrophobic. Amino acids simultaneously carry positive and negative charges. Such substances are called zwitter ions. Lipids are compounds of C, H, O but the ratio of H and O is more than 2 : 1, that is, the ratio of oxygen is lesser than carbohydrates. Lipids are insoluble in water but soluble in non-polar solvents such as benzene, chloroform etc. The most common lipid found in a cell is phospholipid. It contains a hydrophilic (polar) head and a hydrophobic (non- polar tail).

A saturated or unsaturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached forms phosphoglycerides. Phosphoglycerides are major structural components of cell membranes. They are, therefore, called membrane lipids. Lecithin is one such example.

Correct Option: B

A saturated or unsaturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached forms phosphoglycerides. Phosphoglycerides are major structural components of cell membranes. They are, therefore, called membrane lipids. Lecithin is one such example.

Fat molecules are made of atoms of carbon, hydrogen and oxygen. The hydrogen and oxygen atoms binds to the carbon, as pictorially depicted. A typical fat molecule has one glycerol and three fatty acid molecules.

Correct Option: B

Fat molecules are made of atoms of carbon, hydrogen and oxygen. The hydrogen and oxygen atoms binds to the carbon, as pictorially depicted. A typical fat molecule has one glycerol and three fatty acid molecules.

An amino acid molecule consists of a central carbon bonded to an amino group (–NH₂), a carboxylic group (–COOH), a hydrogen atom and a carbon chain or ring on its sides.

Correct Option: D

An amino acid molecule consists of a central carbon bonded to an amino group (–NH₂), a carboxylic group (–COOH), a hydrogen atom and a carbon chain or ring on its sides.

In the cytoplasm protein synthesis is restricted to the ribosomes. Mitochondria being a semiautonomous organelle, has its own genetic machinery to synthesize its proteins.

Correct Option: C

In the cytoplasm protein synthesis is restricted to the ribosomes. Mitochondria being a semiautonomous organelle, has its own genetic machinery to synthesize its proteins.