(i) Lipids
(ii) It is a common sterol and also the parent compound for steroid hormones.
(iii) Cholesterol exists in two forms, i.e., low density cholesterol which is harmful and high density cholesterol, which is essential for various physiological processes.

The most important fact of biology systems is that all living organisms exist in a steady-state characterised by the concentration of each of the biomolecule. These biomolecules are in a metabolic flux. Any chemical or physical process moves spontaneously to equilibrium. Thus, the steady state is a non-equilibrium state.
As living organisms work continuously, they cannot afford to reach equilibrium. Hence, the living state is a non-equilibrium steady-state to be able to perform work. This is achieved by energy input. Metabolism provides a mechanism for the production of energy.
Hence, the living state and metabolism are synonymous. Without metabolism, there cannot be a living state.

The sequence of amino acids, i.e., the positional configuration in a protein which is the first amino acid, which is second and so on is called the primary structure of a protein.
The first amino acid is also called as N-terminal amino acid. The last amino acid is called the C-terminal amino acid. Yes, we can connect this information to purity or homogeneity of a protein. Based on number of amino and carboxyl groups, these can be acidic (e.g., glutamic acid), basic (lysine) and neutral (valine) amino acids.

The inhibitor competes with the substract for the active sites of enzyme molecules as it has a structure similar to the substract that allows it to combine with the active site, preventing any substract molecule from occupying that site.This reduces the rate of the reaction since, the subtract can only use the enzyme molecules that are not occupied by the inhibitor, resulting in the same quantity of product being formed at a slower rate

(i) The type of inhibition of succinic dehydrogenase by malonate is competitive inhibition
(ii) The inhibitor competes with the substract for the active sites of enzyme molecules as it has a structure similar to the substract that allows it to combine with the active site, preventing any substract molecule from occupying that site.This reduces the rate of the reaction since, the subtract can only use the enzyme molecules that are not occupied by the inhibitor, resulting in the same quantity of product being formed at a slower rate.