Vitamins are the organic compounds required in the diet in small amounts to perform specific biological functions for normal maintenance of optimum growth and health of the organism. Vitamins are classified into two groups depending on their solubility in water or fat. Vitamins which are soluble in fat and oils but insoluble in water are fat-soluble vitamins. Fat-soluble vitamins are vitamins A, D, E and K. Fat-soluble vitamins are stored in the liver and adipose tissues. Vitamins of B group and vitamin C are soluble in water and are known as water-soluble vitamins. Water-soluble vitamins must be supplied regularly in the diet because they are readily excreted in urine and cannot be stored (except vitamin B₁₂) in our body. Plants can synthesize all vitamins whereas only a few vitamins like vitamin K, vitamin A from carotene, and some members of the vitamin B complex are synthesized in the human body. Vitamins catalyze biological reactions in very low concentrations. Multiple deficiencies caused by a lack of more than one vitamin are called avitaminosis.

Chemically digestion is

hydrolysis

The correct answer is option 2. hydrolysis.

Let us delve into why hydrolysis is the correct term for describing chemical digestion:

Digestion is the process by which food is broken down into simpler molecules that can be absorbed and utilized by the body. This process involves both physical and chemical changes. Chemically, digestion focuses on the breakdown of macromolecules (like proteins, carbohydrates, and lipids) into their smaller, absorbable units through enzymatic action.

Chemical Hydrolysis in Digestion:

Hydrolysis: This is a type of chemical reaction in which water is used to break chemical bonds. In the context of digestion, hydrolysis involves enzymes catalyzing the reaction where water is used to cleave complex molecules into simpler components.

Proteins are broken down into amino acids by proteases (such as pepsin and trypsin). Carbohydrates are broken down into monosaccharides like glucose by enzymes such as amylase. Lipids are broken down into fatty acids and glycerol by lipases.

This hydrolytic process is crucial because it transforms food into molecules small enough to be absorbed through the intestinal lining and used by the body.

Comparison with Other Terms:

Hydrogenation: This chemical process involves adding hydrogen to molecules, typically used in industrial settings to convert unsaturated fats to saturated fats. It is not related to digestion.

Anabolism: This refers to metabolic pathways that build complex molecules from simpler ones, often consuming energy. Anabolism is not involved in the breakdown of food but rather in building and repairing body tissues.

Dehydrogenation: This involves the removal of hydrogen from molecules, which is not the primary process in digestion. Instead, it is more relevant in certain biochemical reactions and processes like respiration.

Summary:

Hydrolysis is the chemical reaction used in digestion to break down food molecules into simpler, absorbable units. Hydrogenation, anabolism, and dehydrogenation are not processes involved in the digestion of food.

Thus, hydrolysis accurately describes the chemical aspect of digestion, making it the correct choice.