Why are vitamin A and vitamin C essential to us ? Give their important sources.
The deficiency of vitamin A leads to xerophthalmia (hardening of the cornea of the eye) and night blindness. The deficiency of vitamin C leads to scurvy (bleeding gums).
The sources of vitamin A are fish liver oil, carrots, butter, and milk. The sources of vitamin C are citrus fruits, amla, and green leafy vegetables.
The particles in the nucleus of the cell, responsible for heredity, are called chromosomes which are made up of proteins and another type of biomolecules called nucleic acids. These are mainly of two types, DNA and RNA. Nucleic acids on hydrolysis yield a pentose sugar, phosphoric acid and nitrogen containing heterocyclic compound. Nucleic acids have a very diverse set of functions, such as cell creation, the storage and processing of genetic information, protein synthesis and the generation of energy cells. Although their functions may differ, the structure of DNA and RNA are very similar, with only a few fundamental differences in their molecular make-up. Based on the above information, answer the following questions: (a) Write two functions of DNA.
Vitamins are natural and essential nutrients. In the growth and development of the human body it plays an important role. For proper growth, strong bones and good development needs the right quantity of vitamins in our body. These vitamins are organic substances that work in groups for the normal and smooth functioning of our body cells.
There are two main types of vitamins.
Fat-soluble vitamins are stored in the fat cells. These vitamins require fat in order to be absorbed. Vitamin A, D, E and K are fat-soluble vitamins.
Water-soluble vitamins are not stored in our body because its excess gets excrete through the urine. Therefore, these vitamins need to be replenished constantly. Vitamin B and C are water-soluble vitamins.