Question

Write definitions.
a. Nutrition
b. Nutrients
c. Proteins
d. Cellular respiration
e. Aerobic respiration
f. Glycolysis

Answer 1

a. Nutrition: The process by which organisms take up nutrients and utilise these nutrients for various biological activities is called nutrition. Nutrition can be categorised as autotrophic or heterotrophic. Autotrophic nutrition refers to the process by which organisms synthesise their own food from inorganic raw materials, for example, green plants and some bacteria.
In heterotrophic nutrition, the organisms are unable to use light energy for the synthesis of food and are dependant on other organisms to fulfil their energy requirements.

b. Nutrients: Nutrient is a substance available in food that helps us to stay healthy. The main nutrients available in food are carbohydrates, fats, proteins, vitamins, minerals and roughage.

c. Proteins: Proteins are a type of biomolecules which are made up of amino acids. A protein is made up of several amino acids which are linked together by peptide bonds. They play various roles like help in body building, repairing worn out cells and keeping us healthy.

d. Cellular respiration: ​Cellular respiration is a process in which respiratory substrates such as starch, glucose, fats and proteins are broken down to release energy. This energy is then trapped for the synthesis of ATP to release CO₂.

e. Aerobic respiration: Cellular respiration occurs by two processes i.e. aerobic and anaerobic respiration. The process by which the breakdown of carbohydrates occurs in the presence of oxygen resulting in the release of energy in the form of ATP is called aerobic​ respiration.​

f. Glycolysis is the first step in respiration. In this step, six-carbon glucose is broken down into a three-carbon molecule called pyruvate. This does not require oxygen. One glucose molecule produces 2 pyruvate molecules.​