Railway Science (Biology-Nutrition in Animal)

DNA (Deoxyribonucleic acid) is the molecule that carries genetic information for the development and functioning of an organism. It is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The information in DNA is stored as a code made up of four chemical bases - adenine (A), guanine (G), cytosine (C), and thymine (T).

Amoeba is a microscopic single -celled organism found in pond water. Amoeba has a cell membrane, a rounded dense nucleus and many small bubble-like vacuoles (digestion of food) in its cytoplasm.
Amoeba constantly changes its shape and position. It pushes out one or more finger-like projections called pseudopodia, for movement and capture of food.

Protein - Made up of one or more long, folded chains of amino acids (each called a polypeptide). Function of Protein - Help in regenerating and creating DNA molecules and carry out complex processes.
Proteins are involved in the creation of various types of hormones (Insulin and Secretin). Antibody protein is used by the immune system to repair and heal the body from foreign bacteria. Sources of Protein - Beans, Pulses, Yogurt, Fish and seafood, Soya, Nuts and seeds, Pork.

In autotrophic tissues, Starch is gradually formed during the day through photosynthesis. At night, starch is degraded to support non -photosynthetic leaf metabolism and the export of sucrose. Example - Leaf mesophyll. Glycogen - Made up of many connected glucose molecules. The basic chemical formula of the starch molecule is (C₆H₁₀O₅)ₙ .

Heterotrophs - An organism that eats other plants or animals for energy and nutrients. Example - Dog, Fish, Human. If the consumer eats the producers, the plants, they are called primary consumers and if the animals eat other animals which in turn eat the plants (or their produce) they are called secondary consumers.

Pulse is the edible seed from a legume plant. It is also an inexpensive source of protein, vitamins, complex carbohydrates and fiber. Protein Deficiency Disease - Kwashiorkor and Marasmus. Green Leafy Vegetables - A rich source of nutrients. Apples - Source of Iron and fiber. Cereals - An excellent source of carbohydrates.

Nutrients in Milk - Calcium, Riboflavin, Phosphorus, Vitamins A and B₁₂, Potassium, Magnesium, Zinc, Iodine, lactic acid. Balanced diet contains all of the essential elements that the human body needs. The accepted average calorie requirement in India is 2400 calories per person per day in rural areas and 2100 calories per person per day in urban areas.

Sources of Vitamin C - Kiwifruit, Orange, Broccoli, Strawberry, Mango, Lemon, Papaya, Tomatoes, Potato, Pineapple. Eggs are a good source of vitamin A, D, E, B₆ , B₁₂ and vitamin K. Dates {Contain vitamins B₁₂ (thiamine), B₂ (riboflavin), Nicotinic acid (niacin) and vitamin A} - Good source of antioxidants, mainly carotenoids and phenolics.

Food energy is defined as the energy released from carbohydrates, fats, proteins, and other organic compounds. Fats have the greatest amount of food energy per mass, up to 9 kcal g⁻¹.
Most carbohydrates and proteins have approximately 4 kcal g ⁻¹ . Roughage (Fiber) doesn't give us energy. It is the part of plant-based foods (grains, fruits, vegetables, nuts, and beans) that the body can't break down.

It is required for the development, myelination and function of the central nervous system, healthy red blood cell formation and DNA synthesis. It is naturally present in foods of animal origin, including fish, meat, poultry, eggs, and dairy products.