Railway Science (Biology-Nutrition in Animal)

Vitamin was discovered by Casimir Funk. Types of Vitamin - Fat soluble (A, D, E, K) and Water soluble (B, C). Vitamin A : Source - Nuts, Eggs, Fish, Liver, Beet Greens, Green leafy vegetables; Deficiency Disease - Dry Skin, Dry Eyes, Night Blindness, Infertility.
Source of Vitamin C (Ascorbic acid) - Fresh fruits, black currant, broccoli, goat milk. Source of Vitamin D (Calciferol) - Fish, egg, liver, beef, cod, chicken breast. Source of Vitamin B (Thiamine) - Fresh fruits, potatoes, sweet potatoes, peas, corn, cashew nuts, wheat, milk, black beans.

Vitamin C (ascorbic acid) is a water-soluble vitamin that plays a crucial role in various bodily and immune functions.

Saprotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed organic matter. Example - fungi and soil bacteria.

Thyroid cells absorb iodine from food and convert it into thyroid hormone {thyroxine (T4) and triiodothyronine (T3)} which is important for metabolism in the human body. Iron deficiency - Anemia. Zinc deficiency - Skin disease and eczema. Calcium deficiency - Soft bones (osteomalacia).

Vitamin B₁₂ (water-soluble vitamin) - Mainly found in animal-based foods such as meat, fish, eggs and dairy products. Vitamins are substances that our bodies need to develop and function normally.
Vitamins classified into two categories : Fat-soluble vitamins - Vitamin A (Retinol), Vitamin D (Calciferol), Vitamin E (Tocopherol), Vitamin K (Phylloquinone).
Water-soluble vitamins - Vitamin C (Ascorbic Acid), Vitamin B₁ (Thiamine), Vitamin B₂ (Riboflavin), Vitamin B₃ (Niacin), Vitamin B₅ (Pantothenic Acid), Vitamin B₆ (Pyridoxine), Vitamin B₇ (Biotin), Vitamin B₉ (Folate or Folic Acid), vitamin B₁₂ (cyanocobalamin).

Saprophytic nutrition (Example – Mucor, yeast). Autotrophic nutrition - A form of self-nutrition performed by organisms using inorganic materials. Heterotrophic nutrition - A mode of nutrition in which organisms depend upon other organisms for food to survive.

Carbohydrates - They are broken down into glucose, which is used as a primary source of energy by the body. Glycogen - Excess glucose is converted into glycogen and stored in the liver and muscles.
This glycogen can be later broken down into glucose when energy is needed. Vitamins - Essential organic compounds that are required in small amounts for various biochemical processes and functions of the body.
Lipid - That is primarily composed of carbon, hydrogen, and oxygen atoms. They are insoluble in water but soluble in organic solvents like ethanol or chloroform.

White colour of milk due to presence of Casein. Cow's milk consists of around 80% casein protein. Meat - source of Protein, Fat, Vitamin – B₂ . Carrot, Tomatoes, Chillies are red in colour due to the presence of a pigment called Lycopene. Soybean meal is the most important protein source used to feed farm animals.

Proteins are very complex molecules involved in some chemical processes that are important for life. Protein is made of small units of amino acids which help in metabolism, communication, and movement in our body.
Sources of proteins are milk, cheese, pulses, peanuts, fish, meat, etc. Proteins can be classified into two types on the basis of their molecular shape.
Fibrous proteins (keratin and myosin) and Globular proteins (Insulin and albumins). The secondary or tertiary structure of proteins get disturbed on change of pH or temperature and they are not able to perform their functions. This is called denaturation of proteins.

Each gram of fat supplies the body with about 9 calories, more than twice that supplied by proteins or carbohydrates. Fat soluble vitamins are A, D, E and K.