Railway Science (Biology – Digestive System)

Liver is the largest gland of the body weighing about 1.2 to 1.5 kg in an adult human. It is situated in the abdominal cavity, just below the diaphragm and has two lobes.

In plants, carbohydrates are stored as a form of Glucose that is mainly formed by the process of Photosynthesis. Some plants like Carrots, Beets etc. store it inside their interior parts of their body like Root, Stems etc. On the other hand, some plants also store carbohydrates as a form of Starch (Potatoes).
Fatty acid - An important component of lipids in plants, animals and microorganisms. Amino acids are molecules used by all living things to make proteins. Fats are important macronutrients.

It is a substance which neutralizes excess acid in the stomach. Common Antacid - Milk of magnesia (Magnesium hydroxide, Mg(OH)₂ , pH - 10.5). Antihistamines - Used to relieve symptoms of allergies, such as hay fever, hives, conjunctivitis and reactions to insect bites or stings.
Antibiotic - A medicine which is used for destroying bacteria and curing infections. Sulfa drugs are used to treat urinary tract infections (UTIs), inflammatory bowel disease, vaginal, and eye infections.

It has a comparatively longer intestine than tiger, Dog and Fox because it is a herbivorous animal. Herbivorous animals are organisms that primarily consume plant matter as their main source of nutrition. Examples - Cows, horses, rabbits, deer, elephants, and many species of insects.
Carnivorous animals are organisms that primarily consume meat or the flesh of other animals as their main source of nutrition. Examples - Lions, tigers, wolves, crocodiles, and eagles.

It is a polysaccharide compound and used by the human body for food storage. It is stored within the muscles and liver. The glycogen gets converted into energy when in need by the body.
The human body uses amino acids to make proteins. Pyruvic acid, the simplest α-keto acid, plays a central role in sugar metabolism.
It is the product of glycolysis, the anaerobic decomposition of glucose. Glucose is a type of sugar that is used by the body to produce energy.

Chemical energy is energy stored by molecules in the form of chemical bonds; Released in the form of heat and includes thermal, mechanical, and kinetic energies; Example - Batteries, Photosynthesis, Biomass, Coal.
Kinetic energy - The energy an object has because of its motion; Example - A soaring baseball, a crumb falling from a table.
Thermal Energy - The energy inside a body due to motion, vibration of particles, molecules inside it; Example - Geothermal Energy, Melting ice. Electrical Energy is caused by the flow of charge or electrons; Example - Lightning, batteries.

Carbohydrates break into glucose, fructose by the enzyme amylase. Proteins converted into amino acids by proteases. Fats converted into fatty acids and glycerol by lipase enzyme. The digestion starts with the mouth.
Absorption of water and electrolytes takes place in the Large Intestine. The pharynx is a common passageway for food, air, and water from the nasal cavity and oral cavity.