Railway Science (Biology – Respiratory System)

Hemoglobin - Iron-containing respiratory pigment in humans and is present in the red blood cells. The respiratory pigment - It helps in carrying oxygen from the lungs to all parts of the body.
Melanin - A substance in the body that produces hair, eye and skin pigmentation. Pheomelanin - A reddish-yellow sulfur-containing melanin pigment formed in the presence of cysteine.
Eumelanin - An inert pigment capable of efficiently absorbing UV photons as they enter the epidermis.

During respiration, food energy is released as ATP and heat. During cellular respiration, glucose and oxygen are converted into carbon dioxide and water, and energy is transferred to ATP. Respiration should not be confused with breathing, which is a type of ventilation. Respiration is a process that takes place within cells.

Anaerobic respiration often yields less energy than aerobic respiration because the electron transport chain involved is less efficient. Anaerobic respiration - The Food can also be broken down without using oxygen.

Cellular respiration: Cells in our bodies use oxygen for respiration, generating energy and carbon dioxide as a waste product. Gas exchange in lungs: The alveoli in lungs are filled with air rich in oxygen and low in carbon dioxide. Blood flowing through capillaries surrounding the alveoli has lower oxygen and higher carbon dioxide concentrations.

The respiratory system is made up of the organs included in the exchange of oxygen and carbon dioxide. Upper respiratory parts: Nose, Nasal cavity, Mouth, Sinuses, Throat (pharynx). lower respiratory parts : Lungs, Large airways (bronchi), Small airways (bronchioles), Air sacs (alveoli).

Anaerobic respiration consists of two steps - glycolysis and incomplete breakdown of pyruvic acid. Anaerobic respiration cannot continue indefinitely because of the accumulation of poisonous compounds and less availability of energy per gram mole of food broken.