Question

What is the main respiratory substrate?

Answer 1

Respiration is defined as the movement of oxygen from the outside environment to cells within tissues, as well as the removal of carbon dioxide in the opposite direction, according to physiology. The physiological definition of respiration is distinct from the biochemical definition, which describes a metabolic process in which an organism obtains energy (in the form of ATP and NADPH) by oxidizing nutrients and releasing carbon dioxide.

Complete answer:
Although cellular respiration and thus life in animals are dependent on physiologic respiration, the two processes are distinct: cellular respiration occurs in individual cells of the organism, whereas physiologic respiration involves the diffusion and transport of metabolites between the organism and the external environment.
Cellular respiration is a set of metabolic reactions and processes that occur within organisms' cells to convert chemical energy from oxygen molecules or nutrients into adenosine triphosphate (ATP) and then release waste products. Respiration involves catabolic reactions, which break large molecules down into smaller ones, releasing energy due to weak high-energy bonds.
One of the most important ways a cell releases chemical energy to fuel cellular activity is through respiration. A series of biochemical steps, some of which are redox reactions, make up the overall reaction. Even though cellular respiration is technically a combustion reaction, it does not resemble one when it occurs in a living cell due to the slow, controlled release of energy from a series of reactions.
Sugar, amino acids, and fatty acids are common nutrients used by animal and plant cells in respiration, and molecular oxygen is the most common oxidizing agent that provides the majority of the chemical energy.
Respiratory substrates are compounds that are oxidized during the process of respiration. Carbohydrates, particularly glucose, serve as a source of respiratory energy. Depending on the physiological canditech of an organism's body, fats, proteins, and organic acids can also act as respiratory substrates. The main respiratory substrate is glucose.
Since different energy pathways are used for fats, carbohydrates, and proteins, the respiratory quotient value indicates which macronutrients are being metabolized. The respiratory quotient for lipid metabolism is approximately 0.7, for proteins, it is approximately 0.8, and for carbohydrates, it is approximately 1.0.

Therefore, Glucose is the main respiratory substrate.

Note:
Adults breathe between 12 and 15 times per minute, while newborns breathe between 30 and 60 times per minute. The network of organs and tissues that help you breathe is known as your respiratory system. This system assists your body in absorbing oxygen from the air so that your organs can function properly. It also removes waste gases from your blood, such as carbon dioxide.