What are Vitamins?

Questions and Answers

To serve as coenzymes for enzymatic reactions

Based on their solubility in water or fat

Bioavailability

Precursors Signup and view all the answers

Because they are required for multiple biochemical reactions Signup and view all the answers

In their structure and function Signup and view all the answers

Micrograms Signup and view all the answers

They are converted to active forms of the vitamin Signup and view all the answers

Because they are organic and can be destroyed Signup and view all the answers

Because of the ultraviolet rays of the sun or fluorescent light Signup and view all the answers

Water-soluble vitamins are absorbed directly into the blood, while fat-soluble vitamins enter the lymph first Signup and view all the answers

Vitamin C Signup and view all the answers

Reduced action of the vitamin in the body Signup and view all the answers

Their solubility in water or fat Signup and view all the answers

Attached to protein carriers Signup and view all the answers

In the fatty tissues and liver Signup and view all the answers

Study Notes

Vitamins are nutrients required for maintaining body functions such as immunity and metabolism.
They are essential for various biochemical reactions, growth, survival, and reproduction of an organism.

Vitamins are classified as either fat-soluble (lipid soluble) or water-soluble based on solubility.
Fat-soluble vitamins include A, D, E, and K.
Water-soluble vitamins include C and B.

Vitamins are individual units, not linked together like carbohydrates, fats, and proteins.
They do not yield usable energy when broken down, but assist enzymes in releasing energy from other nutrients.
Vitamin content in food is measured in micrograms (µg) or milligrams (mg).

Bioavailability refers to the amount of vitamins available from foods and absorbed by the body.
Some vitamins are available in inactive forms called precursors or provitamins, which are converted to active forms within the body.

Vitamins are organic and can be destroyed, losing their functionality.
They must be handled with care during storage and cooking to prevent destruction.
Prolonged heating can destroy thiamin, while ultraviolet rays or fluorescent light can destroy riboflavin.
Oxygen can destroy vitamin C, leading to losses during food processing and storage.

Vitamins are either hydrophilic (water-soluble) or hydrophobic (fat-soluble), like carbohydrates and proteins.
Solubility affects absorption, transport, storage, and excretion of vitamins by the body.
Water-soluble vitamins are found in watery food compartments, while fat-soluble vitamins occur in fats and oils.
Water-soluble vitamins move directly into the blood, while fat-soluble vitamins enter the lymph before the blood.
In the blood, water-soluble vitamins travel freely, while fat-soluble vitamins require protein carriers for transport.