This document discusses the role and function of proteins as well as their biological value. It outlines that proteins are primarily used in the body to build, maintain and repair tissues. They also produce enzymes, provide structure, act as hormones, store substances, and help with muscle contraction and blood coagulation. The biological value of a protein refers to the percentage of absorbed nitrogen that is retained in the body, and is a measure of protein quality. High biological value proteins include meat, eggs, milk, fish and cheese, while low biological value proteins include cereals, nuts, pulses and bread.

1. BIOCHEMISTRY AND CLINICAL
PATHOLOGY
D.Pharm 1st year
TOPIC- PROTEINS
Part-2
Presented by-
SHWETA MISHRA
HYGIA GROUP OF INSTITUTION

2. CONTENTS
❏ Role or function of Proteins
❏ Biological value of Proteins

3. ROLE OR FUNCTION OF PROTEINS
❏ Protein is primarily used in the body to build, maintain and repair
body tissues.
❏ Protein is the major source of energy.
❏ Protein produces enzymes that increases the rate of chemical
reactions reactions in the body.
❏ Protein helps to store other substance in the organism. Eg. Iron
is stored in the liver in a complex with the protein Ferritin.
❏ They provide structural frame-work for cells and tissues.
❏ They act as enzymes and hormones.

4. ❏ Protein exert osmotic pressure which helps in maintaining
electrolyte and water balance.
❏ Proteins can be catabolised to release energy.
❏ Receptor proteins binds with specific substances like vitamins and
minerals and mediate their cellular action.
❏ They help in muscle contraction(myosin, actin).
❏ They help in maintaining osmotic pressure.
❏ They help in the process of coagulation(Thrombin, Fibrinogen).
❏ They help in acid-base balance of the body.
❏ During starvation proteins(amino acids) serve as the major
suppliers of energy.

5. ❏ Cell secretion such as mucus(glycoproteins) help in protection
and provide a slippery texture.
❏ G-protein is one of the regulatory proteins by which the
hormonal signals are transmitted to the nucleus in the cell.
❏ Proteins also control DNA replication, protein synthesis, chain
initiation, chain termination etc.

6. BIOLOGICAL VALUE OF PROTEINS
❏ Karl Thomas has first used the term biological value.
❏ Biological value of protein is used as a measure of protein
quality.
❏ Biological value is defined as the “percentage of absorbed
nitrogen which is retained retained in the body”.
BV= N2 retained
N2 absorbed 100

7. Eg. Bread Eg. Meat
Cereals Fish
Nuts Eggs
Pulses Milk
Cheese
Low
biological
value
foods
High
biological
value
foods

8. THANK YOU