Punjab board chemistry notes class 10 notes chapter 13 biochemistry short long questions, MCQs, and multiple-choice questions pdf Download.
Biochemistry Punjab Board Chapter 13
Where are the proteins found?
Proteins are present in all living organisms throughout their bodies. They are major components of all cells and tissues of animals. Over 10,000 different proteins are found and needed in the body for maintaining life. They are found in muscles, bones, skin, hair, and virtually every other body part.
Describe the uses of carbohydrates.
Uses of carbohydrates
(i) Carbohydrates provide energy for working muscles.
(ii) They regulate the amount of sugar level in our body.
(iii) They provide fuel for the central nervous system.
(iv) They help muscles of the intestines to move food efficiently through the digestive tract.
(v) They help in lowering cholesterol and regulating blood pressure.
How do plants synthesize carbohydrates?
Plants synthesize carbohydrates from carbon dioxide and water by photosynthesis in the presence of sunlight and green pigment chlorophyll.
Give the characteristics of monosaccharides
Characteristics of monosaccharides
(i) They are the simplest form of sugar.
(ii) They are usually white crystalline solids.
(iii) They are sweet in taste.
(iv) They are soluble in water.
(v) They are reducing in nature.
Give an example of a disaccharide. How it is hydrolyzed or monosaccharides.
Carbohydrates which on hydrolysis produce two monosaccharides are called disaccharides. Lactose is a disaccharide of glucose and galactose i.e. it produces two monosaccharides on hydrolysis as shown below:
C12H22O12 + H2O → C6H12O6 + C6H12O6
Lactose Glucose Galactose
Why the ten amino acids are essential for us?
The ten amino acids are essential for us because, unlike non-essential amino acids, they cannot be synthesized by our body. As a result, they must come from food.
How are proteins formed?
A protein molecule is made from a long chain of amino acids, each linked to its neighbour through a covalent peptide bond with a loss of water molecule. The carbon atom from the carboxyl group of one amino acid shares electrons with the nitrogen atom from the amino group of the second amino acid.
How is gelatin obtained?
Gelatin is a protein obtained by heating bones and tendons in water.
Give the general formula of the lipids.
The general formula of lipids is:
Name two fatty acids with their formulae
Butyric acid: C3H7COOH
Palmitic acid: C15H31COOH
Give the types of vitamins.
Types of vitamins
There are two types of vitamins.
(i) Water-soluble vitamins
Water-soluble vitamins dissolve in water. These vitamins are carried to the body’s tissues but are not stored in the body. If taken in excess, they are readily excreted from the body. Hence, they are not toxic even if taken in excess.
Examples: Vitamin B complex and Vitamin C
(ii) Fat-soluble vitamins
Fat-soluble vitamins dissolve in fat. Taking a large quantity of these vitamins can cause diseases. However, their deficiency can also be harmful.
Examples: Vitamin A, D, E and K.
What is the significance of vitamins?
Significance of vitamins
Vitamins are used in many different ways inside our bodies. They boost the immune system, support normal growth and development and help cells and organs do their jobs. Overall, vitamins make bodies work properly. While vitamins do not directly serve as a source of energy, they do help the enzymes that generate energy from nutrients such as carbohydrates and fats.
Describe the sources and uses of vitamin A.
Sources of vitamin A
High vitamin A foods include milk, butter, eggs, oils and fats, fish. It is also found in fresh green vegetables, carrots and liver.
Uses of vitamin A
Vitamin A supports healthy eyesight, immune function, skin, bones and teeth.
What do you mean by the genetic code of life?
The genetic code is the set of rules by which information stored in DNA is passed as instructions from generation to generation on how to synthesize particular proteins from amino acids. This information determines whether an organism is a man, donkey or a tree. It also determines the type of cell.
What is the function of DNA?
Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the development and function of living things. It contains all the information for making a complete individual. All known cellular life and some viruses contain DNA. The main role of DNA is the storage of information and its transmission to next generations.