Antibody Structure and Function

The video tutorial explains the structure and function of antibodies, which are proteins that respond to antigens and mediate humoral immunity. Antibodies have a Y-shaped structure composed of two heavy and two light chains, each with variable and constant domains. The video also covers how enzymes like papain and pepsin cleave antibodies into fragments, such as Fab and Fc, which have specific roles in antigen binding and crystallization.

What are antibodies primarily produced in response to?

• Bacteria

• Antigens

• Viruses

• Toxins

Which part of the antibody shows remarkable variability?

• Antigen-binding region

• Fc region

• Hinge region

• Constant region

How many chains make up an antibody molecule?

• Five

• Four

• Three

• Two

What is the shape of an assembled antibody molecule?

• X-shaped

• Y-shaped

• Z-shaped

• L-shaped

What domains do light chains of antibodies consist of?

• One variable and two constant domains

• One variable and one constant domain

• Two variable domains

• Two constant domains

What ensures the links between light and heavy chains in antibodies?

• Van der Waals forces

• Hydrogen bonds

• Ionic bonds

• Disulphide bridges

What happens to an antibody molecule when treated with papain?

• It remains intact

• It splits into two pieces

• It splits into three pieces

• It forms a single fragment

What is the crystallizable fragment of an antibody called?

• Fab

• Fc

• F(ab′)2

• Fv

What fragment is generated when an antibody is treated with pepsin?

• Fab

• Fv

• F(ab′)2

• Fc