1.1.2 - Cell Membranes (Communication and Cell Signalling) Part 9

Question 1

Define the term ‘cell signalling.’

Answer 1

Cell signalling - When cells communicate to each other via signal molecules.

Question 2

1. What helps cells detect hormones?
2. How are cells able to detect that one hormone is different from another?

Answer 2

1. On the cell surface membrane, there are receptors which detect for any hormones
2. Receptors on the cell have a specific shape. They can only bind on to a specific hormone whose shape is complimentary to their own. The hormones’ specific shape allows the receptors to tell them apart.

Question 3

Describe how signalling molecules, such as a hormone, outside the cell carries out a response in the cell.

Answer 3

• Proteins in the cell membrane act as receptors for these signalling molecules.
• This means they have a specific shape that is complementary to the hormone they can detect and bind on to.
• The signalling molecule binds on to the complementary receptors.
• This triggers a response inside the cell.

Question 4

HIV, which cause AIDs, can inffect humans because it can enter the cells of the immune system. Suggest how HIV can enter these cells.

Answer 4

HIV has a shape that can fit into one of the receptors on the cell surface, allowing it to enter and reproduce inside the cell.