Cell signalling 5.1.3

Question 1

What is cell signalling?

Answer 1

The process by which cells communicate with each other

Question 2

Why is cell signalling important?

Answer 2

It allows multicellular organisms to control and coordinate their bodies and to respond to their environments.

Question 3

Describe the basic stages of cell signalling

Answer 3

• A stimulus is received by a receptor cell
• The stimulus is converted to a signal (nearly always a chemical) that can be passed on - this process is known as transduction
• The signal is transmitted to a target cell (effector) that can detect it (via receptors in the cell membrane)
• An appropriate response is made

Question 4

What are the two types of cell signalling in animals?

Answer 4

• Paracrine signalling -> between cells that are close together
• Endocrine signalling -> between cells that are far apart, through the use of hormones

Question 5

How does the transmission of messages in cell signalling pathways occur?

Answer 5

It requires crossing barriers such as cell surface membranes - this is achievable as cell signalling molecules are usually very small

Question 6

Give some examples of cell receptors

Answer 6

• Proteins
• Glycoproteins
• Cytoplasm -> because steroid hormones can diffuse through the cell membrane)