Hormones and Cell Signalling

Question 1

What is cell signalling?

Answer 1

cells communicate with each other using signals, many mols act as signals - some signal during processes taking place inside cells, other signal from cell to another. Example: cytokines

Question 2

What are cell surface membrane proteins usually made of?

Answer 2

Protein mols or modified protein mols

Question 3

What is a target cell?

Answer 3

Any cell with a receptor for a hormone mol

Question 4

What is one example of a hormone receptor?

Answer 4

insulin receptor, insulin made from beta cells in islets of Langerhans in pancreas in response to increased blood sugar, receptors on muscle and liver cells, when attached initiates a internal response in cell = more glucose channels in plasma membrane = more glucose taken up

Question 5

What do medicinal drugs do to receptors? What are 2 examples?

Answer 5

block receptors (complementary shape), beta blockers prevent heart muscle from increasing the heart rate. Some drugs mimic neurotransmitters (for schizophrenia)

Question 6

How do viruses enter cells?

Answer 6

Binding with receptors on cell’s plasma membrane (normally for host’s signalling mols)

Question 7

How can the Human immunodeficiency virus infect humans?

Answer 7

enter cells of the immune system, shape fits into receptors of some immune cells (helper T-lymphocytes) after entering the HIV can reproduce in the cell and eventually destroy it = AIDS

Question 8

What is an example of a poison binding with receptors?

Answer 8

Toxin from bacterium Clostridium botulinum bind with receptors on muscle fibres and prevents them from working = paralysis. Lethal but used in small quantities as BOTOX to reduce wrinkling of skin