2.5 Cell Signalling Flashcards Preview

A Level Biology > 2.5 Cell Signalling > Flashcards

Flashcards in 2.5 Cell Signalling Deck (25):
1

Why do cells need to communicate with each other?

To control processes within the body and respond to changes in environment

2

What do cells communicate using?

Messenger molecules (e.g. Hormones, neurotransmitters)

3

What are the steps involved in cell signalling?

- 1 cell releases messenger molecule
- molecule travels to another cell (e.g in the blood)
- messenger molecule is detected by the cell as it binds to a receptor on its membrane

4

What messengers are able to pass straight through the membrane? Why?

Steroid hormones such as testosterone
Because they are small and non polar enough

5

Because most messengers are unable to pass through the membrane what must they bind to?

Membrane bound receptors

6

In order for cells to survive what must cells do?

Communicate with each other

7

What do proteins in the cell membrane act as?

Receptors for Messenger molecules

8

When do receptor proteins have and what does this mean for the messenger molecules?

They have a specific shape
Only messenger molecules with a complimentary shape can bind

9

What do different cells have?

Different types of receptors that respond to different messenger molecules

10

What is a cell called that responds to a particular messenger molecule?

A target cell

11

Give an example of a messenger molecule that binds to a target cell:

Glucagon- a hormone released when there isn't enough glucose in the blood. It binds to receptors on liver cells causing the cell to break down stores of glycogen to glucose

12

What are many membrane bound receptors and what are they often called?

Integral proteins often called transmembrane receptors

13

Name the three parts/domains of transmembrane receptors:

• extra cellular domain
• transmembrane domain
• intercellular domain

14

What is the extra cellular domain?

The part that sticks out of the cell to which a messenger binds

15

What is the transmembrane domain?

The part buried within the membrane

16

What is the intercellular domain?

The part that sticks into the cell and relays the signal to the cell

17

How do many drugs work?

By binding to receptors in cell membranes

18

What do drugs that bind to receptors do?

• trigger a response
• or block the receptor preventing it from working

19

What are agonists?

Drugs that bind to receptors and mimic the bodies normal messengers

20

Give an example of an agonistic drug:

Ritalin which is used to treat ADHD by increasing dopamine levels in the body

21

What are antagonists?

Drugs that bind to receptors and block the bodies normal messengers

22

Give an example of an antagonist drug:

Haloperidol used to treat schizophrenia by suppressing dopamine receptors

23

Are antihistamines agonists or antagonists?

Antagonists

24

What do antihistamines do?

Block histamine receptors in cell surfaces, preventing histamine binding to the cell causing inflammation

25

How is histamine released and what does it do?

- release is caused by cell damage
- histamine binds to receptors in the surface of other cells causing inflammation

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