Cell signaling Flashcards Preview

Biology A-level > Cell signaling > Flashcards

Flashcards in Cell signaling Deck (25)
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1
Q

Importance of cell signalling:

A

All cells and organisms must be able to respond to their changing environment.

2
Q

Signal pathway:

A
  1. stimulus
  2. receptor
  3. transmission of signal
  4. effector
  5. response
3
Q

Transduction is…

A

conversion of the original signal to a message that can be transmitted

4
Q

Transmitting message involves…

A

crossing barriers such as cell surface membranes

5
Q

Signalling molecules are usually very…

A

small for easy transport.

6
Q

Signalling includes both…

A

electrical and chemical events and their interactions with each other.

7
Q

The cell surface membrane is critical…

A

component of most signalling pathways because it is a barrier to the molecules.

8
Q

In typical signalling pathway, molecules…

A

must cross or interact with the cell surface membrane

9
Q

Signalling molecules are very…

A

diverse.

10
Q

If the signalling molecule is hydrophobic such as…

A

steroid hormones it can diffuse directly across the cell surface membrane and bind to receptors.

11
Q

Most of the signalling molecules are…

A

water soluble.

12
Q

(Typical signalling pathway) Starts with signal arriving…

A

at a protein receptor in a cell membrane.

13
Q

(Typical signalling pathway)The receptor has a specific…

A

a shape which recognises the signal. (only cells with this receptor can recognise it)

14
Q

(Typical signalling pathway)The signal brings a change in…

A

the shape of the receptor, this spans the membrane and message is passed to the inside of the cell. (signal transduction)

15
Q

(Typical signalling pathway)The change in shape of the receptor allows…

A

interaction with the next component.

16
Q

(Typical signalling pathway)The next component is often…

A

G-protein, which releases a second messenger. Many of second messengers can be made, in response to one receptor.

17
Q

The second messenger is…

A

a small molecule which diffuses through the cell relaying the message.

18
Q

(Typical signalling pathway)Many produced second messengers represent…

A

amplification of the original signal.

19
Q

(Typical signalling pathway)The second messengers usually activate…

A

enzymes, increasing the amplification at each sage.

20
Q

(Typical signalling pathway)Finally, a required enzyme is…

A

produced which brings the required change in cell metabolism.

21
Q

Signalling cascade is…

A

a sequence of events triggered by the G-protein.

22
Q

(Other ways of alerting the activity of a cell by receptor)Opening an ion channel, resulting…

A

in a change of membrane potential

23
Q

(Other ways of alerting the activity of a cell by receptor)Acting directly as…

A

a membrane-bound enzyme(e.g. insulin receptor)

24
Q

(Other ways of alerting the activity of a cell by receptor)Acting as an intracellular receptor when…

A

the initial signal passes straight through the cell surface membrane.

25
Q

Direct cell contact is…

A

another mechanism of signalling.