M25. Cell communication Flashcards Preview

Module 2 - biology > M25. Cell communication > Flashcards

Flashcards in M25. Cell communication Deck (13)
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1

What is cell signalling?

the communication between cells that allows effective coordination of a response.

2

How is cell signalling achieved?

through cell surface molecules and the release of hormone like chemicals called cytokines

3

What do B lymphocytes and T lymphocytes have that allow them to detect foreign invaders?

receptor sites that are complementary to the foreign antigens (whether that is an isolated protein, attached to a pathogen, or on the surface of a host cell.)

4

What sort of information is communicated?

identification
distress signals
antigen presentation
instructions

5

How are cells identified?

As pathogens carries antigens that act as markers

6

How do cells send distress signals?

If part of a pathogen ends up attached ti the hosts plasma membrane, then they either:
1. act as distress signals and can be detected by cells from the immune systems
2. act as markers to indicate that the cell has been infected, which t killer cells can recognise.

7

How is antigen presentation communicated?

As macrophages act like phagocytes and engulf and digest the pathogen, but they dont fully digest it, instead they separate out the antigens and incorporate them into a cell surface molecule which is then exposed on the surface of the macrophage which becomes known as the antigen-presenting cell.

8

What is the role of an antigen-presenting cell?

to find the lymphocytes that can neutralise that particular antigen.

9

How is information communicated between cells?

As there are a range of cytokines released by cells that act as instructions to their target cells by binding to specific membrane-bound receptors on the target cell which causes a second set of messengers to be released inside the cell which then takes an effect on the cell.

10

Give 4 examples of communication using cytokines

-macrophages release monokines that attract neutrophils (by chemotaxis, the movement of cells towards a particular chemical)
-macrophages released monokines that can stimulate B cells to differentiate and release antibodies.
- T cells, B cells and macrophages release interleukins, which can stimulate proliferation and differentiation of B and T cells.
- Many cells can release interferon, which can inhibit virus replication and stimulate the activity of T killer cells.

11

What is chemotaxis?

that attract neutrophils (by chemotaxis, the movement of cells towards a particular chemical

12

Describe the communication between cells in the specific immune response.

-Pathogen is engulfed by cells from the immune system
- Removal of antigens from pathogen
- Antigen presentation
-Reproduction of T killer and helper cells
T KILLER:
-t killer cells search for infected cells.
-T killer cells attach to infected cells
- T killer cells secrete toxic substances into infected cells to kill the cell and the pathogens it contains
T HELPER:
-release of interleukins
-activation of B cells
- Reproduction of B cells
- Some B cell clones differentiate to make plasma cells, which manufacture antibodies
- Some B cell clones differentiate to make B memory cells which circulate in the body to provide immunilogical memory.

13

Describe how T killer cells destroy pathogens

-Pathogen is engulfed by cells from the immune system
- Removal of antigens from pathogen
- Antigen presentation
-t killer cells search for infected cells.
-T killer cells attach to infected cells
- T killer cells secrete toxic substances into infected cells to kill the cell and the pathogens it contains