16.1

Question 1

Cells sensing and responding to their environment can result in changes to their…

Answer 1

movement, shape, metabolism, gene expression

Question 2

cells can act as both _______ and _______ cells

Answer 2

signalling ; targetting

Question 3

in multicellular organisms, cell communication is vital for the coordination of..

Answer 3

reflexes, behaviours, development, and survival

Question 4

What is the basic process of Cell Signalling?

Answer 4

Reception - Transduction - Response

Question 5

What happens during Reception?

Answer 5

• target cell detects a signal (ligand) from the environment
• signal binds to a receptor protein on the cell surface, or within the cell

Question 6

What happens during Transduction?

Answer 6

• receptor protein undergoes a change upon binding
• this change initiates transduction, converting the signal into a form that induces a cellular response

(Transduction can occur in a single step or through a signal transduction pathway involving relay molecules)

Question 7

What happens during Response?

Answer 7

• cell’s response varies from enzyme catalysis to cytoskeleton rearrangement or activation of specific genes
  (Ensure correct processes occur in the right cells at the right time)

Question 8

What are the 2 signal types?

Answer 8

Long range & Short range

Question 9

What is Long-Range Signalling?

Answer 9

Hormones travelling through the bloodstream

Question 10

What is Short-Range Signalling?

Answer 10

Local mediators and direct contact

Question 11

Describe the specificity of Cell Repsonses

Answer 11

Cells are exposed to numerous signals but only respond to specific ones based on the receptors they express

Question 12

Receptor protein expression is dynamic. They can be _______ , _______ , or _________

Answer 12

Inactivated ; Internalized ; Degraded

Question 13

True or False: The same signal only induces one sort of response, in different cells.

Answer 13

False: The same signal can induce different responses in different cells

Question 14

Signal response speed depends on what?

Answer 14

on whether it requires changes in gene transcription/translation (slow responses) or existing protein modifications (fast responses)

Question 15

What are the 2 kinds of receptors?

Answer 15

1. Intracellular Receptors
2. Plasma Membrane (cell surface)

Question 16

Plasma membrane/cell surface receptors are for…

Answer 16

large, hydrophilic molecules that cannot pass through the membrane

Question 17

Intracellular Receptors are for…

Answer 17

small, hydrophobic molecules, that can diffuse across the membrane

Question 18

Steroid hormones are an example of what kind of receptor?

Answer 18

Intracellular Receptor

Question 19

Describe the action of the Steroid Hormone.

Answer 19

Hormones like cortisol bine to intracellular receptors that act as transcription regulators, altering gene expression