Cellular Signals

Question 1

The stimulus response model

Answer 1

• stimulus(change in environment)
• receptor (specialised cell detects change)
• coordination centre (brain spinal cord)
• effector(specialised cell organ response to message)
• response (opposite effect of the stimulus)

Question 2

What do hormones do

Answer 2

Endocrine cells produce hormones which are Carried in the blood stream to exert a specific metabolic effect on a target cell.

Question 3

Differences of hormones

Answer 3

Protien based- eg human growth protien

Lipid based hormone- pass through membrane easily eg steroids

Question 4

What are types of chemical signals

Answer 4

Hormones
Neurotransmitters
Plant regulators
Pheromones

Question 5

What is signal transduction in hydrophilic, protein based hormones

Answer 5

Process where a cell converts one kind of signal or stimulus to another. The chemical events are carried out by the presence of secondary messengers that will bind with specific cellular components that produce a specific response.

Question 6

Signal reception

Answer 6

The first step of cellular communication where protein receptors bind to one signalling molecule with a specific shape

Question 7

Cellular response

Answer 7

Effector proteins are produced be gene regulation stimulated directly by hormone or indirectly by protein hormone. The effector proteins produce cellular responses to the original external signal molecule

Question 8

Transduction pathway diagram

Answer 8

Photos

Question 9

Lipid soluble, hydrophobic, steroid, cell signalling process

Answer 9

Are able to pass through cell membrane. Will interact with protein receptor molecule found in cell cytoplasm. Moves from cytoplasm to nucleus where joins with DNA and gene activation process will begin protein synthesis

Question 10

Lipid signaling process

Answer 10

Photos

Question 11

What does amplification mean

Answer 11

1 signal molecule to produce lots of molecules

Question 12

Step 1 of chemical signal

Answer 12

Arrival of action potential at pre synaptic neurone and causes an influx of calcium ions (facilitated diffusion) and induces vesicles to release their neurotransmitters into synapse (exocytosis)

Question 13

Step 2 chemical signals

Answer 13

The neurotransmitters diffuse across the synapse to receptors on post synaptic membrane

Question 14

Step 3 chemical signal

Answer 14

Neurotransmitters binds to receptors on post synaptic membrane

Question 15

Step 4 chemical signal

Answer 15

Ion channels in the membrane open causing an influx of sodium. May or may not reach threshold to activate neural impulse

Question 16

Step 5 of chemical signal

Answer 16

Neurotransmitters is deactivated by enzyme located on membrane. Components of neurotransmitters are reabsorbed (active transport) back into axon terminal recycled and repacked. Uses mitrocondria

Question 17

How do plant regulators differ from animal hormones

Answer 17

Plant regulators are less specific and can bring about a number of responses based on the environmental conditions.
Whereas hormones can only bring one specific response

Question 18

What are plant chemical messengers called

Answer 18

Plant regulators

Question 19

What is a pheromone

Answer 19

A chemical messenger that are produced within an organism and released to the environment. These signals are received by another organism using specific receptor cites

Question 20

What’s some types of pheromones

Answer 20

Trail phermones
Alarm pheromones
Territorial pheromones
Sex pheromones

Question 21

What is apoptosis

Answer 21

The process of programmed cell death that involved a series of biochemical events and is an example of a transduction bathway

Question 22

What is intrinsic apoptosis

Answer 22

Programmed cell death that begins within the cell.

Question 23

How does intrinsic apoptosis occur

Answer 23

Driven by the mitrochondria and involved enzymes called (capase) that destroys internal organelles and produces chemicals that attract phagocytic cells to engulf cellular parts

Question 24

What is extrinsic apoptosis

Answer 24

When an individual cell is instructed to destroy itself from an external messenger.

Question 25

When does extrinsic aptopis occur

Answer 25

If a cell does not develop correctly (cancer cells) or if there are too many of the type of cell

Question 26

How does extrinsic apoptosis occur

Answer 26

The cell recieves a "death message signal" and the message is recognised by the programmed death cell receptors on the membrane

Question 27

What is the rule for apoptosis

Answer 27

Rate of cell renewal = rate of cell death

Question 28

Cell changes in apoptosis

Answer 28

Cell shrinks Plasma membrane forms bubbles The nucleus and oraganelles condense and fragment The cell breaks up, contents forms parcels Remnants are engulfed by phagocytic cells- this prevents damage to other cells

Question 29

Examples of aptoptis

Answer 29

Dysfunctional, damaged or diseased cells- prevents a virus from replicating or spreading to other cells Embryonic development- final shaping of body parts depends on programmed cell death of excess cells eg skin cells joining toes

Question 30

What are the 5 kinds of plant regulators

Answer 30

``` Auxins Gibberellins Ethylene Cytokinins Absisic acid ```

Question 31

Similarities and differences between animal hormones and plant regulators

Answer 31

Sim- organic and signaling molecules Differences- don't travel in general circulation, are not produced in endocrine glands, are much smaller compared to animal hormones

Question 32

Function of auxin plant hormone

Answer 32

Causes cells to elongate, and more away from the light, this causes ts to grow towards the light

Question 33

Function of gibberellins plant hormones

Answer 33

Cause growth of tissues by causing cells to get longer

Question 34

Function of cytokinins plant regulators

Answer 34

Cause growth by stimulating cells to divide by mitosis

Question 35

Eythylene plant regulators

Answer 35

Helps plants/fruits ripen and mature | Helps flowers open

Question 36

Abscisic acid plant regulators

Answer 36

Brings on dormancy eg autum leaves fall off

Question 37

Malfunction of apoptosis with cancer

Answer 37

Cancer cells can appear from too little apoptosis. Mutations present in cancer cells enable the cells to rapidly grow forming tumours, the cancer cells does not respond to normal apoptosis signal of self destruct

Question 38

Malfunction of apoptosis with Parkinson's and Alzheimer's

Answer 38

Parkinson's disease and alzheimers result form exessive cell death from apoptosis in nerve cells in the brain.