Unit 1: Communication within Multicellular Organisms

Question 1

In animals communication is mediated by

Answer 1

nervous transmission and hormonal secretion

Question 2

In a hormonal secretion, what is the nature of the signal?

Answer 2

Extracellular signalling molecules

Question 3

In a nervous transmission, what is the nature of the signal?

Answer 3

Electrical impulses and extracellular signalling

Question 4

In a hormonal secretion, what is the method of transmission of the signal?

Answer 4

Through the bloodstream

Question 5

In a nervous transmission, what is the method of transmission of the signal?

Answer 5

Along the axons of neurons

Question 6

In a hormonal secretion what are the target cells?

Answer 6

Any cells

Question 7

In a nervous transmission, what are the target cells?

Answer 7

Any cells with connections to neutrons (effectors)

Question 8

What is the response time of a hormonal secretion in comparison to a nervous transmission?

Answer 8

Slower

Question 9

What is the response time of a nervous transmission in comparison to a hormonal secretion?

Answer 9

Faster

Question 10

The duration of a hormonal secretion is ______ than a nervous transmission which is transient

Answer 10

longer lasting

Question 11

The extent of response to a hormonal secretion is ?

Answer 11

widespread

Question 12

The extent of a response to a nervous transmission is ?

Answer 12

localised

Question 13

Co-ordination allows what type of response to be made?

Answer 13

integrated homeostatic

Question 14

Extracellular signalling: Stage 1, specific signalling molecules are released as a result of what?

Answer 14

A change in internal state

Question 15

Extracellular signalling: Stage 2, signalling molecules are carried to where?

Answer 15

Target cells

Question 16

Extracellular signalling: Stage 3, signalling molecules arrive at target cells and the cell responds with

Answer 16

a change in the internal state of cells

Question 17

Different cell types produce specific _______ molecules?

Answer 17

signalling

Question 18

How far an effect can a neurotransmitter have (roughly)?

Answer 18

1µm

Question 19

How far an effect can a hormone have (roughly)?

Answer 19

1m

Question 20

How far an effect can animal pheromones have (roughly)?

Answer 20

Up to over 1km

Question 21

How does a target cell ‘know’ that it should respond to a specific signal?

Answer 21

Cells only detect and respond to signals if they possess a specific receptor

Question 22

True or False? Cells can also show a specific tissue response to the same signal

Answer 22

True

Question 23

The ligand adrenaline can bind to a receptor and produce a different response in salivary gland cells and in liver cells. What are the two responses?

Answer 23

In the salivary gland: Amylase release is stimulated

In the liver cells: Glycogen breakdown is stimulated

Question 24

When a hydrophobic signalling molecule binds to a nuclear receptor what is it regulating?

Answer 24

Gene Transcription

Question 25

What type of hormone is a hydrophobic signalling molecule?

Answer 25

Steroid hormones

Question 26

Inactive transcription factor: Stage 1, an inhibitor protein is blocking what binding site on the receptor protein?

Answer 26

DNA binding site

Question 27

Inactive transcription factor: Stage 2, the binding of a steroid hormone to a receptor site cause what to happen?

Answer 27

DNA Binding site becomes exposed as inhibitor protein is removed.

Question 28

Thyroxine is released from where in the body?

Answer 28

The thyroid

Question 29

What is thyroxine?

Answer 29

A hydrophobic hormone that regulates metabolic rate

Question 30

Thyroxine: Stage 1, The transcription of what gene is being inhibited because of the (empty) thyroid receptor bound to DNA?

Answer 30

Na+/K+ATPase gene is inhibited

Question 31

Thyroxine: Stage 2, Thyroxine is released and the receptor protein undergoes what type of change?

Answer 31

A conformational change

Question 32

Thyroxine: Stage 3, Transcription of the Na+/K+ATPase gene takes place now because?

Answer 32

It is no longer being inhibited by the thyroid receptor

Question 33

Thyroxine: Stage 4, This allows more Na+/K+ATPase in the cell membrane, therefore what molecule becomes degraded faster?

Answer 33

ATP

Question 34

Thyroxine: Stage 5, Degrading of ATP increases the _________?

Answer 34

metabolic rate

Question 35

Hydrophillic ligands: What is a hydrophillic ligand?

Answer 35

A molecule that binds to sites on the target proteins (receptors) at the surface of cells to trigger signal transduction.

Question 36

Hydrophillic ligands: Binding of a hydrophillic ligand triggers what?

Answer 36

The receptor protein to undergo a conformational change

Question 37

Peptide hormones are?

Answer 37

Short chains of amino acids

Question 38

Give two examples of relevant peptide hormones?

Answer 38

Anti-diuretic hormone and Insulin

Question 39

What is a neurotransmitter?

Answer 39

Chemical signals that are released from nerve endings that alter the activity of target cells.

Question 40

A good example of hydrophillic signal transduction is the _________ cascade?

Answer 40

Adrenaline (Epinephrine) G-Protein

Question 41

Protein kinase activity: Stage 1, Insulin binds to the ____

Answer 41

receptor

Question 42

Protein Kinase activity: Stage 2, Kinase enzyme ________ itself.

Answer 42

phosphorylates

Question 43

Protein Kinase activity: Stage 3, Receptor phosphorylates insulin receptor substrate called?

Answer 43

IRS-1

Question 44

Protein Kinase activity: Stage 4, Phosphorylated IRS-1 acts on what to trigger cell responses?

Answer 44

effectors

Question 45

Insulin regulates the _____ concentration of the blood

Answer 45

blood glucose

Question 46

Stages of insulin production: Stage 1, Blood glucose concentration rises and a change is detected. This triggers what cells in what organ to produce more insulin?

Answer 46

Beta-cells in the pancreas

Question 47

Stages of insulin production: Stage 2, Insulin is then transported in the blood and what peptide hormone is released and what does it do?

Answer 47

ADH and it acts on adipose, liver and muscle cells

Question 48

Stages of insulin production: Stage 3, More glucose is taken up by cells resulting in?

Answer 48

Blood glucose concentration falls

Question 49

The recruitment of GLUT 4 is induced by?

Answer 49

exercise

Question 50

Diabetes Mellitus: This is a disease caused by what?

Answer 50

Defects in the insulin signalling system

Question 51

What is the cause of type 1 Diabetes Mellitus?

Answer 51

Destruction of beta cells in the pancreas by immune system

Question 52

What is the cause of type 2 Diabetes Mellitus?

Answer 52

Exact cause is unknown, obesity is a risk factor

Question 53

What is the nature of defect in type 1 Diabetes Mellitus?

Answer 53

Pancreas does not produce any insulin

Question 54

What is the nature of defect in type 2 Diabetes Mellitus?

Answer 54

Target cells develop insulin resistance due to loss of receptor function

Question 55

What is the general treatment of type 1 Diabetes Mellitus?

Answer 55

Daily insulin injections and management of diet to control blood glucose concentration

Question 56

What is the general treatment of type 2 Diabetes Mellitus?

Answer 56

Eat less sugar and saturated fat, regular exercise and medication to lower blood glucose concentration

Question 57

ADH regulates what in the body?

Answer 57

The body's water balance

Question 58

ADH regulation: Stage 1, Blood water concentration rises and a change is detected so the body does what?

Answer 58

Release ADH from the pituitary gland

Question 59

ADH regulation: Stage 2, ADH is transported via the blood and ADH acts on what part of the kidney?

Answer 59

The kidney collecting ducts

Question 60

ADH regulation: Stage 3, ADH on the collecting ducts causes more water to reabsorbed into the blood, what effect does this have on urine and blood water concentration?

Answer 60

Less urine is made and blood water concentration falls.

Question 61

Mechanism of action of ADH: ADH binds to ADH receptor causing what to happen?

Answer 61

Activation of protein kinase A

Question 62

Mechanism of action of ADH: Activation of protein kinase A causes what to happen?

Answer 62

Protein phosphorylation

Question 63

Mechanism of action of ADH: Phosphorylation of proteins in the collecting duct of the cell cause what to happen in the lumen

Answer 63

Fusion of vesicles containing AQP 2 water channel proteins

Question 64

Aquaporins are protein channels that allow?

Answer 64

efficient transmembrane movement of water

Question 65

Diabetes insipidus is a disease in which ?

Answer 65

the water concentration mechanism of the kidney fails

Question 66

There are two types of diabetes insipidus which are?

Answer 66

Central diabetes insipidus and nephorgenic diabetes insipidus

Question 67

In central diabetes insipidus, insufficient quantities of what are produced?

Answer 67

ADH

Question 68

In nephrogenic diabetes insipidus, cells in the lining of the collecting duct are?

Answer 68

unable to respond to ADH

Question 69

Symptoms of diabetes insipidus are?

Answer 69

Excessive thirst and large quantities of dilute urine