Unit 1: Cells and Proteins 2

Question 1

Signal Transduction occurs when extracellular messages are

Answer 1

hydrophillic

Question 2

Signal Transduction transduces messages of

Answer 2

hydrophillic molecules

Question 3

There are three systems of signal transduction:

Answer 3

• Ion channel coupled receptors
• G-protein coupled receptros
• Enzymes coupled receptors

Question 4

Ligand Gated ion channels: Vesicles contaning neurotransmitter do what?

Answer 4

Fuse with membrane

Question 5

Ligand Gated Ion channels: Neurotransmitter cross synapse and binds to

Answer 5

receptor channel protein causing it to open

Question 6

Ligand Gated Ion channels: Now the channels are open what molecules flows in and depolarises the membrane?

Answer 6

Na+

Question 7

Ligand Gated Ion channels: Depolarisation of the membrane triggers what to open?

Answer 7

more local voltage gated channels to open, allowing in even more Na+

Question 8

Ligand Gated Ion channels: Allowing in lots of Na+ creates a what?

Answer 8

Action potential across the plasma membrane

Question 9

G-Protein coupled signalling regulated ion channels: Receptor becomes active due to binding and activates what?

Answer 9

G-protein molecule

Question 10

G-Protein coupled signalling regulated ion channels: Activated G-protein moves to activate

Answer 10

the potassium ion channel

Question 11

G-Protein coupled signalling regulated ion channels: Now the channel is open, potassium flows

Answer 11

out down its electrochemical gradient

Question 12

G-Protein coupled signalling regulated ion channels: Acetylcholine can reduce ______ activity

Answer 12

muscle

Question 13

G-Protein coupled signalling regulated ion channels: Releasing potassium balances out ____ being released into the cytoplasm.

Answer 13

Na+

Question 14

G-Protein coupled signalling regulated ion channels: The release of the K+ balancing out Na+ makes it difficult for the membrane to

Answer 14

depolarise triggering cell contraction.

Question 15

G-Protein coupled signalling regulated ion channels: Acetylcholine binds to

Answer 15

inactive receptor

Question 16

G-Protein coupled signal Transduction: Ligand such as adrenaline binds to

Answer 16

g-protein

Question 17

G-Protein coupled signal Transduction: After binding of ligand, what is released by the g-protein?

Answer 17

An alpha subunit

Question 18

G-Protein coupled signal Transduction: The alpha subunit binds to

Answer 18

Adenylyl Cyclase

Question 19

G-Protein coupled signal Transduction: Binding of the alpha subunit to adenlyl cyclase causes

Answer 19

adenlyl cylcase to change from inactive to active

Question 20

G-Protein coupled signal Transduction: Active Adenlyl cylcase now converts ATP to

Answer 20

cAMP

Question 21

G-Protein coupled signal Transduction: cAMP attaches to what?

Answer 21

The regulatory section of the protein kinase

Question 22

G-Protein coupled signal Transduction: cAMP binding to the regulatory portion of protein kinase causes the kinase to

Answer 22

split, and ATP bind to the catalytic sections

Question 23

G-Protein coupled signal Transduction: The ATP/kinase molecules now bind to

Answer 23

phosphorylase which uses up the ATP to break up glucose chains

Question 24

G-Protein coupled signal Transduction: cAMP is destroyed by

Answer 24

cAMP phosphodiesterase

Question 25

G-proteins G12 & G13 promote

Answer 25

actin-myosin contraction resulting in cytoskeletal remodelling.

Question 26

G-protein G1 is involved with

Answer 26

actin fibre polymerisation and membrane protrusion

Question 27

G1 protein pathway: Step 1 - G1 receptor stimulated. Then the _____ pathway is stimulated

Answer 27

RAC

Question 28

G1 protein pathway: Once RAC pathway is stimulated, what molecule is produced?

Answer 28

Phosphatidyl inositol triphosphate (PIP3) produced.

Question 29

G1 protein pathway: Production of PIP3 results in

Answer 29

induced polymerisation of actin filaments and extrusion of the cell towards the stimulus

Question 30

G12 and G13 protein pathway: G12 & G13 protein receptor is stimulated which causes the stimulation of what pathway ?

Answer 30

RHO pathway.

Question 31

RHO and RAC pathways are

Answer 31

antagonistic

Question 32

Olfactory Sensitivity: G-protein coupled receptors are sensitive to

Answer 32

odours

Question 33

Enzyme-coupled signalling: Binding of a ligand stimulates a

Answer 33

transmembrane enzyme directly

Question 34

The transmembrane receptor binds to the ligand undergoing a conformation change thus

Answer 34

activating the inactive enzyme

Question 35

Enzyme-coupled Signalling Case Study: Receptor Tyrosine Kinases, ligand stimulates ___________ of tyrosine amino acids

Answer 35

auto-phosphorylation

Question 36

Enzyme-coupled Signalling Case Study: Ligands stimulate autophophorylation of tyrosine amino acids by activation of their

Answer 36

catalytic site

Question 37

Enzyme-coupled Signalling Case Study: Insulin, binds to the receptor activating tyrosine kinase begining a cascade of four intracellular messages:

Answer 37

* Glut-4 transporter to plasma membrane and influx of glucose * glycogen synthesis * Glycolysis * Fatty acid synthesis

Question 38

Enzyme-coupled Signalling Case Study: Cell Growth Factors stimulate cell

Answer 38

proliferation and growth

Question 39

Genes that encode cell growth factor and their receptors are mainly what type of cell?

Answer 39

Proto-oncogenes

Question 40

Oncogenes promote

Answer 40

uncontrolled cell division

Question 41

Proto-oncogenes promote

Answer 41

cell proliferation and growth

Question 42

Epidermal growth factor (EGFR) is coded for by

Answer 42

proto-oncogene

Question 43

The receptor of epidermal growth factor is an

Answer 43

receptor tyrosine kinase

Question 44

One effect of epidermal growth factor is stimulation of

Answer 44

the transcription and expression of epidermal growth factor

Question 45

Over expression of epidermal growth factor is linked to

Answer 45

cancer

Question 46

Some drugs and monoclonal antibodies try to block what receptors?

Answer 46

Receptor Tyrosine Kinases

Question 47

Herceptin and Erbitux are ?

Answer 47

Monoclonal antibodies

Question 48

Herceptin and Erbitux block two types of ____ receptor (Her 1 & Her 2) that are over expressed in breast cancer.

Answer 48

Epidermal growth factor

Question 49

Iressa is a __________ that blocks over expressed EGF receptors in some lung cancer cells

Answer 49

tyrosine kinase inhibitor

Question 50

Fibroblast Growth Factors are a branch of ligands involved in the control of

Answer 50

cell growth, cell differentiation, vascularisation, wound healing and embryo growth.

Question 51

Receptor FGFR3 has been associated with bone growth as FGFR3 stimulation ...

Answer 51

inhibits the formation of bone from cartilage.

Question 52

Mutations in FGFR3 have been associated with

Answer 52

achondroplasia the most common form of dwarfism.

Question 53

Achondroplasia is a condition in which sufferers inherit an allele for

Answer 53

mutated FGFR3 that is overly active