Chapter 15

Question 1

What do extra cellular messenger molecules do?

Answer 1

Transmit messages between cells

Question 2

Autocrine cell signaling:

Answer 2

Cell has receptors on surface that respond to the messenger

Question 3

Paracrine cell signaling:

Answer 3

Messenger molecules travel short distances through extracellular space

Question 4

Endocrine cell signaling:

Answer 4

Messenger molecules reach their target cells through bloodstream

Question 5

Receptor cell signaling:

Answer 5

On or in target sells receive an extra cellular message

Question 6

Ligand cell signalling element:

Answer 6

Molecule that binds to receptors

Question 7

What are signalling pathways?

Answer 7

Consist of a series of protein recruitments, each protein in a pathway alters confirmation of next protein normally by phosphorylation

Question 8

What is the second messenger system?

Answer 8

Responses of a cell signal is sent through this

Question 9

What do kinases add?

Answer 9

Phosphate groups

Question 10

What do phosphatases do?

Answer 10

Remove phosphate groups

Question 11

What is the purpose of target proteins?

Answer 11

Receive a message to alter cell activity

Question 12

What is signal transduction?

Answer 12

The overall process of cell signalling

Question 13

What does protein phosphorylation do?

Answer 13

Change the behaviour of a protein, using different methods

Question 14

What are some extra cellular messengers?

Answer 14

Amino acids, gases, steroids, eicosanoids, peptides and proteins

Question 15

What are some receptor types?

Answer 15

G protein coupled receptors, receptor protein tyrosine kinases, ligand gated channels, steroid hormone receptors

Question 16

What is the largest super family of proteins encoded by animal genomes?

Answer 16

G protein coupled receptors

Question 17

What do phospholipase do?

Answer 17

Split lipids

Question 18

What do phospholipid kinases do?

Answer 18

Phosphorylate lipids

Question 19

What do you phospholipid phosphatases do?

Answer 19

Dephosphorylate lipids

Question 20

What do protein tyrosine kinases do?

Answer 20

Phosphorylate tyrosine residues on target proteins

Question 21

What are the two groups of protein tyrosine kinases?

Answer 21

Receptor protein tyrosine kinases and non-receptor protein tyrosine kinases

Question 22

How are RTK’s activated?

Answer 22

Directly by extra cellular growth and differentiation factors

Question 23

How are non-receptor protein tyrosine kinases regulated?

Answer 23

Indirectly buy extra cellular signals

Question 24

What are the two mechanisms for receptor dimerization?

Answer 24

Ligand mediated dimerization and receptor mediated dimerization

Question 25

What is dimerization?

Answer 25

Brings to kinase domains in close contact for trans auto phosphorylation

Question 26

What is the purpose of autophosphorylation?

Answer 26

Can regulate the receptors kinase activity or serve as binding sites for cytoplasmic signalling molecules

Question 27

How is signal transduction by RTK is usually terminated?

Answer 27

By internalization of the receptor, primarily through clathrin mediated endocytosis

Question 28

What are three alternate fates of RTK‘s?

Answer 28

1. Degraded in lysosomes 2. Return to plasma membrane 3. Become part of endosomal signal in complexes and engage and continued intercellular signalling