Chapter 7: Cell Signaling

Question 1

What do cells use to communicate

Answer 1

Proteins, Ions, small molecules and etc.

Question 2

What are the three main stages of signaling

Answer 2

Reception, Transduction and Response

Question 3

What happens in reception?

Answer 3

A signaling molecule binds to a protein receptor and makes it do things (membrane or in cell)

Question 4

What happens in transduction?

Answer 4

A series of relay molecules carry a signal into a cell and amplifies the signal

Question 5

What happens in response?

Answer 5

The signal causes changes in the cell like gene expression and protein activity

Question 6

What is a ligand

Answer 6

The chemical signal that is received in reception (ions, proteins or small molecules)

Question 7

Receptor

Answer 7

Protein structures that receive ligands, can be integral proteins in plasma membrane or can be in cytoplasm

Question 8

What are the three main classes of protein receptors

Answer 8

G-protein coupled receptors, Receptor tyrosine kinases, Ion channel receptors

Question 9

How do G-Protein coupled receptors work?

Answer 9

A ligand binds to GPCR changing its shape, A GDP leaves the GPCR and a GTP (from cytosol) takes its place activating the G-protein. The GTP binds to an enzyme activating it, the enzyme makes a messenger molecule called cyclic AMP (cAMP) initiating transduction. The GTP is hydrolyzed on its way back returning as GDP to the GPCR

Question 10

Components of G-protein receptors

Answer 10

GPCR (receptor binding site), A membrane anchored G protein (GDP (on) or GTP (off)) and a membrane bound enzyme

Question 11

What is Rhodopsin

Answer 11

A GPCR in rod cells that make up a retina

Question 12

What is a retinal?

Answer 12

A molecule that binds to Rhodopsin

Question 13

What are RTKs?

Answer 13

Receptor tyrosine kinases, monomers that make up GCPR, have binding sites outside the membrane but exist in the membrane, when they receive a signal molecule they bind together and form dimers. They then use 6ATP to become fully activated by attaching 6 phosphate groups to each of their 3 tyrosine ends. Relay proteins bind to them kicking off transduction

Question 14

What is a Kinase

Answer 14

An enzyme that can add a phosphate group onto something

Question 15

What are RTKs used for

Answer 15

Triggering cell division, differentiate cell types and dictate whether or not a cell kills itself

Question 16

What is apoptosis

Answer 16

cell suicide

Question 17

What are ligand gated ion channels

Answer 17

Receptors that control a gate, only open when a ligand is present

Question 18

Transcription factors

Answer 18

proteins that can bind DNA at specific nucleotide sequences and turn on the transcription of specific genes

Question 19

What is phosphorylation cascades?

Answer 19

A way which transduction occurs. Uses A chain of kinases to take phosphate from ATP and then passes it along to a protein activating the protein. When the cause for transduction is removed, all the phosphate groups are removed from every kinase and protein deactivating all of them.

Question 20

What are 3 secondary messengers that also conduct transduction

Answer 20

cAMP(made by adenylyl cyclase), calcium ions let in by ligand gates a fuck ton more we aint gettin into