Chapter 11 Non-Test

Question 1

What determines cell response?

Answer 1

The combined effects of multiple signals.

Question 1

What do cells in a multicellular organism communicate with?

Answer 1

Chemical Messengers via gap junctions or cell-cell recognition

Question 2

What is the difference in Local and Long Distance signaling?

Answer 2

Local signaling is done by cells that are very close to each other. Long distance signaling is done with two cells that are far apart.

Question 3

What is paracrine signaling?

Answer 3

Paracrine signaling is when a cell produces a signal that induces changes in nearby cells.

Question 4

What is Synaptic signalling?

Answer 4

Synaptic Signalling is when a neurotransmitter is sent across a gap between two cells to open gated channels.

Question 5

What two types of ligands are there?

Answer 5

Non-polar and Polar.

Question 6

What is a ligand?

Answer 6

A ligand is a signaller that induces a change in a target cell.

Question 7

What can Nonpolar ligands do that Polar ligands cannot?

Answer 7

Nonpolar ligands can pass through the cell membrane unaided and bind to a cytoplasmic receptor.

Question 8

What do steroids do?

Answer 8

Steroids toggle genes.

Question 9

What do most water-soluble signal molecules do?

Answer 9

Most water soluble molecules bond to specific sites on receptor proteins.

Question 10

What are the three main types of membrane receptors?

Answer 10

1. G Protein-coupled receptors
2. Receptor tyrosine kinases
3. Ion channel receptors

Question 11

What does an Ion channel linked receptor do?

Answer 11

An Ion channel linked receptor is characterized by a very quick opening of a ligand gated ion channel receptor.

Question 12

What does an Ion channel linked receptor allow for the movement of?

Answer 12

Ions.

Question 13

What is a G-protein linked receptor?

Answer 13

A G protein linked receptor is a more general receptor. A G Protein linked receptor functions by giving a GTP energy molecule to a G Protein, which in turn binds to another protein and alters its activity.

Question 14

What is the structure of the G-protein linked receptor?

Answer 14

A G-Protein linked receptor is made up of a single polypeptide chain that goes up and down through the plasma membrane exactly seven times.

Question 15

What is a Cascade?

Answer 15

A cascade is when a G-protein linked receptor activates a protein that activates another protein that activates another protein etc…

Question 16

What is a Kinase?

Answer 16

A Kinase is an enzyme that facilitates the transfer of a phosphate from phosphate donating molecules to proteins in order to activate or deactivate them.

Question 17

What is a Phosphatase?

Answer 17

A Phosphatase splits up a molecule into an alcohol and a phosphate.

Question 18

What is the most common receptor?

Answer 18

The G-protein linked receptor.

Question 19

What is the First Messenger?

Answer 19

The First Messenger is the initial ligand that binds to the receptor.

Question 20

What are Second Messengers?

Answer 20

Second messengers are molecules that start cascades that lead to cellular response.

Question 21

What is the first main way that G-Proteins linked receptors release second messengers?

Answer 21

The first method that G-Proteins use to release second messengers is by first activating the G-protein by giving it GTP, activating adenylate cyclase, converting ATP to cAMP, and then doing something with protein kinases. Responses vary from turning on/off a gene, activating an enzyme, and rearranging the cytoskeleton.

Question 22

What is the second main way that G-Proteins linked receptors release second messengers?

Answer 22

For the second method, G-protein linked receptors first activate a G-protein which then activates the enzyme Phospholipase C, which then breaks down a phospholipid into Inositol triphosphate and diacylglycerol, releasing Calcium Ions (second messengers) in the process. These second messengers activate kinases, which in turn can do things such as turning on/off a gene, activating an enzyme, or rearranging the cytoskeleton.

Question 23

What is Apoptosis?

Answer 23

Apoptosis is cell suicide. So sad. The cell chops up all of its stuff and packs everything up and then all of its remains are digested by scavenger cells.

Question 24

How is Apoptosis useful?

Answer 24

Apoptosis is useful in minimizing damage. Apoptosis is to the multicellular organism as breaking burning buildings is to the Great Fire of London.

Question 25

What do Kinases do?

Answer 25

Kinases bring about changes such as toggling a gene, activating an enzyme, or rearranging the cytoskeleton.

Question 26

What causes Apoptosis?

Answer 26

Apoptosis is caused by protein misfolding, a “Death-signalling ligand” or damage to the DNA in the nucleus of the cell.