Cell Biology III and Action Potential

Question 1

What does the cytoskeleton of a neuron consist of?

Answer 1

Microtubules, microfilaments and neurofilaments.

Question 2

How is it called when free ribosomes seem to be attached on a thread?

Answer 2

Polyribosome

Question 3

What is a polymer?

Answer 3

A long strand of small proteins.

Question 4

How is it called when small proteins are enjoined to a long strand?

Answer 4

Polymerization

Question 5

Are a neuron’s membranes of the soma and the axons identical?

Answer 5

No!

Question 6

Does protein synthesis also happen in the axon?

Answer 6

No, just in the soma. There are very few or no free ribosomes and there is no ER in an axon.

Question 7

What are astrocytes?

Answer 7

Glial cells

Question 8

What is one of the functions an astrocytes serves?

Answer 8

Enclosing a synaptic cleft, thereby restricting the spreading of neurotransmitters.

Question 9

How can glial cells influence synaptic activity?

Answer 9

By controlling the blood flow and glucose transport!

Question 10

What glial cells are responsible for the formation of blood-brain-barriers?

Answer 10

Astrocytes

Question 11

In the development of neurons the cell precursor is guided by?

Answer 11

Soluble and stationary signals

Question 12

During the development of a new neuron, what guides the growing axon towards the postsynaptic cell?

Answer 12

Growth factors and stationary signals.

Question 13

Describe the role of adhesion proteins during the development of neurons!

Answer 13

They establish the contact between an axon and what will soon be the postsynaptic neuron. After they established contact a synapse is formed.

Question 14

What does synaptogenesis mean?

Answer 14

The formation of a synapse.

Question 15

Basic function of a finished neuron in four stages:

Answer 15

1. Integration of all synaptic input
2. Due to the integration an action potential is either initiated or not at the axon hillock
3. The action potential runs along the axon and …
4. … triggers transmitter release at the axon terminal.

Question 16

Ion channels allow efflux along …

Answer 16

… concentration gradient.

Question 17

What is reached when there is an equal number of Na+ and Cl- in both compartments?

Answer 17

Electroneutrality

Question 18

What does Cl- stand for?

Answer 18

Chloride

Question 19

What does Na+ stand for?

Answer 19

Sodium

Question 20

What is sufficient to generate an ion equilibrium across a membrane?

Answer 20

Open ion channels

Question 21

What is needed do generate unequal ion distribution?

Answer 21

ATPase

Question 22

What does ATPase do?

Answer 22

It catalyzes the decomposition of Adenosine triphosphate (ATP) into Adenosine diphosphate (ADP).

Question 23

What is the energy used for that is generated by transmembrane ATPase?

Answer 23

To move solutes across the membrane, usually against the concentration gradient.

Question 24

What is a solute?

Answer 24

A solute is a substance dissolved in another substance, known as solvent.

Question 25

How could a sodium/potassium - pump of a membrane also be called?

Answer 25

Na+/K+ ATPase

Question 26

What can be used for “downhill” ion flow across a membrane?

Answer 26

Ion channels

Question 27

What can be used for “uphill” ion flow?

Answer 27

Ion transporters

Question 28

What does “uphill” stand for in relation to ion flow?

Answer 28

Against concentration gradient

Question 29

What are the three possible states of ion channels/transporters?

Answer 29

Open
Closed
Locked Closed

Question 30

What’s the technical term for the mechanism the action potential uses to travel along an axon in myelinated axons?

Answer 30

Saltatory Migration

Question 31

What are neurotransmitters stored in in the axon terminal?

Answer 31

Vesicles