Chapter 12: Axonal transport

Question 1

What is axonal transport?

Answer 1

The two way passage of proteins, organelles, and other materials along an axon

Question 2

What is anterograde transport?

Answer 2

the movement away from the soma down the axon

Question 3

What is retrograde transport?

Answer 3

movement up the axon toward the soma

Question 4

What motor protein is used during anterograde transport?

Answer 4

kinesin

Question 5

What kind of protein is used during retrograde transport?

Answer 5

dynein

Question 6

What are the two types of axonal transport?

Answer 6

fast and slow

Question 7

Fast axonal transport

Answer 7

occurs at a rate of 200 to 400 mm/day and may be either anterograde or retrograde

Question 8

What does fast anterograde transport do?

Answer 8

moves mitochondria; synaptic vesicles; other organelles; components of the axolemma; calcium ions; enzymes such as acetylcholinesterase; and small molecules such as glucose, amino acids, and nucleotides towards the distal end of the axon

Question 9

What does fast retrograde transport do?

Answer 9

returns used synaptic vesicles and other materials to the soma and informs the soma of conditions at the axon terminals. some pathogens exploit this process to invade the nervous system. They enter the distal tips of an axon and travel to the soma by retrograde transport

Question 10

Slow axonal transport

Answer 10

is an anterograde process that works in a stop and go fashion. If we compare fast axonal transport to an express train traveling nonstop to its destination, slow axonal transport is like a local train that stops at every station.

Question 11

What does slow axonal transport do?

Answer 11

it moves enzymes and cytoskeletal components down the axon, renews worn out axoplasmic components in mature neurons, and supplies new axoplasm for developing or regenerating neurons. damaged nerves regenerate at a speed governed by slow axonal transport