Test 1 - Neural Signaling

Question 1

What 2 cytoskeletal components allow for vesicle trafficking in cells?

Answer 1

the “roads” are actin & microtubule

Question 2

What motor proteins are associated with each of these 2 cytoskeletal components?

Answer 2

1. Actin: myosin (+/-)
2. Microtuble: kinesin (+) or dynein (-)

Question 3

When considering dendritic spines, dendrites, axons, and ends of axons, explain which cytoskeletal components you would find in each. Are they oriented in the way you would expect?

Answer 3

1. Dendrite - double directions because of placement of organelles and protein production (microtubules)
2. Dendritic spines - actin filaments
3. Axons - microtubules one way (toward +)
4. End of axons: actin

Question 4

Transcytosis

Answer 4

when a protein is targeted to a plasma membrane of one compartment (axon/dendrite), and then is endocytosed and trafficked to a final destination

Question 5

What is the evidence for protein production by dendrites?

Answer 5

1. ribosomes
2. polyribosomes
3. mRNAs detected
4. ER, Golgi apparatus-like organelles

Question 6

Which end goes a way from nucleus which end goes towards?

Answer 6

1. away from nucleus - plus end
2. towards the nucleus - minus end

Question 7

Active transport

Answer 7

Uses ATP - goes against gradient - always requires helper proteins

Question 8

Passive transport

Answer 8

No ATP- goes down concentration gradient (high to low) - sometimes helper proteins

Question 9

Explain what chemical and electrical gradients are and how they work together

Answer 9

chemical - basically a charged ion - basically diffusion
electrical - membrane has a charge the + ion on the outside is attracted to the - charge of the plasma membrane
Both - additive effect of both - increases ion movement - if fighting against the electrical gradient it decreasess ion movement

Question 10

Coupled transport

Answer 10

2 active transporters side by side one uses ATP and has a by-product that activates the other without the use of ATP (symporter & antiporter) - beneficial because it reduces the amount of energy

Question 11

Membrane potential

Answer 11

the electrical difference between the inside of the cell & extracellular environment

Question 12

Depolarization

Answer 12

a change in the electrical potential inside the cell toward a less negative value

Question 13

Hyperpolarization

Answer 13

change in the electrical potential inside the cell toward a more negative value