Forces Acting Across Membranes 2 Flashcards Preview

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Flashcards in Forces Acting Across Membranes 2 Deck (12)
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1
Q

What are forces moving water and other molecules driven by?

A

Concentration gradients.

2
Q

Is there a large flux of ions when the channels open?

A

No, but it is enough to change the electrical status of the cell.

3
Q

What does the net effect of 2 electrical charges create?

A

Electrochemical gradient.

4
Q

What are endocytosis and exocytosis?

A

Mechanisms for moving macromolecules without disrupting the membrane.

5
Q

What is the endocytosis mechanism?

A

Invagination of membrane to form a vesicle which separates on the cytoplasmic surface and migrates within the cell to its destination. Example - WBC

6
Q

What is the exocytosis mechanism?

A

Materials are exported out of the cell via secretory vesicles. Example - Neurotransmitters

7
Q

Define diffusion.

A

Process of a gas or substance expanding to fill all the available volume. The substance will spread until the concentration is uniform throughout the whole cell.

8
Q

What is the equation for the magnitude of net flux?

A

F=kpA (c1-c2)

9
Q

What can diffuse through the lipid bilayer?

A

Small, lipophilic, uncharged molecules.

10
Q

Define channels.

A

Act as aqueous rate for diffusion of ions, only allow small mineral ions like sodium to pass.

11
Q

What is the electrochemical gradient?

A

The combination of chemical and electrical gradient

12
Q

Defined facilitated diffusion.

A

Movement of molecules through transport proteins down their electrochemical gradient.