Cell Transport

Question 1

What is passive transport?

Answer 1

• movement down the force
• no energy required
• downhill

Question 2

What is active transport?

Answer 2

movement against the force

Question 3

Name 2 characteristics of chemical driving forces.

Answer 3

• The gradient “pushes” particles from higher to lower concentration areas
• Force acts from higher to lower concentration areas

Question 4

What is Concentration gradient (ΔC)?

Answer 4

Difference in particle concentration between the inside and outside of the cell

Question 5

Describe the direction of chemical driving forces.

Answer 5

• Down the chemical gradient

- From higher to lower concentration

Question 6

Define cation.

Answer 6

particle with a positive (+) charge

Question 7

Define anion.

Answer 7

particle with a negative (-) charge

Question 8

What are the 3 types of passive transport?

Answer 8

• Simple diffusion
• Facilitated diffusion
• Diffusion through channels

Question 9

Describe simple diffusion.

Answer 9

• passive

- through the lipid bilayer

Question 10

Simple diffusion is influenced by:

Answer 10

• Surface area
• Permeability
• Concentration gradient

Question 11

Give 2 examples of facilitated diffusion.

Answer 11

• GLUT4 insertion: primary exercise effect

- GLUT4 activity (intrinsic): secondary exercise effect

Question 12

Name 3 characteristics of diffusion through channels.

Answer 12

• Transmembrane protein
• Passageway or pore (Aquaporin)
• Substance specific

Question 13

Describe aquaporin channels.

Answer 13

• Selective pores that permit water movement by diffusion
• Urinary system
• Hormonal influence

Question 14

Name 3 types of ion channels.

Answer 14

• Leak channels
• Gated channels
• Bidirectional

Question 15

Describe leak channels.

Answer 15

Allow Na+ and K+ to move down conc. Gradients to maintain stable resting membrane potential

Question 16

Describe gated channels.

Answer 16

Chemical messenger binds, then channel allows ion through

Question 17

Describe bidirectional channels.

Answer 17

Allows movement of ions in both directions

Question 18

Where does primary active transport get it’s energy?

Answer 18

• energy requiring

- usually from ATP hydrolysis

Question 19

Describe ATP hydrolysis.

Answer 19

• Water breaks down ATP
• Liberates phosphate, energy
• Energy used to drive the pump

Question 20

Give an example of primary active transport.

Answer 20

Sodium potassium pump is AKA ATPase

Question 21

Where does secondary active transport get it’s energy?

Answer 21

• Energy released from ion diffusion
• Energy used to drive a pump
• Diffusion due to previous active transport of an ion

Question 22

What is symport?

Answer 22

Moving things together in one direction

Question 23

What is antiport?

Answer 23

one goes in, one goes out. Opposite directions.

Question 24

What is osmolarity?

Answer 24

Drives movement of substances into capillary bed and v.v

Question 25

What is iso-osmotic?

Answer 25

- balanced | - All we need is a difference across the membrane to move it

Question 26

What is hyper osmotic?

Answer 26

- high solute concentration means low water concentration - Hyperosmotic inside cell, water will move inside the cell - Moving down concentration gradient, even if it is against pressure

Question 27

What is hypo osmotic?

Answer 27

High water, low solute concentration

Question 28

What is osmotic pressure?

Answer 28

- Total solute concentration | - Determines the pull on water

Question 29

When solute concentration increases, osmotic pressure ______.

Answer 29

increases

Question 30

Give an example of solute concentration affecting osmotic pressure.

Answer 30

- Total solute concentration: kidneys, urinary system - Long loop of Henley: dips far down into centre of kidney, salty = high concentration of solutes in medulla of kidney - Water is pulled out of tubule into the medulla = concentrates urine

Question 31

What is transcytosis?

Answer 31

moving something across the cell

Question 32

Define endocytosis.

Answer 32

bringing something into the cell

Question 33

Define exocytosis.

Answer 33

moving something out of the cell.