Membrane Transport - BIO 102 CONTENT

Question 1

What are the two major forms of membrane transport?

Answer 1

• Passive Transport (no energy)
• Active Transport (Requires energy)

Question 2

Passive Transport

Answer 2

• No chemical energy required
• Movement of substances across membranes down its electrochemical gradient

Question 3

Simple Diffusion

Answer 3

• Movement of substances from an area of high concentration to an area of low concentration
• Called movement “down a concentration gradient”
• Diffusion is only useful over short distances

Question 4

Electrochemical gradient

Answer 4

Diffusion gradient of an ion influenced by ion concentration and membrane potential

Question 5

In living organisms what molecules use simple diffusion?

Answer 5

• Small, uncharged, non-polar molecules
• Like oxygen and carbon dioxide

Question 6

Facilitated Diffusion

Answer 6

• Diffusion across a membrane at a faster rate
• This is due to the assistance from transport proteins

Question 7

What are the two types of transport proteins involved in facilitated diffusion?

Answer 7

• Channel Proteins
• Carrier Proteins

Question 8

Channel Proteins

Answer 8

• Have a tunnel-like shape that allows charged molecules and ions to pass through
• Hydrophilic channel
• Can be gated channels

Question 9

Carrier Proteins

Answer 9

• Transport uncharged molecules
• Bind to molecules and transport them across a membrane
• Alter their shape in the process

Question 10

Osmosis

Answer 10

• The diffusion of water, across a membrane

Question 11

Osmotic Pressure

Answer 11

• Pressure created by water molecules as they try to reach equilibrium across a membrane

Question 12

Turgor Pressure

Answer 12

• Outward pressure on the cell wall exerted by water in the vacuole of a plant cell

Question 13

Plasmolysis

Answer 13

• Shrinkage of the cell membrane away from the cell wall, due to the loss of water
• Causes plants to wilt