Lipids And Membrane Stuff

Question 1

Describe the composition of a fatty acid

Answer 1

Unbranched hydrocarbon tail with a carboxyl group at one end

Question 2

What are the 2 types of fatty acids?

Answer 2

Saturated and Unsaturated

Question 3

Describe a saturated fat

Answer 3

• all single bonds
• straight
  
  • pack together well

Question 4

Describe an unsaturated fat

Answer 4

• at least one double bond
• bent shape
  - do not pack together well

Question 5

What are the two carbon-carbon double bond configurations?

Answer 5

Cis and Trans

Question 6

Which of the double bonds have a stronger kink?

Answer 6

Cis

Question 7

Describe a cis double bond

Answer 7

Causes a V shape

Question 8

Describe a trans double bond

Answer 8

Causes a smaller diagonal kink

Question 9

What does changing cis to trans double bonds do to melting point?

Answer 9

Increase melting temperature

Question 10

Describe a phospholipid

Answer 10

Hydrophilic head with a phosphate group and two hydrophobic hydrocarbon tails with one having a double bond

Question 11

Is lipid mobility within each leaflet high or low?

Answer 11

High

Question 12

Is lipid mobility between leaflets high or low?

Answer 12

Very low

Question 13

What enzymes flip lipids to the other side of the membrane?

Answer 13

Phospholipid translocator or flipases

Question 14

What is FRAP?

Answer 14

Fluorescence recovery after photobleaching

Question 15

What does FRAP show?

Answer 15

Diffusion within the plane (shown by a laser bleaching an area of the cell and then you can see fluorescence return to the area because of diffusion)

Question 16

What is an integral protein?

Answer 16

Proteins that are embedded in the membrane

Question 17

What is a peripheral protein?

Answer 17

A protein that lays on the lipid membrane and next to another protein

Question 18

What is a lipid-anchored protein?

Answer 18

A protein that has lipid tails to latch itself into the membrane

Question 19

What are the three transmembrane domains?

Answer 19

• single alpha helix
• multiple alpha helices
• beta barrel

Question 20

What type of residues do protein segments within the biolayer have?

Answer 20

Non polar

Question 21

What is the fluid mosaic model of cell membranes?

Answer 21

The phospholipid bilayers are in a fluid phase with proteins dispersed throughout with constant motion with lipids and proteins alike (besides those that are anchored)

Question 22

What is passive transport?

Answer 22

Movement down a gradient

Question 23

What is osmosis?

Answer 23

Diffusion of water across the membrane

Question 24

What causes Hypertonic conditions?

Answer 24

Adding too much solute out the cell (causes shriveling)

Question 25

What causes isotonic conditions?

Answer 25

Having equal solute concentrations in and out of the cell

Question 26

What causes hypotonic conditions?

Answer 26

Too little solute on the outside, causes cell to lyse

Question 27

What do channel proteins and carrier proteins do?

Answer 27

Facilitated diffusion (Carrier proteins can be active or passive)

Question 28

What are uniport, symport, and antiport?

Answer 28

Uniport - sends stuff one way symport - sends things the same way Antiport - sends stuff opposite ways

Question 29

Does active transport move things up or down a electrochem gradient?

Answer 29

Up

Question 30

What is direct active transport?

Answer 30

Straight up pumping something in or out

Question 31

What is indirect active transport?

Answer 31

Think the proton pump im the ETC, using an active transport created gradient to ride something else in

Question 32

What does the sodium potassium pump use?

Answer 32

Direct active transport (pumps 3 Na+ out, pumps 2 K+ in)

Question 33

What does the sodium glucose symport ear use?

Answer 33

Indirect active transport (sodium is brought in with the echem gradient to pump in glucose)