Membrane structure

Question 1

What is permeability?

Answer 1

The ability of any material or molecules that is allowed to pass through cell.

Question 2

What the main factors of Biological Membrane Functions?

Answer 2

-Creation of concentration gradients
-pH and ionic differences create electrochemical potentials
-Site for receptor molecule biding for cell
signaling (mostly ligands like hormones)

Question 3

What are the most noticeable things about Phospholipids?

Answer 3

-phospholipids have a polar head and a
non-polar tail
This makes them amphipathic!!!

Question 4

What are Lipid micelles?

Made of phospolipds.

Answer 4

Hydrophilic heads outisde of circle.
Hydrophilic Tails on inside of circle

Question 5

What are Lipid bilayers?

Made of phosolipids?

Answer 5

Hydrophilic heads outisde of I shape .
Hydrophilic Tails on inside of I shapee.

Question 6

What is a Lipsome?

Answer 6

-Sphere composed of a lipid bilayer

Question 7

What are some other components of
Biological Membranes?

Answer 7

-Cholesterol (have hexgan stuctures with CH and HO)
-Proteins
Glycolipids and glycoprotiens (monomer stucture- sphere,has swirly lines going down, has hexgan on side)

Question 8

What is the difference between saturated & unsaturated fatty acids

Answer 8

Saturated fatty acids- all single bonds
between the carbons (Ex. Butter)

Unsaturated fatty acids-double
bonds between the carbons (Ex. Safflower oil)

Question 9

Does Lipid Fluidity Also
Affect Membrane Permeability?

Answer 9

Yes!!!

Question 10

A increase in lipid fluidity means?

Answer 10

increase in membrane permeability

Question 11

What happens when a membrane becomes more fluid?

Answer 11

It also becomes more permeable

Question 12

What happens when a membrane becomes less fluid?

Answer 12

It decreases in membrane permeability

Question 13

What Causes a Decrease Membrane Fluidity?

Answer 13

Saturation of Fatty Acid Chain
– Lengthening of Fatty Acid Chain

Question 14

What Causes an Increase in Membrane Fluidity?

Answer 14

Unsaturation of Fatty Acid Chain
– Shortening of Fatty Acid Chain

Question 15

What does cholesterol do?

fun fact- slightly reduces membrane permeability

Answer 15

1.acts as a “glue” to prevent membranes being too fluid and too permeable at warmer temperatures

2.separates the phospholipids, preventing
them from crystallizing at lower temperatures

High temps means lower cholesterol needed get rid of acess fluid
Low temp means higher cholestrol needed to survive

Question 16

Does Phospholipids have movement?

Answer 16

Yes, they have consistent lateral motion but rarely flip to other side of bilayer.

Question 17

What are some components of Glycolipids & Glycoproteins?

Answer 17

Glycolipids
-On outside of cell
-stretched out hexagons
Glycoproteins are
used in cell-cell
interactions