Cell membrane

Question 1

Cell membrane review –> structure and function

Answer 1

Structure
Bilayer of phospholipids with proteins embedded within it
Fluid and flexible layer
Phospholipid
Hydrophilic head
Hydrophobic tail
Function
Regulates the passage of materials in and out of the cell

Question 2

Fluid Mosiac Model (what are the 4 main functions?)

Answer 2

The idea that a biological membrane consists of a fluid phospholipid bilayer in which proteins are embedded and float freely!

4 Main Functions:
Transport
Enzymatic Activity
Triggering Signals
Attachment & Recognition

Question 3

Phospholipid bilayer transport

Answer 3

phospholipid structure
polar head (phosphate) - attracted to water, water soluble
non polar tail (2 fatty acids) - repels water
this makes a water barrier in the middle to control the movement of water in and out
held together by weak intermolecular forces, allows for movement of molecules in membrane (hydrogen bonding, hydrophobic interactions)

Question 4

Imbedded protiens (what are the 2 types?)

Answer 4

2 Types:

integral proteins- imbedded through the membrane- involved in movement of materials into and out of the cell

peripheral proteins- stick out of the inside layer- connect the cytoskeleton

Question 5

glycolipids and glycoprotiens

Answer 5

stick out of the outside membrane layer

glycoprotein: protein with a carbohydrate stuck to it, enables cells to recognize each other

glycolipid: lipid with a carbohydrate stuck to it

provide stability and mobility by reacting to temperature

Question 6

fluid mosiac model –> cholesterol

Answer 6

KEEPS EVERYTHING TOGETHER
Embedded with the phospholipid bilayer

Influence membrane fluidity (act as stabilizers)

At higher temperature, increases intermolecular forces, holds membrane together

At lower temperature, prevents phospholipids from solidifying into a gel, keeps membrane fluid