Membranes

Question 1

Membranes

Answer 1

All cell organelles also contain membranes

Plasma membrane
Selectively permeable

Contents:

1. ) lipids
2. ) mostly as 2 layers of phospholipids

Question 2

Lipids

Answer 2

40-80% of the entire membrane is made of ______

Function:

1. ) structure
2. ) regulation

Contents: 
1.) phospholipids 
        Glycerophosholipids 
        Sphingophospholipids 
2.) cholesterol

Question 3

Phospholipids

Answer 3

Are amphipathic

Movement:

1. ) flexion
2. ) rotation
3. ) lateral movement
4. ) Migration from 1 leaflet to another

Question 4

Phospholipid bilayer

Answer 4

Polar heads point outward

1. ) towards exterior= outer leaflet
2. ) toward interior = inner leaflet

Fatty acid tails point towards middle

Question 5

Sphingomyelin

Answer 5

Sphingosine+fatty acid+ phosphate+ choline

In the plasma membrane of all animal cells

highly concentrated in myelin sheath of nerves

Question 6

Cholesterol

Answer 6

Hydroxyl group on _______ faces same direction as polar head

_______ decreases motion of phospholipids ( this increases rigidity and strength)

Question 7

Lipid rafts

Answer 7

Cholesterol-rich microdomains

Function:

1. ) cholesterol transport
2. ) endocytosis
3. ) signal transduction

Types:

1. ) glycosphingolipid-enriched membranes
2. ) phosphatidylinositol-rich
3. ) calveolae

Question 8

Glycolipids/glycocalyx

Answer 8

Lipids+Sugars

Function: Cell-cell interactions

Question 9

Membrane Proteins

Answer 9

Function:

1. ) cell adhesion molecules
2. ) ion channels
3. ) transport proteins
4. ) ligand receptors
5. ) G proteins: binds GTP for cell signaling in response to a hormone