Cell Membranes

Question 1

Membrane function

Answer 1

Protect the cell
Controls the content of the cytoplasm
Senses molecules and other cells in the environment

Question 2

Selectively permeable
Fluid mosaic
Bind to cytoplasm and extracellular matrix

Answer 2

Cell membranes

Question 3

Phospholipids

Answer 3

Primary molecules that make up biological membranes.

• phosphate containing hydrophilic head
• hydrophobic lipid tail.

Question 4

Amphipathic

Answer 4

A molecule containing both hydrophobic and hydrophilic regions

Question 5

Phospholipid bilayer

Answer 5

2 large phospholipids
Arranged with the hydrophilic heads facing outwards
Hydrophobic tails facing inwards

Question 6

Micelle

Answer 6

Forms spontaneously because it is the most energetically stable structure.
Ensures the hydrophobic regions face away from water

Question 7

Animal cell membrane structure

Answer 7

• Phospholipids bilayer include sterols
• bilayer separates 2 aqueous regions- extracellular and intracellular
• proteins embedded in bilayer
• carbohydrates are attached to the exterior of the membrane

Question 8

Carbohydrates

Answer 8

Hydrophilic
Located on the outside of the membrane
Bound to a membrane embedded molecule
Generates a wide variety of cellular messages

Question 9

Glycoprotein

Answer 9

Carbohydrate bound to a protein on the outside of the cell membrane

Question 10

Glycolipid

Answer 10

Carbohydrate bound to a lipid on the outside of the cell membrane

Question 11

Sterols

Answer 11

Help membranes maintain fluidity and stability
Prevent membrane from solidifying at low temperatures
Hinder phospholipid movement in the membrane at moderate temperatures

Question 12

Cell membrane exceptions to the rule

Answer 12

Psychrophilic organisms
Termophilic organisms
Mesophilic organisms