Topic 1 - Cell Membrane + proteins

Question 1

Cell membrane

Answer 1

Is a phospholipid membrane that surrounds a cell or its organelles

Question 2

Function of cell-surface membrane

Answer 2

Cell surface membrane is a plasma membrane function:

Separate internal and external environment of cell

Control what can enter and exit the cell

Question 3

Phospholipids

Answer 3

Amphipathic they have Polar and nonpolar regions

Polar head which is hydrophilic (loves water)

Non polar Fatty acid tails which are hydrophobic (water hating)

Question 4

Phospholipid bilayer in the membrane function

Answer 4

Allows lipid soluble (nonpolar) molecules to move through eg lipid based hormones (steroids) and gases

Prevent water soluble (polar) molecules from entering e.g. glucose ions

Make the membrane flexible and self heating

Question 5

Proteins

Answer 5

A inspersed through the membrane

Question 6

Intrinsic Proteins

Answer 6

Span the cell membrane

They can be protein channels or carrier proteins

They transport specific polar molecules: ions glucose and amino acid’s

Question 7

Extrinsic proteins

Answer 7

Okay on the surface of the phospholipid bilayer

They can be stand alone proteins

Sometimes they are associated with carbohydrates to form glycoproteins

Question 8

Glycoproteins

Answer 8

Cell recognition – antigens

Health cells attached to one another and form tissue – mechanical strength

From receptor site for hormones or neurotransmitters

Question 9

Glycolipids

Answer 9

Are carbohydrates covalently bonded to lipids they are extended from phospholipid bilayer’s

Cell recognition – antigens

Help cells attached to one another and form tissues – mechanical structure

Question 10

Cholesteryl

Answer 10

A type of lipid so hydrophobic
They pull together the fatty acid tales of phospholipids

Reduce lateral movement of phospholipids and other molecules

Acts as a perfect temperature changes maintains membrane fluidity

Prevent water and ion leakage