Lipids And Membranes Osmosis

Question 1

List some properties of lipids

Answer 1

Made up of C,H and O 
Macromolecules 
They are insoluble in water 
Dissolve in ethanol 
Good energy source 
Poor conductor heat and electricity

Question 2

List some functions of lipids

Answer 2

Component of cell membranes 
Protection of vital organs 
Water proofing, to prevent evaporation 
To thermally insulate the body 
For electrical insulation, forming the myelin sheath around some neurones 
As a water source

Question 3

Testing for lipids

Answer 3

1. Break up small sample into a test tube with a glass rod. Add approx 2cm3 of ethanol mix well with glass rod
2. Put approx 2cm3 of distilled water in a test tube
3. Pour ethanol from first test tube into the body water in the second test tube and invert it to mix
   Milky white emulsion forms lipid is present

Question 4

Triglyceride:-
Formed by?
Molecules?
Bond?

Answer 4

Formed by a condensation reaction between a Glycerol and 3 fatty acids

Question 5

Draw how a triglyceride is formed

Answer 5

Remove the H20

Called esterification

Question 6

Draw fluid mosaic model

Answer 6

Phospholipid bilayer with embedded proteins.
Glycoproteins and glycolipids involved in cell recognition and signalling
Cholesterol

Question 7

Functions of the plasma membrane

Answer 7

Partially permeable membrane
Selectively permeable
Cell recognition
Cell signalling

Question 8

Movement of molecules across the plasma membrane list?

Answer 8

Simple diffusion
Facilitated diffusion
Active transport
Endocytosis and exocytosis

Question 9

Define diffusion

Answer 9

The passive movement of molecules from an area of high concentration to an area of low concentration until an equilibrium is reached

Question 10

Define osmosis

Answer 10

The diffusion of water from an area of higher water potential to an area of lower water potential, through a partially permeable membrane

Question 11

What is a isotonic solution
What is a hypotonic solution
What is a hypertonic solution

Answer 11

Where there is no net movement of water
Water may enter the cell
Water may leave the cell

Question 12

Percentage change equation

Answer 12

Change = (change/original)x100

Question 13

What is facilitated diffusion?

Answer 13

A passive process where substances pass through a carrier protein, down a concentration gradient e.g amino acids, glucose