lipids

Question 1

11 functions of lipids

Answer 1

energy source, water source, energy store , thermal insulation, stores fat soluble vitamins, buoyancy, cushioning , membrame formation , hormone production , waterproofing

Question 2

Function of lipids
buoyancy explanation

Answer 2

• fat is less dense than water
• used by aquatic mammals to help them stay afloat

Question 3

Function of lipids
cushioning explanation

Answer 3

• visceral fat protects organs
• acts as a shock absorber

Question 4

Function of lipids
membrane formation explanation

Answer 4

• creation of hydrophobic barriers
• eg. lipid rich coat formed on bacteria

Question 5

Function of lipids
Electrical insulation explanation

Answer 5

• for impulse transmission
• eg. lipid in nerve cells acts as an electrical insulator

Question 6

Function of lipids
Waterproofing explanation

Answer 6

• eg birds feathers and plants waxy cuticle.
• form of protection for plant / animal

Question 7

Function of lipids
energy source explanation

Answer 7

• can be used in respiration
• twice as much energy released per gram as carbohydrates
• done by hydrolysing the ester bonds, then the glycerol and the fatty acids can be broken down completely.

Question 8

Function of lipids
water source explanation

Answer 8

water is yielded from respiration

Question 9

Function of lipids
thermal insulation explanation

Answer 9

• eg, whale blubber, acts as a heat insulator
• Animals preparing fro hibernation store extra fat

Question 10

Function of lipids
storing fat soluble vitamins explanation

Answer 10

adipose tissues stores vitamins ADE and K

Question 11

made up of elements
what ratio

Answer 11

carbon, hydrogen and oxygen
1:2:<1

Question 12

What state are fats at room temp?

Answer 12

solids

Question 13

what state are oils at room temp

Answer 13

liquids

Question 14

what type of molecules are lipids

Answer 14

• macro molecules
• complex molecules with a relatively large molecular mass
• do not form polymers as they are not monomers

Question 15

what is the distribution of electrons in lipids

Answer 15

even distribution of electrons, so lipids are not polar

Question 16

What is lipids solubility

Answer 16

• insoluble in water because they do not attract water molecules
• do dissolve in alcohol

Question 17

Triglyceride structure

Answer 17

made by combining one glycerol molecule to three fatty acids

Question 18

What is the structure of glycerol

Answer 18

look up

Question 19

What is the structure of fatty acids

Answer 19

look up

Question 20

What group is glycerol part of

Answer 20

• alcohol group
• acts as backbone of the macro molecule

Question 21

What group are fatty acids

Answer 21

• part of carboxylic acids due to carboxyl group (COOH) with a hydrocarbon chain attached

Question 22

Formation of triglycerides

Answer 22

• The hydroxyl groups interact leading to the formation of three water molecules and three ester bonds between the fatty acids and glycerol molecules
• condensation reaction

Question 23

saturated fats, bonding and structure

Answer 23

• no double carbon bonds
• all carbons have formed the max amount of bonds (4) with hydrogen
• straight chain is produced
• fatty acid chains can be packed closely together

Question 24

unsaturated fats, bonding and structure

Answer 24

• double bonds between one or more carbon
• only one double carbon bond - monounsaturated
• two or more double carbon bonds - polyunsaturated
• double bonds causes kinks/ bends
• fatty cannot be packed densely together

Question 25

relationship between fats and CHD

Answer 25

Research is inconclusive, no accepted idea
- some evidence points towards an excess of saturated fats in diet can lead to CHD
- an excess of any fat, leads to obesity which will put a strain on the heart

Question 26

Why are triglycerides ideal energy storage molecules?

Answer 26

• insoluble
• releases twice as much energy as carbohydrates per gram
• do not effect water potential of cell