Lipids

Question 1

What makes up lipids

Answer 1

Carbon oxygen and hydrogen

Question 2

*Describe and explain how the structure and properties of different carbohydrate and lipid molecules suit them to their role as energy storage molecules in plants and animals.

Answer 2

Both = (carbs are large molecules) - insoluble = don’t affect water potential or cell

Carbs:
- polymers of glucose = glucose used in respiration to release energy

• 1-4 glycosidic bonds = easy to make + break to release glucose
• compact = take up less space in cell

Lipids:

• fatty acids are long carbon chains = can be broken down to release 2 carbons
• animal fats saturated/harder = role in protection as well as energy storage

Question 3

Solubility of lipids

Answer 3

Insoluble in water = because they are non polar
• soluble in organic solvents
• hydrophobic

Question 4

Triglycerides formation

Answer 4

3 fatty acids + 1 glycerol

Question 5

Do lipids form polymers

Answer 5

NO

Question 6

Difference between fats and oils

Answer 6

Fats = solid at RT // oils = liquid at RT

Question 7

What type of molecule are lipids

Answer 7

Macromolecules

Question 8

What are the functions of lipids [6]

Answer 8

• primary source of energy
• energy store
• insulation
• buoyancy
• protection

Question 9

Glycerol

Answer 9

Question 10

Fatty acids

Answer 10

Hydrocarbon chain + top is a carboxylic acid (COOH)

Question 11

Bonding between glycerol and fatty acid

Answer 11

Ester bond

Question 12

Saturated fats example

Answer 12

Margarine

Question 13

Unsaturated fats example

Answer 13

Oil

Question 14

Diff between saturated and unsaturated fats

Answer 14

Unsaturated fats have a double carbon bond

Question 15

Unsaturated fats effect on melting point

Answer 15

the more unsaturated fats you have, the lower the melting + boiling point because the bond creates a kink causing the molecules to be pushed slightly apart, hence they are more fluid

Question 16

Phospholipid structure

Answer 16

head -made of glycerol and a phosphate
2 fatty acids = tails
^= can be saturated or unsaturated

Question 17

Phospholipids hydrophilic and hydrophilic ends

Answer 17

Head = hydrophilic
Fatty acid tails = hydrophobic

Question 18

Amphipathic

Answer 18

Hydrophilic and hydrophobic

Question 19

Function of phospholipids

Answer 19

Makes up plasma membrane

Question 20

How are triglycerides made

Answer 20

Question 21

Functional group of glycerol

Answer 21

Alcohol

Question 22

Functional group of fatty acids

Answer 22

Carboxylic acid

Question 23

What else does glycerol + three fatty acids produce in a condensation reaction

Answer 23

3 water molecules

Question 24

What is the name when the lipid has 1 double bond

Answer 24

Mono saturated

Question 25

What is the name when the lipid has 2+ double bonds

Answer 25

Poly saturated

Question 26

Are phospholipids soluble in water?

Answer 26

Yes

Question 27

Why are phospholipids soluble in water

Answer 27

Have extra electrons = soluble in water

Question 28

Sketch the chemical structure of a phospholipid

Answer 28

Question 29

Significance of phospholipids forming bilayers

Answer 29

• Able to separate an aqueous environment in which cells usually exist from the aqueous cytosol within

Question 30

Phospholipid bilayer

Answer 30

Hydrophilic phosphate head
Hydrophobic fatty acid tails repelled by water
Head forms hydrogen bonds w water
Hydrophobic nature of tails results in their facing towards each other so bilayer forms

Question 31

Micelle

Answer 31

tiny ball formation when phospholipids dropped in water (heads on outside, tails on inside)

Question 32

Cholesterol structure + what it is

Answer 32

Carbon, hydrogen, oxygen
Bulky molecule
Steroid attached to an alcohol

Question 33

Cholesterol function in phospholipid Bilayer

Answer 33

cholesterol can sit in between the tails to reduce fluidity in phospholipid bilayer membrane”

Question 34

What is cholesterol used to make

Answer 34

used to mahe steroid hormones = sexhormones and
vitamins

Question 35

Answer 35

Question 36

Answer 36

Question 37

Answer 37

Question 38

Answer 38