Lipids

Question 1

What elements make up lipid molecules

Answer 1

Carbon, hydrogen, oxygen, ( ( and phosphorous for phosphate in phospholipids)

Question 2

What are the 2 main type of lipids

Answer 2

oils → liquid at room temp
Fats → solid at room temp

Question 3

Are lipids polar

Answer 3

Non-polar so immiscible / doesn’t dissolve in water but does in non-polar the other lipids + some organic solvents

Question 4

Function of lipids

Answer 4

Energy source + storage→ 2 x more than carbs + stored in adipose cells → protects delicate organs from physical damage → oxidation of . Triglycendes produces metabolic water

Question 5

Lipid functions pts 2

Answer 5

Phospholipids = important component of all biological membranes → waxes and oils can waterproof leaves ( cuticles) reducing water loss →thermal insulators reducing body heat loss and electrical insulators for nerve cells → some hormones like steroids are lipids

Question 6

Define saturated fatty acids

Answer 6

All carbon atoms joined by single bond → max number of hydrogen atoms per carbon atom → long straight chains with high melting point → animal fats

Question 7

Unsaturated fatty acid

Answer 7

At least one double Carbon bond so don’t have max theoretical hydrogen atoms bonded → plants + form oils → polyunsaturated fats= healthier

Question 8

Structure of triglycerides

Answer 8

One glycerol and 3 fatty acids → after condensation polymerisation reaction 3 ester bonds formed and 3 water molecules removed

Question 9

Structural formula of glycerol → has to be drawn
→ general formula of fatty acid

Answer 9

C3H803
CH3(CH2)nCOOH

Question 10

What are fatty acids

Answer 10

Long molecules with hydrophilic polar end and hydrophobic non-polar tail

Question 11

Components of phospholipids

Answer 11

Glycerol, two fatty acids and one phosphate group

Question 12

Product of lipid hydrolysis

Answer 12

Glycerol and fatty acids

Question 13

Why are lipids used instead of carbs for energy store in seeds and animals

Answer 13

Nearly 2 x higher yield of energy per gram

Question 14

Why are triglycerides non-polar + there fore insoluble in water

Answer 14

Glycerol has hydrophilic polar OH ion + carboxylic group is also polar so hydrophilic group / create ester bond so now hydrophobic because fatty acidsuse hydrophobic → their hydrocarbon chain

Question 15

What happens it person has high intake of saturated fats

Answer 15

Liver produces large amounts of low density (LDL) leading to plaque → atheromas a reduce blood flow, lead to c blood clots and atherosclerosis

Question 16

High intake of unsaturated fats

Answer 16

Liver produces (hdl) high density lipoproteins which remove excess LDL reducing health risks

Question 17

Why does body use lipoproteins

Answer 17

Lipids are insoluble and non-polar so lipoproteins allow them to be transported around body in blood plasma want dissolve otherwise