Macronutrients - lipids

Question 1

define hydrophobic

Answer 1

repels water/ doesn’t like water

Question 2

define hydrophilic

Answer 2

attracted to water

Question 3

what is adipose tissue? and where is it found?

Answer 3

fat cells
under skin and around organs

Question 4

what are some of the characteristics of lipids?

Answer 4

-contains C,H and O but unlike carbohydrates lipids have a lot less oxygen
-non polar molecules so insoluble in water
-soluble in organic solvents

Question 5

what are some types of lipids?

Answer 5

1. triglycerides
2. phospholipids
3. other lipids eg hormones, cholesterol and waxes

Question 6

what is the structure of a saturated fatty acid and where are they most commonly found?

Answer 6

• hydrocarbon chain has only single bonds,lies flat on top of each other
• animals fats are saturated and are solid

Question 7

what is the structure of a unsaturated fatty acid and where is it commonly found?

Answer 7

• hydrocarbon chain consists of at least one carbon-carbon double bond and has a kink due to that so doesn’t lie flat
• most found in plant fats, liquid

Question 8

what makes up a triglyceride?

Answer 8

glycerol and 3 fatty acids

Question 9

how is a triglyceride formed?

Answer 9

a condensation reaction occurs between the carboxyl group from the fattu acids and the hydorxyl groups of the glycerol forming an ester bond.
glyceride molecule is always the same but fatty acids vary

Question 10

what are some functions of triglycerides?(5)

Answer 10

-energy source and metabolic water source
-far as a buoyancy aid, fat is stored as adipose tissue
-heat insulation
-waterproofing for hair or feathers
-nervous systems

Question 11

what makes a cell membrane?

Answer 11

phospholipid layer

Question 12

why is glucose used for energy before lipids are?

Answer 12

it requires far more energy to break down lipids than glucose

Question 13

what are the two similarities between triglycerides and phospholipids? 3 differences?

Answer 13

1. both have glycerol
2. both have ester bonds
3. T has 3 fatty acids, P has 2
4. T has no phosphate group, P has a phosphate group
5. T is a non-polar molecule (completely hydrophobic), P has a polar head and non-polar tail (head is hydrophilic and tails are hydrophobic)

Question 14

what is coronary heart disease?

Answer 14

build up of lipids in the coronary arteries

Question 15

how does coronary heart disease occur?

Answer 15

• saturated fat raises the low density lipoproteins (LDL)
• which results in the LDL carrying cholesterol from the liver to the blood/tissues
• which increases the cholesterol in blood
• which increases the chance of atheromas forming leading to heart disease

Question 16

what are the effects of the build up of plaque in the coronary arteries?

Answer 16

bp rises
oxygen starvation to the cardiac muscles

Question 17

how does unsaturated fat affect the coronary arteries?

Answer 17

• unsaturated fat raises high density lipoproteins (HDL)
• which results HDL carrying cholesterol from blood to liver
• whihc decreases cholesterol in blood
• which decreases the chance of atheromas forming
• which reduces risk of heart disease