lipids

Question 1

what are the 5 important lipid structures?

Answer 1

fatty acid, glycerol, triglyceride,phospholipid, cholesterol

Question 2

describe the structure of a molecule of glycerol

Answer 2

-3 carbons bonded to OH on the right
-all remaining bonds are connected to H

Question 3

describe the structure of a fatty acid

Answer 3

-carboxyl group=final carbon double bonded to O and bonded to OH
-hydrocarbon chain= series of carbons atoms bonded to each other and to H

Question 4

difference between a saturated and unsaturated fatty acid

Answer 4

saturated-single bonds between carbons (bonds are maxed out)
unsaturated-contains double bonds between carbons

Question 5

how is a triglyceride formed?

Answer 5

-3 fatty acids and a molecule of glycerol
-OH on fatty acid and H on glycerol are removed as (3) water molecule, leaving just O molecule
-ester bond formed via condensation reaction

Question 6

functions of triglycerides

Answer 6

-energy source for aerobic respiration
-thermal insulation eg.polar bears
-electrical insulation eg.myelin sheath
-buoyancy eg.seals
-physical protection of organs

Question 7

are saturated/unsaturated fatty acids healthier?

Answer 7

unsaturated as they contain less hydrogen
saturated have no double bonds, so increase cholesterol, not good for us

Question 8

what is a phospholipid composed of?

Answer 8

-phosphate head, and molecule of glycerol (hydrophilic head) and 2 fatty acid tails (hydrophobic tails)
-1 fatty acid is saturated, the other is unsaturated (creates kink)
-ester bond

Question 9

what is the phosphate group?

Answer 9

PO4³‐

Question 10

functions of phospholipids

Answer 10

-main component of cell membraned-lipid soluble molecules can diffuse through membrane by diffusion eg oxygen
-disallows diffusion of polar molecules
-phospholipids form bilayer with hydrophilic heads on outside and hydrophobic tails on inside

Question 11

function of cholesterol

Answer 11

-regulates membrane fluidity
-is a lipid that is part of the membrane
-regulates distance and movement between phospholipids
-more cholesterol=less fluid
-binds to fatty acid tails to increase stability
-used to make steroid hormones and bile

Question 12

why are triglycerides good energy stores?

Answer 12

-energy rich
-insoluble so no impact on water potential