fatty acids and triglycerides

Question 1

what type of molecule is a lipid

Answer 1

macromolecule which contains elements carbon, hydrogen, oxygen.

Question 2

are lipids soluble in water

Answer 2

no insoluble as not polar but do dissolve in alcohol.

Question 3

Three lipid molecules should know

Answer 3

1)Triglycerides
2)Phospholipids
3)Cholesterol

Question 4

what type of molecule is a triglyceride

Answer 4

-macromolecule
-formed from 1 glycerol and 3 fatty acid molecules joined by ester bond

Question 5

is the glycerol in a triglyceride always the same

Answer 5

yes

Question 6

are the fatty acids in glycerol always the same

Answer 6

-no, there is 100s of fatty acids,
-made up of a carboxyl group with hydrocarbon tail

Question 7

what can a hydrocarbon tail be

Answer 7

saturated or unsaturated and can vary in length

Question 8

what is the difference between a saturated and unsaturated tail

Answer 8

-saturated all C-C bond are single
-Unsaturated at least one C=C double bonded

Question 9

what is the bond between a glycerol and fatty acid

Answer 9

an ester bond

Question 10

what is a glycerol made of

Answer 10

3 carbon alcohol molecule

Question 11

what is an ester bond

Answer 11

formed when organic acid joins to alcohol molecule via condensation reaction

Question 12

how long can the hydrocarbon tail be

Answer 12

2-20 carbons long and represented by R

Question 13

how are triglycerides synthesised

Answer 13

-Both glycerol and fatty acids contain hydroxyl groups
-The groups interact leading to formation of 3 water molecules and bonds between glycerol and fatty acids
-this process is called esterification

Question 14

what is a esterification reaction an example of

Answer 14

a condensation reaction

Question 15

how can you reverse the reaction used to from a triglyceride

Answer 15

3 water molecules need to be supplied to reverse it

Question 16

what is the reversal of a triglyceride formation reaction an example of

Answer 16

a hydrolysis reaction

Question 17

in a fatty acid the R group hydrocarbon tail is what

Answer 17

variable

Question 18

what is a hydrocarbon

Answer 18

chain of carbon atoms bonded together with hydro atoms bonded on each side of carbon

Question 19

where are phospholipids present

Answer 19

in all bio membranes

Question 20

what do phospholipids have a similar structure to

Answer 20

triglycerides but fatty acids replaced by phosphate group

Question 21

what type of reaction is required to make a phospholipid

Answer 21

A condensation reaction

Question 22

how is the ester bond formed in a phospholipid

Answer 22

reaction between OH group on a phosphoric acid and one of three -OH groups on glycerol form ester bond

Question 23

what are the fatty acids in a phospholipid like

Answer 23

-even number (usually 16/18)
-usually one chain saturated other unsaturated

Question 24

how is a phospholipid formed

Answer 24

inorganic phosphate ions in cytoplasm negatively charged (extra electrons). This ion replaces fatty acid in triglyceride making phospholipid.

Question 25

is the fatty acids in a phospholipid hydrophobic or hydrophilic

Answer 25

hydrophobic

Question 26

is the phosphate in a phospholipid hydrophobic or hydrophilic

Answer 26

hydrophilic

Question 27

what is functions of lipids

Answer 27

-membrane formation
-hormone production
-electrical insulation
-waterproofing

Question 28

how are triglycerides energy sources

Answer 28

-broken down in respiration to release energy/generate ATP

Question 29

how are triglycerides broken down to be used as an energy source

Answer 29

hydrolyse ester bonds, then means both glycerol and fatty acids can be broken down to Co2 and H2O.

Question 30

what produces more energy? sugar or a lipid

Answer 30

lipid produce more energy than when sugar respired