lipids

Question 1

structure of a triglyceride

Answer 1

one glycerol molecule
three fatty acid chains coming off of it

Question 2

structure of a phospholipid

Answer 2

one glycerol molecule
two fatty acid chains coming off it
a phosphate group is attached to the glycerol mol

Question 3

how are triglycerides formed?

Answer 3

via condensation reaction between one mol of glycerol and 3 mol of fatty acids = ester bond

Question 4

describe the triglyceride formation

Answer 4

condensation between glycerol and fatty acid
ester bond
1 water molecule released for every ester bond formed
-in total3 mol lost

Question 5

what kind of structure do the fatty acids have in a triglyceride?

Answer 5

saturated and unsaturated

Question 6

what is a saturated acid?

Answer 6

the hydrocarbon chain has only single bonds between carbons
-no double bonds
-holding max amount of hydrogens
- more likely solid at room temp

Question 7

what is an unsaturated acid?

Answer 7

the hydrocarbon chain consists of at least one double bond between carbons
- monounsaturated = 1 double bond
- polyunsaturated = number of double bonds
- more likely liquid at room temp

Question 8

properties of triglycerides
ENERGY STORAGE

Answer 8

1. Due to the large ratio of energy-storing carbon-hydrogen bonds compared to the number of carbon atoms , a lot of energy is stored in the mol

Question 9

properties of triglycerides
WATER SOURCE

Answer 9

2. Due to the high ratio of hydrogen to oxygen atoms they act as a metabolic water source. Triglycerides can release water if they are oxidised. Essential for animals in the desert like camels

Question 10

properties of triglycerides
WATER POTENTIAL

Answer 10

3. Triglycerides do not affect water potentials and osmosis. This is bc they are large and hydrophobic, making them insoluble in water.
   form droplets

Question 11

properties of triglycerides
MASS

Answer 11

Lipids have relatively low mass
a lot can be stored without increasing the mass and preventing movement

Question 12

property of phospholipids
hydrophilic head

Answer 12

the phosphate group has a negative charge, attracts water repel lipids

Question 13

property of phospholipids
hydrophobic tails

Answer 13

the fatty acid chains repel water, able to mix with other lipids

Question 14

what does the hydrophilic head and hydrophobic tails create?

Answer 14

a phospholipid bilayer membrane structure which makes up the plasma membrane around the cells
(heads are on the outside near water, tails face eachother so not in contact with water)
= barrier for water soluble substances

Question 15

what do all lipids contain

Answer 15

contain a variety of elements but all contain hydrocarbons.
C,H,O,

Question 16

how does carbon link to fatty acid

Answer 16

carbon links fatty acid to glycerol
r group denotes a variable hydrocarbon tail

Question 17

lipid test

Answer 17

1. emulsion test
2. add ethanol and shake
3. add water
4. cloudy white emulsion