Lipids

Question 1

What are the 3 main types of lipids?

Answer 1

-Triglycerides-Phospholipids-Cholesterol

Question 2

What elements are lipids made from?

Answer 2

C, H and O

Question 3

What are triglycerides compromised of?

Answer 3

One glycerol and three fatty acids each attached by an ester bond.

Question 4

What is an ester bond?

Answer 4

A product of joining of an alcohol and carboxylic acid.

Question 5

How is each easter bond formed?

Answer 5

By a condensation reaction called esterification.

Question 6

What are triglycerides used for?

Answer 6

-Energy Store/Respiration-Insulation (thermal and electrical)-Protection of organs-Buoyancy and Waterproof feathers.

Question 7

All fatty acids have the same basic structure but what changes about them?

Answer 7

Have a variable R group which consist of a hydrocarbon tails.

Question 8

Why are triglycerides a good energy?

Answer 8

The hydrocarbon chains contain a lot of energy.

Question 9

Where are triglycerides stored and what do they form there?

Answer 9

Stored in adipocytes (in adipose tissue) where they form insoluble droplets. (so doesn’t affect water potential)

Question 10

To be broken down, how many water molecules need to be supplied to reverse the reaction that formed the triglyceride?

Answer 10

3

Question 11

What are Saturated Fats?

Answer 11

Fatty Acid Chains with no double bonds present between the carbon chains.

Question 12

All the carbon atoms form how many bonds with the hydrogen atoms?

Answer 12

Form the maximum number of bonds.

Question 13

What are the main properties of saturated fats?

Answer 13

-no kinks-high density-solids at room temperature

Question 14

What are unsaturated fats?

Answer 14

Fatty Acid with double bonds between some of the carbon atoms.

Question 15

What are the 2 types of unsaturated fats?

Answer 15

Monounsaturated Polyunsaturated

Question 16

How many double bonds do monounsaturated fats have?

Answer 16

1

Question 17

How many double bonds do polyunsaturated fats have?

Answer 17

2 or more

Question 18

What are the main properties of unsaturated fats?

Answer 18

-no kinks-high density-liquid at room temperature

Question 19

What are the main properties of polyunsaturated fats?

Answer 19

-lots of kinks-low density-liquid at room temperature-Many C=C

Question 20

What causes the molecules to kink or bend?

Answer 20

The presence of double bonds.

Question 21

Why aren’t the molecules able to pack so closely together?

Answer 21

Due to the double bonds.

Question 22

Plants contain what type of triglycerides?

Answer 22

Unsaturated

Question 23

What do these triglycerides normally occur as?

Answer 23

Oils

Question 24

What are they more healthy than in the human diet?

Answer 24

Saturated triglycerides or (solid) fats.

Question 25

What does the evidence suggest about saturated fats?

Answer 25

Can lead to coronary heart disease.

Question 26

What is the process to test for lipids?

Answer 26

1)Take sample of either oil or water.2)Add 2cm3 of ethanol3)Shake4)Add around 2cm3 of distilled water5)A white emulsion indicates a lipid present.

Question 27

What does a cis double bond look like?

Answer 27

Double Carbon bond with both hydrogen below and R and R’ on top.

Question 28

What does a trans double bond look like?

Answer 28

Double Carbon Bond with Hydrogen on diagonal and R and R’ on diagonal.

Question 29

Which ones are the most naturally formed fats?

Answer 29

Cis

Question 30

How are trans fats made?

Answer 30

Adding Hydrogen to form unsaturated fats.

Question 31

What are phospholipids?

Answer 31

Similar to triglycerides except one of the fatty acid molecules is replaced with a hydrophilic phosphate group.

Question 32

What is the role of phospholipids?

Answer 32

Make up the phospholipids bilayer(cell membrane) of all eukaryotic and prokaryotic cells.

Question 33

How many regions does cholesterol have?

Answer 33

3

Question 34

What are these 3 regions of cholesterol?

Answer 34

-Hydrophobic hydrocarbon tail-Hydrophobic hydrocarbon ring structure-Hydrophilic hydroxyl group

Question 35

In eukaryotic cells, where does cholesterol bind to?

Answer 35

The hydrophobic tails of the phospholipids.

Question 36

What does this binding help the cell do?

Answer 36

Compresses the phospholipids which helps to strengthen and support the membrane.

Question 37

What is cholesterol also used for?

Answer 37

Make steroid hormones, bile and vitamin D (when exposed to light).