Lipids

Question 1

What are lipids insoluble in

Answer 1

Water

Question 2

What are lipids soluble in

Answer 2

Organic solvent

Question 3

What elements do lipids contain

Answer 3

H C and O however may contain others

Question 4

What are fatty acids

Answer 4

A long hydrocarbon chain with a carboxyl group at the end

Question 5

How many types of fatty acids are there

Answer 5

70 types

Question 6

What is the general formula for fatty acids

Answer 6

CnH2nO2

Question 7

What are triglycerides

Answer 7

Natural fats and oils

Question 8

What do triglycerides consist of

Answer 8

A glycerol molecule and 3 fatty acids

Question 9

What reaction forms a triglyceride

Answer 9

A condensation reaction

Question 10

Why are lipids useful for organisms

Answer 10

Excellent energy store for animals

low mass : energy so a large amount of energy in a small volume

Large and nonpolar- soluble in water with no effect on Water potential

Question 11

What bond joins fatty acids to glycerol

Answer 11

Ester bond

Question 12

What are the types of fatty acids

Answer 12

saturated and unsaturated

Question 13

What does a saturated fatty acid mean

Answer 13

No double bond between carbon atoms in the hydrocarbon chain

Question 14

What does a unsaturated fatty acid mean

Answer 14

More than one double bond between carbon atoms in the hydrocarbon chain

Molecule is able to bend

Question 15

What does a phospholipid consist of

Answer 15

a glycerol molecule joined to two fatty acids and a phosphate molecule

Question 16

What are some uses for phospholipids

Answer 16

Polar so when they are in aqueous environment a bilayer can form and they are the main component of cell membranes

Create a hydrophobic core in the phospholipid bilayer

hydrophobic head means the phospholipid can be used to

From glycolipids allowing the CSM to recognise cells

Question 17

What type of head does a phospholipid have

Answer 17

Hydrophylic head

Question 18

What type of tail does a phospholipid have

Answer 18

Hydrophobic tail

Question 19

What is glycerol

Answer 19

An alcohol molecule with a formula C3H8O3

Question 20

How does a phospholipid differ from a triglyceride

Answer 20

A phospholipid has a phosphate group and 2 fatty acids

A triglyceride has 3 fatty acids

Question 21

How would you test for a lipid

Answer 21

Add ethanol to food molecules, shake then add water

If a white milky substance is shown, lipids are present if its colourless they are not

Question 22

What result shows a positive ethanol test

Answer 22

White milky water

Question 23

What are the two types of unsaturated tryglycerides

Answer 23

Monosaturated-1 double bond between carbon molecules

Polysaturated-many double bonds between carbon molecules

Question 24

What type of reaction forms an ester bond

Answer 24

Condensation reaction

Question 25

What are the functions of triglycerides

Answer 25

Energy storage- when TGs are oxidised bonds break releasing energy used to produce ATP Insulation - part of the myelin sheath which surround nerve fibres which increases speed of nerve impulse transmission Buoyancy- low density of fat tissue allows the ability for animals to float more easily Protection- helps protect organs in mammals from the risk of damage due to the adipose tissue in mammals

Question 26

Name the group represented by COOH

Answer 26

Carboxyl

Question 27

Describe the formation of triglycerides

Answer 27

One glycerol and 3 fatty acids joined by an ester bond in a condensation reaction by removing 3 water molecules

Question 28

Describe how an ester bond is formed in a phospholipid molecule

Answer 28

In a condensation reaction due to a loss of water. The bond is formed between the glycerol and fatty acid