Lipids

Question 1

In general, are lipids soluble in aqueous solution?

Answer 1

No

Question 2

Why are lipids suitable for energy storage?

Answer 2

They are reduced compounds & have a lot of available energy & their hydrophobic nature

Question 3

What makes lipids suitable for insulation?

Answer 3

High heat capacity, low thermal conductivity, & absorbs shock

Question 4

What allows lipids to act as water repellants for birds & dessert plants?

Answer 4

Their hydrophobic nature

Question 5

Where do lipids insulate electrical impulses?

Answer 5

Lipids are found in the myelin sheaths

Question 6

Where in the cell are lipids found?

Answer 6

Cell membrane

Question 7

What 2 lipids are major components of cell membranes?

Answer 7

Phospholipids & cholesterol

Question 8

What action does vitamin K aid with?

Answer 8

Blood clotting

Question 9

What does coenzyme Q aid with?

Answer 9

ATP synthesis in mitochondria

Question 10

What hormones act locally?

Answer 10

Paracrine hormones

Question 11

What hormones act body-wide?

Answer 11

Steroid hormones

Question 12

What affects the colour of certain organisms?

Answer 12

Pigments

Question 13

Give an example of an antioxidant

Answer 13

Vitamin E

Question 14

What type of bonds are found in lipids

Answer 14

Nonpolar carbon-hydrogen

Question 15

Does the hydrogen atoms in lipids form bonds with water?

Answer 15

No

Question 16

What 2 units make up fats?

Answer 16

Fatty acids & glycerol

Question 17

What structure do fatty acids typically have

Answer 17

Long chained hydrocarbons with a carboxyl group at the end?

Question 18

What feature does the carboxyl group give to fats?

Answer 18

Slight solubility in water

Question 19

What is another name for fats?

Answer 19

Triglycerides

Question 20

What is a saturated fatty acid?

Answer 20

A fatty acid with no c-c double bonds

Question 21

What is an unsaturated fatty acid?

Answer 21

A fatty acid with at least one c-c double bond

Question 22

What is glycerol?

Answer 22

3 carbon compound with 3 hydroxyl groups

Question 23

Is glycerol water soluble?

Answer 23

Yes

Question 24

What gives glycerol its water solubility?

Answer 24

The polarity of the hydroxyl groups

Question 25

What type of reaction is involved in the formation of a triglyceride?

Answer 25

Condensation dehydration

Question 26

What functional groups are involved in the formation of a triglyceride?

Answer 26

The carboxyl group of 3 fatty acids & the 3 hydroxyl groups of a glycerol molecule

Question 27

What type of fat are animal fats?

Answer 27

Saturated

Question 28

What type of fat are plant fats?

Answer 28

Unsaturated

Question 29

What 2 components make up waxes?

Answer 29

Long chain fatty acid & long chain alcohol

Question 30

What 2 features of waxes make them suitable for protective functions?

Answer 30

Insolubility & high melting point

Question 31

What are waxes function in plankton?

Answer 31

Metabolic fuel

Question 32

What are waxes function in vertebrates?

Answer 32

Protection & pliability of hair & skeleton

Question 33

What are waxes function in plants?

Answer 33

Waxy cuticles prevent water loss

Question 34

What are waxes function in the economy?

Answer 34

Lotions & polishes

Question 35

What makes up a phospholipid?

Answer 35

Glycerol, 2 fatty acids & at least 1 phosphate group

Question 36

Are fatty acids hydrophobic or hydrophilic?

Answer 36

Hydrophobic

Question 37

Are phosphate groups hydrophobic or hydrophilic?

Answer 37

Hydrophilic

Question 38

What happens to phospholipids in aqueous solution?

Answer 38

They self arrange into a phospholipid bilayer

Question 39

What do properties of the phosphate group determine in phospholipids?

Answer 39

The surface properties of the cell membrane

Question 40

What do all steroids have?

Answer 40

A backbone of 4 fused carbon rings

Question 41

What differs between different steroids?

Answer 41

The functional groups attached to the rings

Question 42

What are 2 roles of cholesterol?

Answer 42

Component of cell membrane & precursor to other hormones e.g. sex hormones

Question 43

What is the difference between testosterone & oestrogen?

Answer 43

Testosterone has a carbonyl group attached to it whilst oestrogen has a hydroxyl group attached to it