B1.1 (Lipids)

Question 1

Properties & Functions

Triglyceride

Answer 1

• soild at r.t.p
• food + synthesis
• butter, ghee, lard

Question 2

Properties & Functions

Wax

Answer 2

• high m.p
• soild at r.t.p
• surface of leaves

Question 3

Properties & Functions

Steroids

Answer 3

• four carbon rings that are fused
• hormone
• lipids

Question 4

What is a Triglyceride made up of

Answer 4

Glycerol + Three fatty acids

Question 5

Saturated

Answer 5

only single bonds

example: stearic acid, eggs

Question 6

Unsaturated

Answer 6

double or tripple bond

example: oleic acid

Question 7

Polyunsaturated

Answer 7

multiple double or triple bonds

example: vegetable oil (linooleic acid)

Question 8

Why unsaturated fats have lower melting points

Answer 8

Due to the double/triple bond the structure of the fatty acid tilts, causing a less regular arrangement between the chains resulting in less IMF and therefore requireing less energy to be broken

Question 9

Cis fats

Answer 9

• Hydrogens are on the same side
• naturally occuring
• oleic acid (olive oil)

Question 10

Trans fats

Answer 10

• Hydrogens are on opposite sides
• artificially produced
• margarine

Question 11

How are trans fats produced

Answer 11

they are lipids made up of hydrogenated polyunsaturated fats
(which are dangerous as they are considered as bad cholesterol)

Question 12

Good Cholesterol (HDL)

Answer 12

• high density
• takes cholesterol away from blood and returns to liver

Question 13

Bad Cholesterol

Answer 13

• low density
• sticks to arteries and collects
• produces plaque and blocks flow

Question 14

Properties of Lipids

Energy Content

Answer 14

more energy per gram than carbohydrates
(37 kJ/g > 17 kJ/g)

Question 15

Properties of Lipids

Insulation

Answer 15

excellent heat insulation

Question 15

Properties of Lipids

Density

Answer 15

less dense than water

Question 16

Properties of Lipids

Solubility

Answer 16

non polar

Question 17

Properties of Lipids

Waterproof

Answer 17

water insolube

Question 18

importance of fats to endotherms

Endotherms are animals that rely on metabolic reactions to generate heat to maintain a constant internal body temperature

Answer 18

It is particularly important to them as it is stored in their adipocytes as liquid droplets

Question 19

Phospholipids

Answer 19

Type of lipid molecule that is the main component in the cell membrane

Question 20

saturated fats at rtp

Answer 20

solid

Question 20

Structures of phsopholipids

Answer 20

Micell or Bilayer

Question 21

Amphipathic

Answer 21

Any molecule that has both hydrophobic and hydrophilic properties

Question 22

Why the phospholipids bilayer is perfect for membrane strcuture

Answer 22

the outer hydrophilic surface can interact with water while the inner hydrophobic surface can allow substanced like steroids to pass through the bilyaer

Question 23

steroid

Answer 23

4 ringed structure lipid

Question 24

unsaturated fats at rtp

Answer 24

liquid

Question 25

characteristics of lipids

Answer 25

buoyant, insulation, energy storage (most KJ per g)

Question 26

Phospholipid bilayer: membranes (Keywords)

Answer 26

• hydrophilic heads outside
• hydrophobic tails inside
  separates internal and external environment
• non polar steroids can pass through and target receptor site