Module 8 - 1

Question 1

What are lipids?

Answer 1

A diverse family of compounds that share the defining feature of insolubility in water.

Question 2

What are the functional characteristics of lipids?

Answer 2

Energy storage, structural component of membranes, signalling, enzyme co-factors & vitamins.

Question 3

What are fatty acids?

Answer 3

Hydrocarbon derivatives with a carboxylic head.

Question 4

What are the different types of double bonds within fatty acids?

Answer 4

Saturated (no double bonds), unsaturated (1 double bond), polyunsaturated (multiple double bonds).

Question 5

What is the nomenclature of fatty acids based on?

Answer 5

Length, presence or absence of double bonds, location of double bonds.

Question 6

What is the structure of fatty acids?

Answer 6

Hydrocarbon tails associate through hydrophobic and Vander Waals interactions.

Question 7

What is the association of fatty acids based on?

Answer 7

Melting temperature, length and degree of saturation of hydrocarbon tails, and double bonds.

Question 8

What are lipids?

Answer 8

Critical energy storage molecules for plants and animals.

Question 9

Where do lipids occupy most of the intracellular space?

Answer 9

Adipocytes.

Answer 10

Insulating function for cold weather animals.

Question 11

What are triacylglycerols?

Answer 11

Fatty acid esters of glycerol.

Question 12

What are the characteristics of simple triacylglycerols?

Answer 12

Same three fatty acids at each position.

Question 13

What are the characteristics of complex triacylglycerols?

Answer 13

Different fatty acids.

Question 14

What is the function of the ester linkage?

Answer 14

To remove the polar carboxyl group to make a more hydrophobic molecule.

Question 15

What are the different biological roles of energy storage molecules?

Answer 15

Different energy storage molecules serve different biological roles.

Answer 16

Fats.

Question 17

How much more energy is in fats than carbohydrates on a gram per gram basis?

Answer 17

Six times.

Question 18

What are the characteristics of lipids that make them effective as long-term energy storage molecules?

Answer 18

Low oxidation state and low hydration state.

Question 19

What is saponification?

Answer 19

The process of breaking ester linkages to release free fatty acids.

Question 20

What are the amphipathic properties of free fatty acids?

Answer 20

Effective in solubilization of hydrophobic substances.

Question 21

What is the function of fatty acids as detergents and soaps?

Answer 21

Formation of micelles that capture hydrophobic molecules.

Question 22

What is the process of making soap from fat called?

Answer 22

Saponification.

Question 23

What is the function of micelles?

Answer 23

To capture hydrophobic molecules.

Question 24

What is the function of lipids in adipocytes?

Answer 24

Energy storage.

Question 25

What is the function of fat storage under the skin?

Answer 25

Insulation for cold weather animals.

Question 26

What is the function of triacylglycerols?

Answer 26

Storage lipids in animals and plants.

Question 27

What is Olestra?

Answer 27

A molecule that looks and tastes like fat, but cannot be processed by our digestive system.

Question 28

What is Olestra made of?

Answer 28

Eight fatty acids linked to a sugar group.

Question 29

What are the properties of Olestra?

Answer 29

It looks and tastes like fat but passes through the digestive system without being absorbed.

Question 30

What are the side effects of Olestra?

Answer 30

There are some side effects.

Question 31

What are waxes?

Answer 31

Non-polar esters of long-chain fatty acids and long chain mono hydroxylic alcohols.

Question 32

What are the properties of waxes?

Answer 32

Very water insoluble and have high melting temps (60-100 C).

Question 33

Where are waxes found?

Answer 33

Widely distributed in nature as protective waterproof coatings on leaves, fruits, animal skin, and feathers.

Question 34

What do membrane bilayers do?

Answer 34

Define cells and regulate the composition of the intracellular environment.

Question 35

What is the consequence of the properties of the molecules that compose membranes?

Answer 35

Formation of membranes is a spontaneous consequence.

Question 36

What are the properties of the lipid components of membranes?

Answer 36

They tend to have similar overall shapes and properties, with two hydrophobic tails and a hydrophilic head group.

Question 37

How can membrane lipids be classified?

Answer 37

Based on their backbone (glycerol vs sphingosine) or by their polar head groups (phospho vs glyco).

Question 38

What are glycerophospholipids?

Answer 38

The most abundant lipids in membranes, with a glycerol backbone and a phosphate at the C3 position (Glycerol 3-phosphate).

Question 39

What is phosphatidate?

Answer 39

Glycerol-3-Phosphate + 2 fatty acids.

Question 40

What is the point of attachment for a variety of polar head groups in glycerophospholipids?

Answer 40

The phosphate group.

Question 41

What are the different polar head groups for glycerophospholipids?

Answer 41

They can carry positive, negative, or neutral charge.

Question 42

What is the likely association between different head groups and specialized functions?

Answer 42

Phosphatidylinositol is involved in intracellular signal transduction.

Question 43

What are galactolipids and sulfolipids?

Answer 43

Structural lipids in membranes.

Question 44

What is the role of sugar and sulfate polar head groups in plants?

Answer 44

To conserve use of phosphate for more critical applications.

Question 45

What are galactolipids?

Answer 45

One or two galactose groups linked to C3 of diacylglycerol.

Question 46

What are sulfolipids?

Answer 46

Lipids found in plants.

Question 47

What are sphingolipids?

Answer 47

Lipids derived from sphingosine.

Question 48

What is the structure of ceramide?

Answer 48

Structurally similar to diacylglycerol.

Question 49

What are some common sphingolipids?

Answer 49

Sphingomyelins, cerebrosides, and gangliosides.

Question 50

What determines blood type?

Answer 50

Glycosphingolipids.

Question 51

How are cells recognized as 'self' vs 'non-self'?

Answer 51

Based on patterns of surface exposed carbohydrates.

Question 52

What are some unique membrane lipids found in extremophiles?

Answer 52

Ethers linkages, branch points within the hydrocarbon tails, and membrane spanning hydrocarbon tails composed from a single molecule.