Chapter 11: Lipids

Question 1

What are lipids soluble in?

Answer 1

Organic solvents

Question 2

What are the five classes of lipids?

Answer 2

• Free fatty acids
• Triacylglycerols
• Phospholipids
• Glycolipids
• Steroids

Question 3

A common fuel

Answer 3

Free fatty acids

Question 4

Storage form of fatty acids

Answer 4

Triacylglycerols

Question 5

Membrane lipids

Answer 5

Phospholipids

Question 6

Membrane lipids composed in part of carbohydrates

Answer 6

Glycolipods

Question 7

Polycyclic hydrocarbons with a variety of functions

Answer 7

Steroids

Question 8

Fatty acids are chains of hydrogen-bearing side chains that have ___________ _______ at one end and a _________ _________ at the other end.

Answer 8

Carboxylic acid, methyl group

Question 9

True or False:
Fatty acids may be saturated or unsaturated

Answer 9

True

Question 10

Fatty acid carbon atoms are usually numbered beginning
with the?

Answer 10

Carboxyl terminal carbon atom.

Question 11

Carbon atom 2 is _ and 3 is _.

Answer 11

α, β

Question 12

Fatty acids can also be numbered from the methyl
carbon atom, which is called the

Answer 12

Omega (ω) carbon.

Question 13

The positions of double bonds are indicated with the
symbol Δ, with the _____ atom of the double bond indicated
by a superscript number.

Answer 13

First

Question 14

Because fatty acids are ionized at physiological pH, they are usually referred to as their ___________- form

Answer 14

Carboxylate

Question 15

True or False:
Fatty acids usually have a even number of carbon atoms.

Answer 15

True

Question 16

When double bonds are present they are commonly in the ___ configuration

Answer 16

Cis

Question 17

In polyunsaturated fatty acids, the double bonds are
separated by at least one what?

Answer 17

Methylene group

Question 18

Properties of fatty acids are dependent on what?

Answer 18

Chain length and degree of unsaturation

Question 19

Longer chains = higher or lower melting point?

Answer 19

Higher

Question 20

If a chain is more saturated it has a higher or lower melting point?

Answer 20

Higher

Question 21

If a chain has more double bonds it has a higher or lower melting point?

Answer 21

Lower

Question 22

Cis double bonds increase or decrease melting point?

Answer 22

Decrease

Question 23

Trans double bonds increase or decrease melting point?

Answer 23

Increase

Question 24

Cis polyunsaturated fatty acids are essential components of our
diets because why?

Answer 24

Humans cannot synthesize them

Question 25

Fatty acids are stored as what?

Answer 25

Triacylcerols

Question 26

How does the composition of triacylglycerols come about?

Answer 26

Three fatty acids are esterified to one molecule of glycerol.

Question 27

What are soaps?

Answer 27

The sodium or potassium salts of fatty acids

Question 28

How do soaps work?

Answer 28

Treating triacylglycerols with a strong base

Question 29

What is the major site for triacylglycerol storage in mammals?

Answer 29

Adipose tissue

Question 30

Triacylglycerols can store much more energy because they are what?

Answer 30

Hydrophobic and reduced

Question 31

Three common types of membrane lipids

Answer 31

Phospholipids Glycolipids Cholesterol

Question 32

Phospholipids are composed of four components:

Answer 32

Fatty acids (2 or more), a platform, a phosphate, and an alcohol

Question 33

Two common platforms for phospholipids are what?

Answer 33

Glycerol and sphingosine

Question 34

Phospholipids with a glycerol platform are called what?

Answer 34

Phosphoglycerols

Question 35

The major phospholipids are derived from what?

Answer 35

Phosphatidate

Question 36

Phospholipids built on a sphingosine platform are called:

Answer 36

Sphingolipids.

Question 37

Sphingomyelin is common where?

Answer 37

Myelin sheath of nerve cells

Question 38

What are carbohydrate-containing lipids?

Answer 38

Glycolipids

Question 39

The carbohydrate components of glycolipids are on the __________________ surface of the cell membrane.

Answer 39

Extracellular

Question 40

Simplest glycolipids

Answer 40

Cerebrosides

Question 41

Steroids are built on a ______________ platform

Answer 41

Tetracyclic

Question 42

Steroids are made up of what?

Answer 42

Three cyclohexane rings and a cyclopentane ring fused together

Question 43

What is the most common steroid?

Answer 43

Cholesterol

Question 44

What is steroids role?

Answer 44

Maintaining membrane fluidity

Question 45

Play the role of cholesterol in prokaryotes and plants

Answer 45

Hopanoids

Question 46

The ether linkages and branching structure of membrane lipids of _______________ prevent hydrolysis and oxidation of membranes in harsh environments

Answer 46

Extremophiles

Question 47

Membrane lipids are ______________ meaning they have hydrophilic and hydrophobic properties

Answer 47

Amphipathic

Question 48

Alcohol and phosphate components provide the _________________ properties

Answer 48

Hydrophilic

Question 49

The fatty acid components provide the

Answer 49

Hydrophobic properties

Question 50

Localize the protein to the cell membrane occurs by

Answer 50

Proteins covalently bound to lipids