Module 2 Chapter 2 Lesson 5 - Lipids

Question 1

Where are lipids stored?

Answer 1

Adipose tissue

Question 2

What is the most common type of lipids?

Answer 2

Triglycerides

Question 3

What are triglycerides made out of?

Answer 3

3 molecules of fatty acids bonded to 1 glycerol molecule.

Question 4

What happens to excess triglycerides in the body?

Answer 4

Released for energy.

Question 5

What is the maximum healthy concentration of triglycerides in the body?

Answer 5

<150 mg/dl

Question 6

What diseases can occur with increased level of triglycerides?

Answer 6

Heart Disease
Stroke
Atherosclerosis

Question 7

Describe the structure of a fatty acid.

Answer 7

Central carbon
One side is attached to hydroxyl group
Other is attached to an R group.
C=O Double bond

Question 8

What is the R group on a fatty acid?

Answer 8

A hydrocarbon chain.

Question 9

What are the two things that may change in an R group on a fatty acid?

Answer 9

Length
Double or single bonds

Question 10

What is the bond formed when a glycerol bonds to a fatty acid?

Answer 10

Ester bond

Question 11

What is the name of the process when a glycerol bonds to a fatty acid?

Answer 11

Esterification

Question 12

What is the type of reaction when a glycerol bonds to a fatty acid?

Answer 12

Condensation

Question 13

What are saturated fatty acids in?

Answer 13

Animal fat

Question 14

Do saturated fatty acids have C=C double bond?

Answer 14

No

Question 15

Do unsaturated fatty acids have C=C double bond?

Answer 15

Yes

Question 16

What state are unsaturated fatty acids in at room temperature?

Answer 16

Liquid

Question 17

What are unsaturated fatty acids in?

Answer 17

Plants - olive oil etc

Question 18

What is higher in saturated fatty acids than in unsaturated fatty acids?

Answer 18

The hydrogen to carbon ratio

Question 19

Why do unsaturated fats bend/kink?

Answer 19

They have a double bond between the hydrogen and the carbon.

Question 20

Why are unsaturated fatty acids liquid at room temperature?

Answer 20

Because they have bends/kinks in them.

Question 21

In solid products why are unsaturated fatty acids not healthy?

Answer 21

They are hydrogenised.

Question 22

What are four uses of triglycerides?

Answer 22

Energy Storage
Insulation
Buoyancy
Protection

Question 23

What is hydrophilic?

Answer 23

Attracted to water.

Question 24

What is hydrophobic?

Answer 24

Repels water

Question 25

What is a use of phospholipids?

Answer 25

Pulmonary surfactants in lungs.

Question 26

What is a feature of phospholipids that make them useful?

Answer 26

Head is hydrophilic Tail is hydrophobic

Question 27

What do triglycerides primarily consist of?

Answer 27

Long hydrocarbon chains with many carbon-hydrogen bonds and little oxygen

Question 28

What happens to triglycerides during cellular respiration?

Answer 28

They are oxidised, causing the carbon-hydrogen bonds to break and releasing energy

Question 29

What is the energy released f rom oxidising triglycerides used for?

Answer 29

To produce ATP

Question 30

Fill in the blank: Triglycerides are highly _______.

Answer 30

reduced

Question 31

True or False: Triglycerides contain a high amount of oxygen relative to carbon-hydrogen bonds.

Answer 31

False

Question 32

What are triglycerides a part of in the nervous system?

Answer 32

The composition of the myelin sheath that surrounds nerve fibres

Question 33

What is the function of the myelin sheath?

Answer 33

Provides insulation which increases the speed of transmission of nerve impulses

Question 34

What role do triglycerides play in the adipose tissue layer below the skin?

Answer 34

Acts as insulation against heat loss

Question 35

Fill in the blank: The _______ of whales is an example of insulation against heat loss.

Answer 35

blubber

Question 36

How does the low density of fat tissue affect animals?

Answer 36

Increases the ability of animals to float more easily

Question 37

What is one protective function of adipose tissue in mammals?

Answer 37

Helps protect organs from the risk of damage

Question 38

What is the structure of a phospholipid bilayer?

Answer 38

Composed of two layers of phospholipid molecules with hydrophobic tails facing each other and hydrophilic heads facing outward.

Question 39

What do the hydrophobic tails of phospholipids form?

Answer 39

A hydrophobic interior.

Question 40

What do the hydrophilic heads of phospholipids interact with?

Answer 40

The surrounding water-based environment.

Question 41

How does the phospholipid bilayer function in cell membranes?

Answer 41

Acts as a semi-permeable barrier, allowing small, hydrophobic molecules to pass through while excluding larger, hydrophilic molecules.

Question 42

What does the phospholipid bilayer help cells regulate?

Answer 42

What enters and exits the cell.

Question 43

What is one key role of the phospholipid bilayer?

Answer 43

Maintaining the integrity and stability of cells.

Question 44

True or False: The phospholipid bilayer allows all molecules to pass through freely.

Answer 44

False.

Question 45

Fill in the blank: The phospholipid bilayer helps maintain the proper balance of _______ and other substances within the cell.

Answer 45

ions

Question 46

Give three similarities between triglycerides and phospholipids.

Answer 46

Both macromolecules Both have hydrocarbon chains Both have ester bonds

Question 47

What is the chemical structure of triglycerides?

Answer 47

Triglycerides consist of one glycerol molecule bonded to three fatty acid chains. ## Footnote Triglycerides are primarily used for energy storage in organisms.

Question 48

What is the chemical structure of phospholipids?

Answer 48

Phospholipids consist of one glycerol molecule bonded to two fatty acid chains and a phosphate group. ## Footnote Phospholipids are crucial for forming cell membranes.

Question 49

What is the primary functionality of triglycerides?

Answer 49

Triglycerides serve as energy storage molecules. ## Footnote They are stored in adipose tissue and can be metabolized for energy.

Question 50

What is the primary functionality of phospholipids?

Answer 50

Phospholipid bilayer in cell surface membrane.

Question 51

Fill in the blank: Triglycerides are entirely _______ and insoluble in water.

Answer 51

nonpolar

Question 52

Fill in the blank: Phospholipids have both _______ and _______ regions.

Answer 52

hydrophilic, hydrophobic ## Footnote This duality allows phospholipids to form bilayers in cell membranes.

Question 53

True or False: Triglycerides can form bilayers in cell membranes.

Answer 53

False ## Footnote Only phospholipids can form bilayers due to their chemical structure.

Question 54

What is cholesterol?

Answer 54

An important lipid molecule found in the cell membrane of eukaryotic cells ## Footnote Cholesterol plays a crucial role in cellular structure and function.

Question 55

What regions do cholesterol molecules have?

Answer 55

Hydrophobic and hydrophilic regions ## Footnote This dual character allows cholesterol to integrate into the cell membrane.

Question 56

Where are cholesterol molecules synthesized?

Answer 56

In the liver ## Footnote Liver cells are responsible for producing cholesterol which is crucial for various bodily functions.

Question 57

How is cholesterol transported in the body?

Answer 57

Via the blood

Question 58

What effect does cholesterol have on the fluidity of the cell membrane?

Answer 58

At high temperatures it reduces fluidity. At low it prevents rigidity.

Question 59

How does cholesterol disrupt the packing of phospholipids?

Answer 59

Increases the rigidity of the membrane ## Footnote This increased rigidity makes the membrane less flexible.

Question 60

What role does cholesterol play in diffusion across the membrane?

Answer 60

It acts as a barrier, preventing water-soluble substances from diffusing across the membrane ## Footnote Cholesterol fits in the spaces between phospholipids.

Question 61

What types of hormones are produced from cholesterol?

Answer 61

Steroid-based hormones such as oestrogen, testosterone, and progesterone ## Footnote Cholesterol is a precursor for these essential hormones.

Question 62

Fill in the blank: Cholesterol molecules have __________ and hydrophilic regions.

Answer 62

hydrophobic ## Footnote This characteristic is important for their function in cell membranes.