Lipids

Question 1

What is a lipid?

Answer 1

A carbon-containing compound found in organisms
Largely nonpolar and hydrophobic

Question 2

Do lipids dissolve in water?

Answer 2

Lipids do not dissolve easity in water

Question 3

Lipids are hydrocarbons- What does this mean?

Answer 3

They only contain hydrogen and carbon

Question 4

Lipids are nonpolar molecules which means their ends are …?

Answer 4

Not charged

Question 5

Why are lipids not soluble in water?

Answer 5

They are nonpolar and water is polar meaning that they do not share or bond electrons

Question 6

Fatty acids are the tails of lipids. What is a fatty acid?

Answer 6

Long hydrocarbon chains that end with a carboxyl (-COOH) group

Question 7

What is the general formula?

Answer 7

H3C-(CH)n-COOH

Question 8

What do unsaturated fatty acids contain?

Answer 8

One or more double bond

Question 9

Do unsaturated fatty acids have a high or low melting point?

Answer 9

Low melting point

Question 10

What state is staurated fatty acids of less than 10 carbons at in room temperature?

Answer 10

Liquid

Question 11

Are sturated fatty acids are liquid at room temperature?

Answer 11

Yes

Question 12

What does cis mean?

Answer 12

The hydrogens either side of the double bond may be on the same side

Question 13

What dies trans mean?

Answer 13

The hydrogens either side of the double bond may be on the opposite side of the double bond

Question 14

Do the most naturally occuring unsaturated fatty acid contain cis or trans configuration?

Answer 14

Cis

Question 15

Are trans fats rare?

Answer 15

Yes

Question 16

How are trans fats made?

Answer 16

From cis-unsaturated fats in an industria; process called hydrogentaion

Question 17

What bonds are converted in hydrogenation?

Answer 17

Double bonds are converted into single bonds
Cis bonds are conerted into a trans formation

Question 18

Nucleotides, lipids and carbohydrates are defined by what proterty?

Answer 18

Physical property

Question 19

What are the three most important types of lipids found in cells?

Answer 19

Steroids, phospholipids and fats

Question 20

What is an example of a steroid?

Answer 20

Cholesterol

Question 21

How are steroids distinguished?

Answer 21

Bt the four-ring structure

Question 22

How do steriods differ?

Answer 22

By functional group or side groups attached to these rings

Question 23

Why is cholesterol an important component of plasma membranes?

Answer 23

Provides stability in membranes

Question 24

What are steroids used for?

Answer 24

A starting point for the synthesis of hormones
- Oestrogen
- Progesterone
- Testosterone

Question 25

What does a phospholipid consist of?

Answer 25

Three carbon molecules called glycerol

Question 26

Where are phospholipids containing fatty acid chains found?

Answer 26

In the domains bacteria and eukarya

Question 27

How many fatty acid chains are linked to a single glycerole molecule?

Answer 27

Three

Question 28

What reaction happens for fatty acids and phospholipids to form?

Answer 28

Condensation reaction

Question 29

Where does the condensation reaction occur in fats and phospholipids?

Answer 29

Between the hydroxyl group of glycerol and the carbonyl group of fatty acid

Question 30

How does glycerol and fatty acids become joined?

Answer 30

Ester linkage

Question 31

Are phospholipids and fats polymers?

Answer 31

No

Question 32

Are fatty acids monomers?

Answer 32

No

Question 33

Do membrane lipids have a hydrophobic, polar region?

Answer 33

Yes

Question 34

Does the tails or head of the membrane lipids react when in water solution?

Answer 34

The heads are polar so they are hydrophilic and interact with water The tails are non polar so they are hydrophobic and do not interact with water

Question 35

What is the term for compounds that contain both hydrophilic and hydrophobic elements?

Answer 35

Amphipathis

Question 36

Do phospholipids dissolve when placed in water?

Answer 36

No

Question 37

Do the heads or tails react with the water?

Answer 37

Heads

Question 38

What are the two types of structures that phospholipids spontaniously form when in water?

Answer 38

Micelles and bilayers

Question 39

What does it mean when a structure forms independently?

Answer 39

There is no energy input required

Question 40

How are micelles formed?

Answer 40

When hydrophilic heads face the water and hydrophobic tails are forced together away from the water

Question 41

When are lipid bilayers formed?

Answer 41

When two sheets of lipids align with hydrophilic heads facting the solution and hydrophobic tails facing one another inside the bilayer

Question 42

Are the tails long or short in micelles?

Answer 42

Short

Question 43

Are the tails long or short in lipid bilayers?

Answer 43

Long

Question 44

What happens when the spotaneous formation of lipid bilayers and sealed compartments?

Answer 44

They capture other chemicals within

Question 45

What are fats based ion?

Answer 45

Fatty acids

Question 46

How are fatty acids classified?

Answer 46

the chain length and number of double bonds

Question 47

What does chin length determine?

Answer 47

Melting and boiling points