Lipids (Unit 1)

Question 1

Lipids

Answer 1

Not polymers, but very large molecules

Question 2

Lipids are composed of?

Answer 2

Carbon, Hydrogen, and Oxygen

Question 3

What is difference between ratio of atoms in carbohydrates and lipids?

Answer 3

Greater proportion of carbon and hydrogen in lipids causing them to be hydrophilic

Question 4

Types of Lipids in Organisms

Answer 4

Triglycerides, Phospholipids, Steroids, Waxes

Question 5

Function of Triglycerides

Answer 5

Energy storage

Question 6

Parts of a triglyceride

Answer 6

Glycerol and 3 fatty acids

Question 7

Fatty acid

Answer 7

Long hydrocarbon chain with carboxylic acid on end

Question 8

How do fatty acids and glycerol join?

Answer 8

Hydroxyls join through condensation reaction to form an ester link

Question 9

Fat

Answer 9

Saturated fatty acid (single bonds) in straight chains. Found in animals

Question 10

Oils

Answer 10

Unsaturated fatty acid (at least one double bond) in bent chains. Found in plants. Are more flexible

Question 11

Are saturated or unsaturated better?

Answer 11

Unsaturated is healthier, as they are more flexible

Question 12

Hydrogenation

Answer 12

Food preservation that adds hydrogen to unsaturated fatty acid to make it saturated. Causes natural cis-fatty acid to become trans-fatty acids

Question 13

Where are phospholipids found?

Answer 13

Cell membranes

Question 14

How are phospholipids similar to triglycerides?

Answer 14

The same, except one fatty acid is replaced with a phosphate group

Question 15

Are phospholipids hydrophilic or hydrophobic?

Answer 15

Negative charge on phosphate makes head of phospholipid hydrophilic, and long chain makes tails hydrophobic, so molecule is amphipathic. Heads go on outside, hydrophobic tails go on inside of membrane

Question 16

Steroids

Answer 16

Group of lipids containing four fused carbon rings. Differ with side chains

Question 17

Sterols

Answer 17

Have polar hydroxyl group at one end and a hydrocarbon chain at other. Are almost completely hydrophobic, except hydroxyl makes one end slightly hydrophilic

Question 18

Cholesterol

Answer 18

In cell membranes of animals cells

Question 19

Phytosterols

Answer 19

In plant cell membranes

Question 20

Sex hormones

Answer 20

Steroid lipids. Control development of sexual traits and sex cells specific to males/females

Question 21

Waxes

Answer 21

Hydrocarbon chains linked to long alcohol or carbon chain. Nonpolar and hydrophobic

Question 22

Wax Uses

Answer 22

Water resistance and protection on various animal and plant parts