2.2 Lipids

Question 1

what are solid lipids at room temperature called?

Answer 1

fats

Question 2

what are liquid lipids at room temperature called?

Answer 2

oil

Question 3

what are the functions of lipids?

Answer 3

• energy storage
• energy source
• cell membranes
• insulation

Question 4

what elements are lipids make of?

Answer 4

carbon, hydrogen + oxygen

Question 5

what is a property of all lipids?

Answer 5

insoluble in water

Question 6

What are the structural components of triglycerides?

Answer 6

glycerol + 3 fatty acids

Question 7

what is the bond formed between the fatty acids and glycerol in triglycerides?

Answer 7

ester bond

Question 8

why are triglycerides not considered polymers?

Answer 8

not made up of repeating sub-units

Question 9

what are the structural components of fatty acids?

Answer 9

carboxylic group + hydrocarbon tail

Question 10

what is the formula for a carboxylic group?

Answer 10

COOH

Question 11

What is the difference in structure between unsaturated vs. saturated fatty acids?

Answer 11

unsaturated = double carbon bonds
saturated = single carbon bonds

Question 12

What state is unsaturated fat in at room temperature?

Answer 12

liquid

Question 13

why is unsaturated fat liquid at room temp.?

Answer 13

low melting point

Question 14

What state is saturated fat in at room temperature?

Answer 14

solid

Question 15

why is saturated fat solid at room temp.?

Answer 15

high melting point

Question 16

In what ways can fatty acids of triglycerides differ in structurally?

Answer 16

saturated or unsaturated
mono-unsaturated vs. poly-unsaturated
cis or trans

Question 17

what is the structural difference between between mono-unsaturated vs. poly-unsaturated fatty acids in triglycerides?

Answer 17

mono-unsaturated: single double carbon bond.
poly-unstaurated: many double carbon bonds.

Question 18

what is the structural difference between cis and trans fatty acids?

Answer 18

cis = hydrogen atoms attached to the same side of the carbon double bond
trans = hydrogen atoms attached to opposite sides of the carbon doubke bond.

Question 19

which one of the cis or trans isomer promotes good cholesterol?

Answer 19

cis

Question 20

What is another name for bad cholesterol known as?

Answer 20

low density lipoproteins

Question 21

How else is good cholesterol known as?

Answer 21

high density lipoproteins

Question 22

why are low density lipoproteins bad for you?

Answer 22

sticks to walls of arteries + block blood flow

Question 23

why are high density lipoproteins good for you?

Answer 23

takes cholesterol away from the blood and return it to the liver.

Question 24

what are the structural components of phospholipids?

Answer 24

glycerol, phosphate +2 fatty acids

Question 25

what is a property of phospholipids?

Answer 25

amphipathic

Question 26

what does amphipathic mean?

Answer 26

having both hydrophilic and hydrophobic regions

Question 27

what are steroids?

Answer 27

a group of naturally occurring hormones

Question 28

what is the chemical structure of cholesterol?

Answer 28

composed of 4 carbon based rings

Question 29

why are cholesterols an important component of the phospholipid bilayer?

Answer 29

provides stability + flexibility

Question 30

what is a property of steroids?

Answer 30

hydrophobic

Question 31

why is it useful that steroids are hydrophobic?

Answer 31

can pass through the lipid bilayer more easily so effects are immediate

Question 32

what is the main role of triglycerides?

Answer 32

energy storage

Question 33

why is it important that triglycerides are insoluble?

Answer 33

so it does not affect water potential

Question 34

what is the main role of phospholipids?

Answer 34

make up membranes

Question 35

What is the most common type of fat?

Answer 35

triglycerides