Chapter 2: Lipids

Question 1

What categories are included in lipids?

Answer 1

• fats, complex lipids (ex. phospholipids), and steroids

Question 2

What is the function of lipids? (2)

Answer 2

1. Essential to the structure and function of membranes
2. used for energy storage

Question 3

What is the polarity of lipids?

Answer 3

• non-polar
• hydrophobic

Question 4

What components make up fats? (2)

Answer 4

• glycerol backbone
• one or more fatty acids

Question 5

How many fatty acids does a:
1) monoacylglycerides
2) diacylglycerides
3)triacylglycerides
have?

Answer 5

1,2,3 FA respectively

Question 6

Fatty acids can be saturated or unsaturated. What does this mean?

Answer 6

saturated - no double bonds
unsaturated - double bonds

Question 7

What components make up phospholipids? (3)

Answer 7

• glycerol
• 2 FA
• a phosphate group

Question 8

Is the phosphate group in phospholipids polar or non-polar? hydrophobic or hydrophilic?

Answer 8

• polar
• hydrophilic

Question 9

Are the fatty acid tails in phospholipids polar or non-polar? hydrophilic or hydrophobic?

Answer 9

• non- polar
• hydrophobic

Question 10

What does the structure of phospholipids allow for it to do in water?

Answer 10

• allows them to form membranes in water

Question 11

What kind of structural patterns form when the fatty acids in phospholipids are saturated?

Answer 11

• saturated FA tend to form membranes that are more solid

Question 12

What kind of structural patterns form when the fatty acids in phospholipids are unsaturated?

Answer 12

• FA that are unsaturated form more fluid membranes

Question 13

What are biological membranes made of?

Answer 13

• made from a phospholipid bilayer

Question 14

What is the structure of biological membranes?

Answer 14

• semi-fluid because they contain a mix of saturated and unsaturated FA

Question 15

What is the function of biological membranes?

Answer 15

• separate the watery inside of the cell from the watery environment

Question 16

What is the structure of steroids (or sterols)?

Answer 16

• structurally different from other lipids
• built on a hydrophobic 4 ring structure

Question 17

Which organisms are steroids usually found in, and give examples of steroids.

Answer 17

• generally found in eukaryotes (not prokaryotes)
• cholesterol, ergosterol, and vitamin D