2.3 Lipids

Question 1

Do lipids dissolve in water? Why?

Answer 1

Lipids do not dissolve in water because they are hydrophobic

Question 2

What is the function of lipids (4)?

Answer 2

-used for long-term energy storage because they store more energy per gram than carbohydrates

-makeup phospholipids and cholesterol in the cell membrane

-makeup chemical signalling molecules such as steroids

-cushioning organs and insulation

Question 3

What are the categories of lipids?

Answer 3

Fats(glycerol), phospholipids, steroids, waxes

Question 4

What is the most common energy storing molecule in living organisms?

Answer 4

Fats

Question 5

How do animals store fats?

Answer 5

Animals convert excess carbohydrates into fats which is stored as droplets in the adipose tissue

Question 6

What is the most common fat?

Answer 6

Triglyceride

Question 7

How is an ester linkage formed?

Answer 7

When glycerol reacts with a fatty acid a condensation reaction occurs between the hydroxyl on a glycerol and the carboxylic group on a fatty forming an ester linkage

Question 8

What is the structure of fatty acids

Answer 8

A carboxyl group on one end followed by a hydrocarbon chain that is 16 to 18 carbons long

Question 9

What are the different types of fatty acids?

Answer 9

-Saturated: contains maximum number of hydrogen bonds

-Unsaturated: contains less than maximum number of hydrogen bonds

-Polyunsaturated: hydrocarbon containing many double bonds

Question 10

What is involved in fat formation?

Answer 10

Glycerol

-one, two, or three, fatty acids

Question 11

What is the structure of phospholipids?

Answer 11

A glycerol connected to two fatty acids, and a phosphate group

The phosphate group is the polar head which makes it hydrophilic

The fatty acids are the non polar tails that are hydrophobic

Question 12

what does the amphipathic nature of phospholipids allow it to do?

Answer 12

The amphipathic nature of the phospholipid molecule allows it to form a variety of cellular structures. These structures can be manipulated for biotechnological purposes or medical applications

Question 13

what do steroids function as?

Answer 13

they function as hormones in various locations of the body

Question 14

what is the structure of steroids?

Answer 14

four fused hydrocarbon rings and several different functional groups

Question 15

what are the structure of waxes?

Answer 15

complex molecules containing long-chain fatty acids linked to an alcohol or carbon ring.

Question 16

what is a characteristic of waxes?

Answer 16

hydrophobic molecules with a firm pliable consistency making them ideal as waterproof coatings for plants