3.3 Lipids

Question 1

Why do lipids not mix with water?

Answer 1

Due to hydrocarbon in them- hydrophobic

Question 2

What are fats made up of?

triglyceride

Answer 2

3 fatty acids bonded with an esther bond to one molecule of glycerol - triglyceride

Question 3

Glycerol

Answer 3

alcohol (3 carbons, 5 hydrogens, 3 hydroxyl groups)

Question 4

Fatty Acids

Answer 4

a long chain of hydrocarbon tails- hydroxyl group

Question 5

saturated fatty acids

Answer 5

maximum # of hydrogen atoms bonded to carbon; single bonds- solid

Question 6

unsaturated fatty acids

Answer 6

double bonds & oils

Question 7

5 functions of lipids

Answer 7

1. long term energy as fats
2. insulation for plants & animals
3. keeps aquatic birds & mammals dry
4. building blocks for homores
5. constituent of cell membrane

Question 8

Atherosclerosis

Answer 8

plaques in blood vessels; impede blood flow & reduces resilience of vessel

Question 9

trans fat

Answer 9

oils are hydrogenated- semi solid & good consistency
trans double bonds
increase (LDL)- bad cholesterol- heart disease
hydrogens are on opposite sides- no kink

Question 10

What do unsaturated and saturated fats cause?

Answer 10

Unsaturated fats- decrease blood cholesterol levels
Saturated fats- plaque formation in arteries

Question 11

Adipocytes

Answer 11

a place where mammals store fats; where globules of fat occupy most of the cell (specialized cell)

Question 12

What are phospholipids made out of?

Answer 12

2 fatty acids; glycerol and phosphate grou

Question 13

amphiphatic

Answer 13

hydrophobic (fatty acids) and hydrophilic (phosphate group & glycerol)

Question 14

Micelle

Answer 14

cell membrane structure; hydrophobic phosphathe heads face outside and fatty acids face inside

Question 15

Steroids structure

Answer 15

4 linked carbon rings & has a short tail
OH functional group

Question 16

Cholesterol function

Answer 16

synthesized in the liver & precursor to steroid hormones
(testosterone & estradial- secreted by gonads and endocrine glands)
precursor to vitamin d and bile salts- emulsification of fats & absorption by cells

Question 17

What does cholesterol do in the cell membrane?

Answer 17

separate the phospholipids and keep them together

Question 18

Function of the plasma membrane

Answer 18

the transport of materials and cellular recognition and it is involved in cell-to-cell communication.

Question 19

Cis Fatty Acids structure

Answer 19

has both hydrogen atoms on the same side

Question 20

Trans fatty acids structure

Answer 20

has both hydrogen atoms on the opposite side

Question 21

What is the effect of double bonds to membrane fluidity?

Answer 21

decreases fluidity

Question 22

Function of choline in phospholipids?

Answer 22

It can be substituted for other atoms

Question 23

What are micelles?

Answer 23

the ways phospholipids are arranged in a bilayer in the cell membrane or spheres

Question 24

What do waxes do?

Answer 24

Coat the surface of leaves to prevent water loss