Topic 1 Lipids

Question 1

• Contain carbon, hydrogen, and oxygen atoms (CHO), like carbohydrates
• Have long hydrocarbon tails that make them very hydrophobic

Answer 1

Lipid

Question 2

• Lipid molecule with a glycerol backbone and three fatty acids
• Glycerol and the three fatty acids are connected by ester linkages
• Saturated: no double bonds, straight chains, bad for health
• Unsaturated: double bonds, kinks, good for health

Answer 2

Triacylglycerol (triglyceride)

Question 3

• Three carbons and three hydroxyl groups

Answer 3

Glycerol backbone

Question 4

• Long hydrocarbon tails

Answer 4

Fatty acids

Question 5

• Have no double bonds and as a result pack tightly (solid at room temperature)

Answer 5

Saturated fatty acids

Question 6

• Have double bonds

- Can be divided into monounsaturated fatty acids and polyunsaturated fatty acids

Answer 6

Unsaturated fatty acids

Question 7

• One double bond

Answer 7

Monounsaturated fatty acids

Question 8

• Two or more double bonds

Answer 8

Polyunsaturated fatty acids

Question 9

• Have kinks that cause the hydrocarbon tails to bend

- Do not pack tightly

Answer 9

Cis-unsaturated fatty acids

Question 10

• have straighter hydrocarbon tails

- pack tightly

Answer 10

Trans-unsaturated fatty acids

Question 11

Phospholipids, Cholesterol, and Steroids

Answer 11

Lipid Molecules

Question 12

• lipid molecules that have a glycerol backbone, one phosphate group, and two fatty acid tails
• the phosphate group is polar
• the fatty acids are nonpolar
• amphipathic
• assemble to form lipid bilayers

Answer 12

Phospholipids

Question 13

• lipid molecule that is a component of the cell membranes and is amphipathic
• the most common precursor to steroid hormones
• the starting material for vitamin D and bile acids

Answer 13

Cholesterol

Question 14

• 3 6-membered rings and 1 five-membered ring

Answer 14

Steroids

Question 15

• both hydrophobic and hydrophilic

Answer 15

Amphipathic

Question 16

• lipids that have four hydrocarbon rings

Answer 16

Steroid Hormones

Question 17

Temperature, Cholesterol, Degrees of unsaturation

Answer 17

Factors that influence membrane fluidity

Question 18

• Increasing temperatures increase fluidity while decreasing temperatures decrease it
• Become rigid in cold water
• Become flexible in warm water

Answer 18

Temperature

Question 19

• Holds membrane together at high temperatures and keeps membrane fluid at low temperatures

Answer 19

Cholesterol

Question 20

• Saturated fatty acids pack more tightly that unsaturated fatty acids, which have double bonds that may introduce kinks

Answer 20

Degrees of unsaturation

Question 21

• Allow the transport of lipid molecules in the bloodstream due to an outer coat of phospholipids, cholesterol, and proteins

Answer 21

Lipoproteins

Question 22

1. Low-density lipoproteins (LDLs)

2. High-density lipoproteins (HDLs)

Answer 22

Types of Lipoproteins

Question 23

• Have low protein density
• Work to deliver cholesterol to peripheral tissues
• Sometimes considered “bad cholesterol” which can cause vessel blockage and heart disease

Answer 23

Low-density lipoproteins (LDLs)

Question 24

• Have high protein density
• Take cholesterol away from peripheral tissues
• Considered “good cholesterol” because they deliver cholesterol to the liver to make bile (reduces blood lipid levels)

Answer 24

High-density lipoproteins (HDLs)

Question 25

• Simple lipids with long fatty acid chains connected to monohydroxy alcohol through ester linkages
• Used mainly as protective coatings on skin and exoskeleton

Answer 25

Waxes

Question 26

• Contain a single hydroxyl group

Answer 26

Monohydroxy alcohols

Question 27

• Lipid derivatives containing long fatty acid carbon chains with conjugated double bonds and six-membered rings at each end
• Function mainly as pigments
• Subgroups: carotenes and xanthophylls

Answer 27

Carotenoids

Question 28

• Have a backbone with alipathic (non-aromatic) amino acids

- Serve important functions in the plasma membranes of cells

Answer 28

Sphingolipids

Question 29

• 4 joined pyrrole rings

Answer 29

Porphyrins

Question 30

• Specialized fat cells
• Two types:
  1. White fat cells
  2. Brown fat cells

Answer 30

Adipocytes

Question 31

• composed of triglycerides with a thin layer of cytoplasm

Answer 31

White fat cells

Question 32

• have cytoplasm, lipid droplets, and mitochondria

Answer 32

Brown fat cells

Question 33

• Carbohydrate group instead of phosphate group like phospholipids

Answer 33

Glycolipids

Question 34

• Transport lipids in the blood

- Lipid cores surrounded by phospholipids and apolipoproteins

Answer 34

Lipoproteins