ch.5

Question 1

do lipids fit the polymer model like other macromolecules

Answer 1

no, they are not made up of monomers

Question 2

how are lipids

Answer 2

hydrophobic interactions

Question 3

what are neutral molecules in lipids due to

Answer 3

the hydrocarbon chains

Question 4

what are the four types of lipids and their examples

Answer 4

• triglycerides
• fatty acids
• steroids
• phospholipids

Question 5

triglycerides

Answer 5

lard, suet, olive oil, peanut oil, butter (water insoluble)

Question 6

fatty acids

Answer 6

linoleic (omega-6, flaxseed oil), linolenic (omega-3, fish oil)

Question 7

steroids

Answer 7

estrogen, vitamin D, cholesterol (membrane component, hormones)

Question 8

phospholipids

Answer 8

lecithin (amphipathic, membrane component)

Question 9

what are the classes of lipids and their functions

Answer 9

1. neutral fats (energy storage, insulation, cushioning, buoyancy)
2. steroids
3. phospholipids

Question 10

what is the basic structure of a triglyceride

Answer 10

a triglyceride consists of 3 fatty acids attached to one molecule of glycerol

Question 11

what is a fatty acid composed of

Answer 11

a fatty acid is composed of a long hydrocarbon chain with a carboxyl (-COOH) group at the end

Question 12

what is glycerol

Answer 12

3-carbon alcohol containing 3 hydroxyl (-OH) groups

Question 13

how are triglycerides formed

Answer 13

through 3 dehydration reactions involving ester linkages

Question 14

what replaces the third fatty acid in a phospholipid structure

Answer 14

a phosphate group replaces the third fatty acid in a phospholipid structure

Question 15

what characterizes the structure of a steroid

Answer 15

skeleton of 4 interconnected hydrocarbon rings

Question 16

how many carbon atoms are in the rings of a steroid structure

Answer 16

three of the rings contain 6 carbon atoms and the fourth ring contains 5 carbon atoms

Question 17

what are anabolic steroids

Answer 17

hormones similar in structure to testosterone that promote muscle growth

Question 18

what happens to testosterone receptors with excessive anabolic steroid use

Answer 18

they may become desensitized leading the brain to stop producing natural testosterone

Question 19

what are the structural differences between saturated and unsaturated fats

Answer 19

saturated fatty acids: maximum hydrogen atoms, no double bonds, solid at room temperatures
monounsaturated fatty acids: one double bond, liquid room temperature, bent chain
polyunsaturated fatty acids: more than one double bond, liquid at room temperature, slightly bent chain

Question 20

what is the difference between cis and trans unsaturated fats

Answer 20

cis unsaturated fats have hydrogen atoms on the same side of the double bond, while trans unsaturated fats have them on opposite sides

Question 21

what are the outcomes of hydrogenation

Answer 21

makes fats more solid at room temperature and converts cis-bonds into trans-bonds

Question 22

what is margarine a result of

Answer 22

a result of hydrogenation and contains more trans fatty acids than butter

Question 23

from what molecule are steroids derived

Answer 23

cholesterol

Question 24

what are molecules made from steroids in the body

Answer 24

steroids
vitamins
bile salts

Question 25

what are the steps in fat digestion

Answer 25

1. fats must be emulsified with bile salts 2. emulsified fats are hydrolyzed into fatty acids 3. reassembled and packaged into lipoproteins (chylomicrons)

Question 26

what is the structure and function of lipoproteins

Answer 26

-Spherical molecules -Hydrophobic interior -Hydrophilic exterior with water-soluble proteins and phospholipids -Function: transport cholesterol and fats in the circulatory system

Question 27

What do chylomicrons do?


Answer 27

Chylomicrons enter the blood to deliver fats to the cells of the body.

Question 28

What is LDL?

Answer 28

LDL stands for low-density lipoprotein, which has very little protein.

Question 29

what happens when a person ingests more protein or carbs than required

Answer 29

the liver transforms excess protein or carbs into fats which are packaged as LDLs

Question 30

what is HDL

Answer 30

DL stands for high-density lipoproteins which have few lipids

Question 31

what are the functions of HDL vs LDL in the human body

Answer 31

LDL: carries triglycerides to the body's parts (bad cholesterol) HDL: picks up excess cholesterol and takes it to the liver (good cholesterol)

Question 32

what is the effect of diets high in trans fats on LDLs

Answer 32

diets high in trans fats impeded the uptake of LDLs by cells, causing them to circulate in the blood

Question 33

what is the relationship between LDL levels and cardiovascular disease at risk

Answer 33

the greater the amount of LDLs circulating in the blood, the greater the risk of cardiovascular disease

Question 34

what is he total blood cholesterol composed of

Answer 34

total blood cholesterol = HDL + LDL

Question 35

what are trans fats and their effects on cholesterol levels

Answer 35

trans fats raise LDL levels, reduce HDL levels and raise triglycerides in the blood

Question 36

what defines omega-6 fatty acids

Answer 36

Omega-6 fatty acids have a double bond that is 6 carbons away from the last carbon on the carbon skeleton

Question 37

what structures do phospholipids form in water

Answer 37

amphipathic: nonpolar hydrophobic tails and polar hydrophilic heads forms a bilayer

Question 38

what are the two lipids that make up the phospholipid bilayer

Answer 38

1. phosphoglycerides: glycerol, fatty acids, phosphate and alcohol 2. sphingolipids : sphingosone (long chain amino alcohol)

Question 39

in which cells are sphingolipids abundant

Answer 39

brain, nerves, lungs and spleen tissue

Question 40

what is Tay-Sachs disease related to

Answer 40

accumulation of sphingolipids in never cells due to a lack of the enzyme that breaks them down

Question 41

what type of allele is associated with Tay-Sachs disease

Answer 41

autosomal recessive allele coding for the enzyme that breaks down sphingolipids