Biomolecules1. Describe the difference between a monomer and a polymer; give an example of a

monomer and a polymer (your example does not have to be a biomolecule).

2. Which polysaccharide (s) use(s) glucose as their building block? a. Cellulose

b. Glycogen

c. Starch

d. all of the above

e. none of the above

3. Why are human enzymes that digest starch unable to digest cellulose?

a. Cellulose is made of amino-containing sugars that cannot be metabolized.

b. Cellulose contains L-glucose instead of D-glucose; starch-digesting enzymes are specific for polymers of D-glucose.

c. Cellulose has beta-glycosidic linkages; starch-digesting enzymes cleave only alpha-glycosidic linkages.

d. Cellulose has beta-galactoside linkages that only bacterial beta-galactosidases can cleave.

e. Cellulose fibers are covalently cross-linked; starch-digesting enzymes cannot cleave these cross-links.

6 carbon sugars: hexose

Carbohydrate subunit

+

O O

HO HO

dehydration synthesis reaction

monomer monomermonomer

polymer

OH OH

2H2O

Starch vs glycogen

Starch vs glycogen

Starch vs cellulose

Chitin vs cellulose

Chitin

N*

N*

N*

N*

N*

N*

Biomolecules1. Describe the difference between a monomer and a polymer; give an example of a

monomer and a polymer (your example does not have to be a biomolecule).

2. Which polysaccharide (s) use(s) glucose as their building block? a. Cellulose

b. Glycogen

c. Starch

d. all of the above

e. none of the above

3. Why are human enzymes that digest starch unable to digest cellulose?

a. Cellulose is made of amino-containing sugars that cannot be metabolized.

b. Cellulose contains L-glucose instead of D-glucose; starch-digesting enzymes are specific for polymers of D-glucose.

c. Cellulose has beta-glycosidic linkages; starch-digesting enzymes cleave only alpha-glycosidic linkages.

d. Cellulose has beta-galactoside linkages that only bacterial beta-galactosidases can cleave.

e. Cellulose fibers are covalently cross-linked; starch-digesting enzymes cannot cleave these cross-links.

Biomolecules4. For each of the following, identify its structure and function:

Function:Short-term energyLong-term energy storage in plantsLong-term energy storage in animalsStructural support

Structure:MonosaccharideDisaccharidePolysaccharide

Glycogen

Glucose

Starch

Cellulose

Chitin

Lactose

Figure 3.12 Synthesis and breakdown of fat

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

+ 3

C

H

H

C OH

H

C OH

C OH

H

C C

H H

C

H

H

CO

C

H

H

C

H

H

C

H

HH H

O

C

C

O

C

H

H H H

C

H

C

H

C

H

H

CO

C

H

H

C

H

H

C

H

H

C

O

C

H

H H H

C

H

C

H

C

H

H

C

H

H

C

H

H

C R

R

R

H

H

C

H

H H H

C

H

C

H

C

H

H

C

H

H

C

H

H

C R

H

H

C

H

H H H

C

H

C

H

C

H

H

C

H

H

C

H

H

C R

H

H

C

H

H

C

H

C

H

C

H

H

C

H

H

C

H

H

C R

H

HH H

CO

+

dehydrationsynthesisreaction

3 Fatty acids Fat

hydrolysisreaction

3 Waters

H2O

C OHH

H

C OHH

C OHH

H

Glycerol

HO

HO

HO

Saturated vs unsaturated

Saturated vs. unsaturated straight vs. bent .

stacks well vs. not stack well

solid vs. liquid .

Trans fat

Figure 3.14 Phospholipids from

membranes

R

P

O

O O–

H

O

OC

O

HH

OC

polar head

non polar tails

phosphategroup

glycerol

fatty acids

inside of cell

b. Plasma membrane of a cella. Phospholipid structure

outside of cell

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HC

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HCH

HC

HCH

HCH

HCH

HCH

HCH

HC

HCH

HCH

HCH

CH

HCH

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

HCH

Sex steroids (hormones)

Corticosteroid (hormones):

control electrolyte and water levels

Immune system;Inflammation;carbohydrate, fat and protein metabolism

Bile acids: fat absorbtion

Cell membranes Vitamin D

3. All lipids

a) are made from glycerol and fatty acids.

b) contain nitrogen.

c) have low energy content.

d) are acidic when mixed with water.

e) do not dissolve well in water.

f) are hydrophilic.

3. All lipids

4. Assuming the fluidity of fish oils is comparable when observed in their natural

habitat conditions, then oils from arctic fish will have _______ than tropical fish oils.

a) more unsaturated fatty acids.

b) more cholesterol.

c) fewer unsaturated fatty acids.

d) more trans-unsaturated fatty acids.

e) more hydrogenated fatty acids.

1. A trans fatty acid is one

a. that has no carbon-carbon double bonds directly adjacent to each other.

b.that is a major component of phospholipids in cell membranes.

c. in which the hydrogens attached to adjacent carbons in a carbon-carbon double covalent bond are on opposite sides of the molecule.

d. in which the hydrogens attached to adjacent carbons in a carbon-carbon double covalent bond are on the same side of the molecule.

e. that is saturated with hydrogens.

2. Types of polyunsaturated fatty acids that are necessary in the human diet because they cannot be synthesized by the body are called _____________ fatty acids.

a. essential

b. important

c. trans

d. omega-3

e. hydrophobic

3. Generations of Americans were introduced to trans fats in their diet in the form of ____________ which was hailed as a healthy alternative to the saturated fats found in butter and lard.

a. Coconut oil

b. Olive oil

c. Margarine

d. Canola oil

» Beef tallow

1. HDL stands for

a. Highly dense lipid.

b. Hydrogenated dark lipid.

c. High density lipid.d. Hydrogenated dense lipoprotein.e. High density lipoprotein.

2. A triglyceride is composed of glycerol and three fatty acids. What type of reaction is used to link each of the fatty acids to a glycerol molecule?

a. Dehydration

b. Hydrolysis

c. Dehydrohalogenationd. Hydrogenatione. Hydroxylation

3. Which one of the following would be solid at room temperature?

a. Cis fatty acids

b. Corn oil

c. Peanut oild. Saturated fats such as lard (pig fat)e. Unsaturated fats

1. Which one(s) of the following diagrams represents a trans fatty acid?

2. Which one(s) is a saturated fatty acid?

(a) (b)

(c) (d)

(e) None of the above

1. Food companies can tag their products on the nutrition label as having 0g of trans fats if they have <0.5g of trans fat per serving. What could be found in the ingredients list that is probably a better indicator of the presence of trans fats in foods than the trans fat line on the nutrition label?

a. Lard

b. Hydrogenated oilsc. Palm oild. Olive oile. Almonds

2. Consumption of which of the following is most likely to raise your HDL and also lower your LDL levels?

a. Trans fats

b. Saturated fats• Lard• Polyunsaturated fats• Margarine