Polysaccharides and Lipids

Question 1

4 Classes of Macromolecules?

Answer 1

1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids

Question 2

How are Macromolecules Assembled?

Answer 2

Dehydration (or Condensation) Rxns

Question 3

How are Macromolecules Broken Down

Answer 3

Hydrolysis Rxns

Question 4

Carbohydrates Function?

Answer 4

Energy source and structural support.

Structural: Beta glycosidic linkage
-Cellulose : (cell walls of plants)
-Chitin : (structural polysaccharide in animals and fungi)

Storage: alpha glycosidic linkage
-Starch (plants)
-Glycogen (animals)

Question 5

How are monosaccharides linked?

Answer 5

Via a glycosidic bond, which is a covalent bond and formed through a dehydration reaction.

Question 6

Starch

Answer 6

Storage polysaccharide in plants
-unbranched: amylose
-branched: amylopectin

Alpha glycosidic bond linkages

Question 7

Glycogen

Answer 7

Storage polysaccharide in animals
-stored in liver and muscle cells

Hydrolysis of this polysaccharide releases glucose when demand of sugar increases

Alpha glycosidic linkages

Question 8

Cellulose

Answer 8

Structural Polysaccharide of plants
Higher stacking due to less branching (harder to breakdown)

Beta glycosidic linkages

Question 9

Chitin

Answer 9

Structural polysaccharide in animals and fungi

-How arthropods (insects, spiders, crustaceans) build their exoskeleton

Beta glycosidic linkages

Question 10

Clicker:
You are studying a polysaccharide that contains unbranched B-glycosidic linkages and cannot be digested by humans. Which polysaccharide are you studying?

a. Cellulose
b. Amylose
c. Amylopectin
d. Glycogen

Answer 10

a. Cellulose

Question 11

Biological Functions of Lipids?

Answer 11

-energy storage
-thermal insulation
-hormone signaling
-membrane fluidity

Question 12

Lipid Characteristics

Answer 12

-Non-polar
-Hydrophobic
-Lipid chains held together via van der Waals force (stacking of lipid tails)-> these aren’t polymers because subunits aren’t covalently bonded. But LDF’s are additive.

Question 13

How are triglycerides formed?

Answer 13

Condensation (or dehydration) reaction
-ester bond formation

Question 14

Saturated Fat

Answer 14

No double bonds in hydrocarbon chain

Question 15

Unsaturated Fat

Answer 15

Double bonds in h-carbon chain
Cis conformation=naturally occurring

Question 16

Lipid Classes? (3 types)

Answer 16

1.) Triglycerides
hydrocarbons
non-polar
hydrophobic

2.) Phospholipids
amphipathic: contain hydrophilic and hydrophobic components.
*Phospholipid bilayer =essential to cell membrane structure

3.) Steroids
ex: cholesterol (component of animal cell membranes important to maintaining cell fluidity. Backbone structure of cholesterol=precursor to all other steroids)

Question 17

Clicker:
Would you expects the membrane composition of an arctic fish to have higher or lower levels of cholesterol compared to tropical fish?

Answer 17

Higher