1. Warm-Up 10/2/16
Socrative Quiz on Chapter 3
Room Code: ZABLOTSKY320

2. Warm-Up 10/4/2016 1. H+ + HCO3- H2O + CO2
The equation above shows one of the reversible reactions that occur in blood. After exercise, an athlete’s blood pH has dropped below the normal level. How will normal blood pH be restored?
a) An increase in O2 concentration in the plasma will lead to an increase in H+ concentration
b) An increase in temperature will lead to an increase in H+ concentration.
c) An increase in sweating will lead to a decrease in OH- and H+ concentration.
d) An increase in breathing rate will lead to a decrease in blood CO2 and H+ concentration.
2. Humans can digest starch but not cellulose because
a) the monomer of starch is glucose, while the monomer of cellulose is galactose.
b) humans have enzymes that can hydrolyze the beta (β) glycosidic linkages of starch but not the alpha (α) glycosidic linkages of cellulose.
c) humans have enzymes that can hydrolyze the alpha (α) glycosidic linkages of starch but not the beta (β) glycosidic linkages of cellulose.
d)humans harbor starch-digesting bacteria in the digestive tract.

3. Warm-Up 10/4/2016 1.) H+ + HCO3- H2O + CO2
The equation above shows one of the reversible reactions that occur in blood. After exercise, an athlete’s blood pH has dropped below the normal level. How will normal blood pH be restored?
a) An increase in O2 concentration in the plasma will lead to an increase in H+ concentration.
b) An increase in temperature will lead to an increase in H+ concentration.
c) An increase in sweating will lead to a decrease in OH- and H+ concentration.
d) An increase in breathing rate will lead to a decrease in blood CO2 and H+ concentration.
2. Humans can digest starch but not cellulose because
the monomer of starch is glucose, while the monomer of cellulose is galactose.
b) humans have enzymes that can hydrolyze the beta (β) glycosidic linkages of starch but not the alpha (α) glycosidic linkages of cellulose.
c) humans have enzymes that can hydrolyze the alpha (α) glycosidic linkages of starch but not the beta (β) glycosidic linkages of cellulose.
d) humans harbor starch-digesting bacteria in the digestive tract.

4. OH H HO
CH2OH O
Carbohydrates
energy molecules

5. General Info: “Sugars” & “Starches”
Carbohydrates are composed of C, H, O (1:2:1)
carbo - hydr - ate
CH2O
(CH2O)x C6H12O6
Function:
u energy u energy storage
u raw materials u structural materials

6. Monosaccharides & Disaccharides
Monomer: monosaccharide (hexose sugars)
Glucose, Galactose & Fructose
Combine 2 by dehydration synthesis, and you get a “disaccharide”
Glucose + Glucose = Maltose (from starches)
Glucose + Fructose = Sucrose (table sugar)
Glucose + Galactose = Lactose (milk sugar)

7. Polysaccharides Polymers of sugars Function:
costs little energy to build
easily reversible = release energy
Function:
energy storage
starch (plants)
glycogen (animals)
in liver & muscles
structure
cellulose (plants)
chitin (arthropods & fungi)

8. Time needed to digest depends on structure
slow release
starch
(plant)
linear
Energy Storage
What does branching do?
glycogen
(animal)
branched
fast release

9. Starch vs. Cellulose Molecular structure determines function in starch
in cellulose
isomers of glucose
structure determines function…

10. Digesting starch vs. cellulose cellulose hard to digest
starch easy to digest
It’s flat
enzyme
cellulose hard to digest
It’s rigid
enzyme
Starch = all the glycosidic linkage are on same side = molecule lies flat
Cellulose = cross linking between OH (H bonds) = rigid structure

11. The Problem of Herbivory
Herbivores need to digest cellulose
Animals lack the enzymes necessary to break beta linkages
Several Strategies
Caecophore
Cows
Termites
Expanded lower GI
Cannot regurgitate
Eats & Redigests poop!
Wood eater
Symbiosis w protist
Expanded upper GI
Bacteria + regurgitation

12. Other Carbohydrates Chitin – modified polysaccharide
Used in fungi cell walls, arthropod exoskeletons, and dissolving stiched!
Peptidoglycan – used in bacterial cell walls

13. Lipids
Energy storage
Long term energy

14. Lipids Lipids are composed of C, H, O 3 major groups
long hydrocarbon chain
3 major groups
fats
phospholipids
steroids
Do not form polymers
big molecules made of smaller subunits
not a continuing chain
Made of same elements as carbohydrates but very different structure/ proportions & therefore very different biological properties

15. Triglycerides: Structure: glycerol (3C alcohol) + fatty acid enzyme
fatty acid = long HC “tail” with COOH group at “head”
enzyme
Look at structure… What makes them hydrophobic?
Note functional group = carboxyl
dehydration synthesis

16. Building Fats Triglyceride 3 fatty acids linked to glycerol
ester linkage = between OH & COOH
BIG FAT molecule!!

17. Fats store energy Long HC chain Function: polar or non-polar?
Why do humans like fatty foods?
Long HC chain
polar or non-polar?
hydrophilic or hydrophobic?
Function:
energy storage
very rich
2x carbohydrates
cushion organs
insulates body
think whale blubber!
What happens when you add oil to water
Why is there a lot of energy stored in fats?
• big molecule
• lots of bonds of stored energy
So why are we attracted to eating fat?
Think about our ancestors on the Serengeti Plain & during the Ice Age. Was eating fat an advantage?

18. Saturated fats All C bonded to H No C=C double bonds
long, straight chain
most animal fats
solid at room temp.
contributes to cardiovascular disease (atherosclerosis) = plaque deposits
Mostly animal fats

19. Unsaturated fats C=C double bonds in the fatty acids plant & fish fats
vegetable oils
liquid at room temperature
the kinks made by double bonded C prevent the molecules from packing tightly together
Mostly plant lipids
Think about “natural” peanut butter:
Lots of unsaturated fats Oil separates out
Companies want to make their product easier to use:
Stop the oil from separating Keep oil solid at room temp.
Hydrogenate it = chemically alter to saturate it
Affect nutrition?

20. Saturated vs. unsaturated

21. Phospholipids Structure: glycerol + 2 fatty acids + PO4
PO4 negatively charged

22. Phospholipids Hydrophobic or hydrophilic?
fatty acid tails = hydrophobic
PO4 = hydrophilic head
Amphipathic
Major component of cell membranes
interaction with H2O is complex & very important!

23. Why is this important? Phospholipids of cell membrane
double layer = bilayer
hydrophilic heads on outside
in contact with aqueous solution outside of cell and inside of cell
hydrophobic tails on inside
form core
forms barrier between cell & external environment
Phospholipid bilayer
Note other molecules in membrane…

24. Steroids ex: cholesterol, sex hormones 4 fused C rings
different steroids created by attaching different functional groups to rings
cholesterol

25. Cholesterol Important component of cell membrane
helps keep cell membranes fluid & flexible

26. From Cholesterol  Sex Hormones
What a big difference a few atoms can make!
Same C skeleton, different functional groups
Cortisol – “stress hormone” – increases bp and blood sugar
Aldosterone – kidneys – help with Na+ and H2O retention. Sodium helps control blood pressure and regulates the function of muscles and nerves
Testosterone – male secondary sex characteristics
Estradiol - estrogen hormone – found in males and females
Progesterone – pro gestation – involved in menstrual cycle and pregnancy

27. Review: What are the monomers of carbs?
Which carbs are used for energy?
Which carbs are used for structure?
Which carbs make up exoskeletons?
What two units make up a lipid?
What units is a phospholipid made up of?
Which end of a phospholipid is hydrophobic?
Which end of a phospholipid is hydrophilic?
What is the distinctive structure of a steroid?
What are the two types of steroids?
What is the function of cholesterol?

28. Questions?