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Warm-Up 10/2/16 Socrative Quiz on Chapter 3 Room Code: ZABLOTSKY320
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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.
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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.
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OH H HO CH2OH O Carbohydrates energy molecules
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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
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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)
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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)
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Time needed to digest depends on structure
slow release starch (plant) linear Energy Storage What does branching do? glycogen (animal) branched fast release
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Starch vs. Cellulose Molecular structure determines function in starch
in cellulose isomers of glucose structure determines function…
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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
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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
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Other Carbohydrates Chitin – modified polysaccharide
Used in fungi cell walls, arthropod exoskeletons, and dissolving stiched! Peptidoglycan – used in bacterial cell walls
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Lipids Energy storage Long term energy
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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
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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
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Building Fats Triglyceride 3 fatty acids linked to glycerol
ester linkage = between OH & COOH BIG FAT molecule!!
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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?
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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
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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?
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Saturated vs. unsaturated
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Phospholipids Structure: glycerol + 2 fatty acids + PO4
PO4 negatively charged
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Phospholipids Hydrophobic or hydrophilic?
fatty acid tails = hydrophobic PO4 = hydrophilic head Amphipathic Major component of cell membranes interaction with H2O is complex & very important!
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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…
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Steroids ex: cholesterol, sex hormones 4 fused C rings
different steroids created by attaching different functional groups to rings cholesterol
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Cholesterol Important component of cell membrane
helps keep cell membranes fluid & flexible
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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
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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?
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Questions?
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