Exam 3

Can oxidation and reduction reactions occur independently of eachother?
No.
What is oxidation?
An electron loss. Addition of oxygen; loss of hydrogen.
What is reduction?
An electron gain. Loss of oxygen; gain of hydrogen.
Example of oxidation.
O
ll
R-C-OH
Example of reduction
OH
R- C- H
H
What carbon is the anomeric carbon?
The carbonyl group.
Where is the reacting oxygen for an anomeric carbon?
Last OH group on chain.
What is an alpha anomer?
OH points down.
What is an beta anomer?
OH points up.
What functional group is associated with a glysosidic bond?
Ether.
Where does the glycosidic bond occur?
Between the reacting oxygens of each cyclic hemiacetals.
What is the reducing end?
The free anomeric carbon.
What is the non-reducing end?
The occupied anomeric carbons.
What is a storage polysaccharide?
Only alpha-glucose units; ex: starch and glycogen.
What is a structural polysaccharide?
Only beta-glucose units; ex: cellulose
What are characteristics of glycogen?
Branched polymer of glucos units. Storage polysaccharide found in animals; stored in liver in muscles. When glucose is needed, glycogen is hydrolyzed in liver to glucose.
Where are oligosaccharides found?
On the surface of red blood cells.
What is a monosacchride?
One carbohydrate.
What is a disacchride?
Two carbohydrates.
What is a oligosaccharide?
Group of carbohydrates up to 9.
What is a polysaccharide?
Group of carboyhydrates starting at 10 and up to 10,000.
What do monosaccharides contain?
Both primary and secondary alcohols.
What is an aldose?
A carbohydrate containing the algehyde functional group.

O
ll
R-C- H

What is a ketose?
A carbohydrate containing the ketone functional group.

O
ll
C-C-C

What are the two types of carbohydrates?
Aldose or ketose.
What are classifications for monosaccharides?
Triose, tetrose, pentose, hexose.
What are stereoisomers?
Mirror images of eachother.
What are enantiomers?
Mirror images of each other.
What is a L enantiomer?
OH group on left.
What is a D enantiomer?
OH group is on right.
What is a diasteromer?
Only one or more of the chiral carbons has been changed.
What are characteristics of glucose.
Most abundant monosacchariade in nature. Dextrose, blood sugar, broken down in cells for energy, found in milk and sugar, glycogen and starch.
Structure of Fructose.
CH2OH
C = O
HO + H
H + OH
H + OH
CH2OH
Structure of Glucose.
O
ll
C – H
H + OH
HO + H
H + OH
H + OH
CH2OH
Characteristics of amylose.
Part of a starch mixture that also contains amylopectin. Contains D-glucose unites bonded in a containue chain. Tend to coil like a telephone cord.
Chracteristics of amylopectin.
80% plant starch. Branching occurs.
How does pKa relate to the strength of an acid?
The smaller the pKa the stronger the acid.
What is the relationship between pKa and pH?
If pKa > pH, take H+. If pKa < pH lose H+.
What is produced during a peptide bond?
Water.
Why do polypeptides fold up?
So that the nonpolar areas interact with each other and the polar areas interact with water.
What are the four levels of structure in a protein?
Primary, seconday, tertiary, and quarternary.
What are the two substructures of the secondary structure protein?
Alpha helix and beta pleated sheet.
What stablizes secondary structures?
Hydrogen bonding.
How is the tertirary structure of a protein structured?
So that the nonpolar side chains are on the interior and the polar side chains on the surface with water.
What stablizes the tertiary structure of a protein?
Attractive forces between the side chains and aqueous environment. And attractive forces between the side chains themselves.
What are some of the attractive forces in a tertiary structure?
London forces, hydrogen bonding, dipole-dipole, ion-dipole, salt bridges, and disulfide bonds.
What stablizes a primary structure protein?
Peptide bonds.
What stablizes a quarternary structure protein?
Same as tertiary.
What are globular proteins?
Compact, spherical structures that are soluble in aqueous environment.
What are fibrous proteins
Long, threadlike with high helical content.
Characteristics of hemoglovin.
Example of 4 subunits forming quaternary structure. Each subunit contains a nonprotein part called the prosthetic group called a heme.
What does the heme do?
Binds an Fe2+ which binds O2
What are some functions of proteins?
Transport oxygen in blood. Components of skin and muscles. Defense mechanisms against infections. Biological catalysts called enzymes. And control metabolism of hormones.
What does the order of amino acids in protein determine?
The structure and biological function.
What is an L amino acid?
Protonated amine on left.
What is a D amino acid?
Protonated amine on right.
What are the four categories for amino acids?
Nonpolar, polar, acidic, and basic.
What are the 10 essential amino acids?
Valine, leucine, isoleucine, phenylalanine, methionine, typtophan, threonine, histidine, lysine, and argainine.
What can be synthesized in the body from metabolic precursors?
Nonessential amino acids.
Can dietary amino acids be stored?
No.
Why are essential amino acids important?
They can not be synthesized in the body and they cannot be stored.
What is a buffer?
A solution that contains conjugate acid/base pairs that will resist a change in pH to solution.
Why are buffers useful in the body?
They help our bodies maintain the proper pH in the bloodstream.
What is respiratory acidosis?
Not enought CO2 expelled, buildup occurs. More acid produced to lower pH. More H3O+, more acidic, lower pH.
What is respiratory alkalosis?
Too much CO2 expelled, removed acid, raising pH. Lowering concentration of H3O+, more basic, higher pH. (paper bag)
What is the K, equilibrium expression?
K = (reactants)/products) (dont forget coefficent as exponents)
What does it mean is K = 1?
Equal amounts of products and reactants.
What does it mean if K > 1?
Products favored.
What does it mean if K < 1?
Reactants favored.
How does Ka value relate to acids?
Large the Ka value the stronger the acid. (as opposed to pKa)
What is the equation relating pH to H3O+?
pH = -log (H3O+)
What does pKa give the ratio of?
The ratio of conjugate base and hydronium ion to weak acid.
What does pH tell you?
How much hydronium ion is present in solution.
If pH < pKa
Acid is greater.
if pH = pKa
acid and base is equal.
If pH > pKa.
Base is greater.
What is the definition of an acid?
Donates protons.
What is the definition of a base?
Accepts protons.
What are neutralization reactions?
Acid/base reactions that react to form a salt and water.
What is a big difference in how strong acids react compared to weak acids?
Strong acids ->. Weak acids reversible.
What are the primary structural components of cell membranes?
Phospholipids.
What are phospholipids?
The primary structural components of cell membranes.
What is an isotonic solution.
When the concentrations of solutes in the solution are the same on both sides of the membrane.
What is a hypotonic solution.
Concentration of solutes outside the cell is low while the concentration of solutes in the cell is high.
What is a hypertonic solution.
Concentration of solutes outside the cell is high while the concentration of solutes inside the cell is low.
What is the net flow of solution across the cell membrane?
Net flow is from lower concentration to higher concentration.
What are the common physiological solutions?
0.90 % m/v NaCl. and 5% m/v D-glucose.
What is diffusion.
The net movement of molecules from area of high concentration to area of low concentration.
1 ppm =
1 ppm = 1 mg/liter
1 ppb =
1 ppb = 1 Ug/liter