Exam 2B

Question 1

Blood

Answer 1

aqueous solution that functions as a transport and distriubution system for the body

• delivers: nutrients, oxygen, minerals, metabolic products and hormones
• Removes waster

Question 2

Serum Vs plasma

Answer 2

Plasma
-aqueous solution obtains following centrifugation of blood treated with anticoagulants
Anticoagulants:
1)EDTA- ethylenediamine tera acidic acid prevents coagulation by chelating divalent cations (Ca2+ and Mg2+)
2)Heparin-prevents coagulatin by binding to thrombin
3) citrate- used when blood is transfused

Serum

• aqueous solution obtained following centrifugation of coagulate blood
• takes 30 to 45 mins

Question 3

Erythrocytes

Answer 3

RBC
transport Due to hemoglobin
-oxygen, CO2, and protons

Cellular remnant

• lack nuclei and other organelles
• hemoglobin synthesized prior to loss of organelles

Question 4

Metal Transport/ Storage Proteins

Answer 4

Albumin
Functions: protein reserve, osmotic regulator, transport protein

Transferrin (fe2+)
-transports ferric iron(fe3+)

Ferritin
-iron storage protein; measured to determine iron def

Question 5

Enzyme def

Answer 5

a protein or RNA molecule that catalyzes a biochemical rxn

Question 6

Properties of Enzymes

Answer 6

1) Active site- 3D pocket or cleft created by catalytic groups-R groups of amino acids interact together causing the protein to fold and forming tertiary structure
- speicfic for particular substrate/rxn
2) Enzyme helper molecules
- cofactor
- coenzyme
- prosthetic group
* *prosthetic group and coenzyme derivatives of vitamins
3) Catalytic efficieny
- increase rate of rxn over uncatalyzed rxn
- 100 to 1000 S -> P/sec
- turnover
4) regulation
- enzyme can be activated or inactivated
5) compartmentalization-E are localized in particular compartments within a cell

Question 7

Enzymes alter Rate but DONT

Answer 7

1) Enzymes do not change equilibrium of reaction
- amount of product is the same despite the prsecen/absene of enzyme
2) Rate is significantly different in enzyme catalyzed and uncatalyzed reactions
3) Enzymes accelerate the attainment of equilibrium but do not shift their position. The equilibrium position is a function of free energy difference between R and P

Enzymes accelerate reactions by lowering activation E (G=) by facilitating the formation of transition state

Question 8

Evidence of ES

Answer 8

1) Saturation of Active site by increasing [S]
- at constate [E], velocity increases with increasing substrate conc until a maximal velocity is reached
- at maximal velocity all sites are filled

2) X-ray Crystallagraphy
- structure of R group interactions of active site amino acids and substrate

3) Spectroscopic characteristics:
- changes in absorbance/ fluoresce upon mixing to substrate and E

Question 9

Enzyme Active site characteristics

Answer 9

1) 3D cleft formed by catalytic group-R groups that interact from a vast area on linear protein and causes the protein to form to tertiary structure
2) sepresents small amount of Total V
- remaining amino acids serve as scaffolding
3) creates a unique microenvrioment
- disclude h20 so create NONpolar enviroment
- Polar amino acids attain “special” properties
4) Binds substrate to enzyme by weak interactions: hydrophobic, H-bondnig, Van Der waals NOT COVALENT
5) has specificity of binding dependant on arrangement of atoms
- lock and key
- induced fit

Question 10

Basic Principles to stabilize transition States

Answer 10

BE CABAM

1) Binding Energies
2) Covalent catalysis
- active site contains a reactive group (nu-)that becomes covalently attached to substrate during the rxn
3) Generalized Acid/Base catalysis-molecule serves as a proton donor and receiver (His)
4) Catalysis by Approximation-2 substrates brought close to each other
5) Metal Ion Catalysis

Question 11

Oxyanion Hole

Answer 11

Stabilizes the tetrahedral intermediate of carbonyl carbon by stabilizing the negative charge on oxygen
-hydrogen bonding of H-N of peptide backbone

Question 12

Sigmoidal Curve activity in vivo

Answer 12

As substrate conc increases more enzyme binds to substrate and are transformed into R state, increasing the ability to bind even more substrate

Question 13

isozymes

Answer 13

or isoenzymes

• enzymes that differ in amino acid seq yet catalyze the same reaction
• exhibit different kinetic parameters (Km, Vmax, etc)

Question 14

Fat soluble vitamins

• coenzyme/prosthetic group
• function

Answer 14

FAT=Keisha Even Dick Aye?
A
-coenzyme; vison growth reproduction; liver
D
-1,25-dihydroxy-cholecalciferol
-absorption of calcium and P
E
-none
-lipid antioxidant

K

• none
• blood clotting

Question 15

Water soluble vitamins

• coenzyme/prosthetic group
• function

Answer 15

Connor Balls NEED Water
C-ascorbic acid
-none
-hydroxylation; antioxidant