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Cellular Processes
Bioenergetics and Water/Acids and Bases
34
Biology
Professional
11/09/2009

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Cards

Term
What is the first law of thermodynamics?
Definition
Energy can be converted between forms but can't be created or destroyed
Term
What is the second law of thermodynamics?
Definition
Entropy, S, of the system must increase for a process to occur spontaneously
Term
What does Gibbs Free Energy represent?
Definition
Total energy available for the system to do work
Term
What are the 2 equations for free energy? What is the equation for standard free energy?
Definition

ΔG = ΔH - TΔS = ΔG° + RTln ([C][D]/[A][B])

 

ΔG° = -RTln(Keq)

Term
How can a reaction be coupled?
Definition
Through a common intermediate:
A + B -- C + D is coupled to
D + E -- F +G

If the addition of the two reaction has a negative ΔG then the reaction is spontaneous
Term
What bonds are high energy in ATP and why?
Definition
Bond between gamma and beta phosphates and between beta and alpha

High Energy:
1. More resonance structures in hydrolyzed form
2. Electrostatic repulsion of negative charges (stored electric potential)
3. Improved solvation effects and increased degrees of freedom of products
Term
How can ATP be stored?
Definition
ATP stored in Phosphagens such as phosphocreatine mediated by creatine kinase. High [ATP] drives reaction toward phosphocretine. Low [ATP] drives reaction back to give more ATP
Term
What does hydrolysis mean?
Definition
Donation of phosphate to water
Term
What is the common intermediate in phosphototransfers involving an enzyme?
Definition
The transition state where both ATP and acceptor are bound in the enzyme, making this complex the intermediate and coupling the reactions
Term
What gives the highest energy for a hydrogen bond?
Definition
co-linear and optimum distance (2-3 Å). Hydrogen bonds are made and broken every 10^-12 seconds. Each water has 4 partners
Term
What are the colligative properties or water?
Definition
Properties not dependent on mass or size but concentration of solvents
1. Freezing point depression
2. Boiling point elevation
3. Osmotic pressure
4. Reduced vapor pressure
Term
What drives salts to dissolve in water?
Definition
Entropy is increased when salts are dissolved. Enthaply difference is lessened by formation of H-bonds. Ions become spheres of hydration where point charge is dissipated (molecular basis for dielectric constant D)
Term
What are the two major functions of dielectric constant?
Definition
1. carry electrical current
2. Dissolve polar molecules
Term
What are electrolytes?
Definition
Substances that dissociate in water into a cation and anion
Term
What are weak electrolytes?
Definition
Do not completely dissociate in water (many organic molecules)
Term
What is Kw or Water?
Definition
Kw = K'eq * [H2O] = [H+] + [OH-]= 10^-14
Term
What is an acid?
Definition
Proton donor
Term
What is a base?
Definition
proton acceptor
Term
What form of an acid or base can penetrate cell membranes?
Definition
Non-ionized form. (important for drug absorption)
Term
What is the Henderson-Hasselbalch eqn?
Definition
pH= pKa + log([Base]/[Acid])
Term
Where is the best buffering range for a particular conjugate pair?
Definition
at +/- 1 of pKa
Term
What is the equilibrium equation for CO2 in water?
Definition
CO2 + H2O = H2CO3 = H+ + HCO3-

CO2 can be considered and acid
Term
How do the lungs compensate for metabolic acidosis?
Definition
Decrease pCO2 through increase ventilation
Term
What is the general structure of an amino acid?
Definition
α carbon has amino group, carboxyl group, hydrogen, and R side change attached to it
Term
What is the R group for Glycine?
Definition
-H
Term
What is the R group for alanine?
Definition
-CH3
Term
What is the R group for cysteine?
Definition
-CH2-SH
Term
What is the R group for Serine?
Definition
-CH2-OH
Term
What are the non polar amino acids?
Definition
Methionine, alanine, valine, leucine, isoleucine
Term
What are the polar amino acids?
Definition
Arginine, Lysine, Glutamic acid, Aspartic acid, Glutamine
Term
What are the acidic amino acids?
Definition
Glutamic acid and aspartic acid?
Term
What are the basic amino acids?
Definition
Histidine, Lysine, Arginine
Term
Which form of the amino acid is found in proteins?
Definition
L-amino acid
Term
Where are strongly polar amino acids found and where are hydrophobic amino acids found?
Definition
Polar amino acids found on surface of protein. Hydrophobic amino acids found on interior of protein
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