Properties of Biological Molecules Flashcards
What is the Second Law of Thermodynamics
The total entropy of a system plus that of its surroundings always increases. Entropy may be decreased locally if entropy of universe is increased by an equal or greater amount
What is the First Law of Thermodynamics?
Total energy of a system and its surrounds are constant. Energy is neither created or destroyed
Purpose of Glycolysis
Generating energy to maintain ionic disequilibrium to allow for continued electrical depolarization
What drives a reaction?
- Increase the concentrations of reactants
2. Decrease the concentration of products
What is Mass Action
Le Chatelier’s Principle which is the concept of concentration driving the reaction
Free energy is spontaneous when?
Delta G is negative and energy is released and spontaneous
What is the free energy equation?
Delta G = Delta H - T(Delta S)
Give an example of a covalent bond. What is the strength of covalent bonds
C-C bond and it is the strongest bond
What makes a bond strong
The amount of energy that must be expended to break them
What are electrostatic interactions. Give the equation
A charged group of one molecule atracts an opposite charge of another
kq1q2/Dr
In the equation E = kq1q2/Dr, What is the relation of r to E. What is the relation of D to E
R is the distance between two charges. As distance gets closer the greater the energy. Greater the D the lower the E
E=kq1q2/Dr What does the D mean
D is Dielectric concentration of the solvent, the environment. If the environment is water the water is polar (80) its going to diminish the E. Bigger D smaller E. But hydrophobic world is the D is small so E is up (Hexane 2)
Hydrophobic Effect
Water does not like to interact with hydrophobic molecules. Forms a crystalline structure around the droplet and is almost like ice.
Van der Waals Interactions
The basis of a van der Waals interaction is that the distribution of electronic charge around an atom fluctuates with time.
Hydrogen Bonds
These interactions are fundamentally electrostatic interactions.
2 properties of water
- Water is a polar molecule - asymmetric, bent
2. Highly cohesive - interact strongly with one another
Thermodynamics vs Reaction Velocity
Thermo - Whether the reaction will proceedwithout the input of energy, not indicative of velocity
Velocity - Reaction velocity is increased bya catalyst – an enzyme
Acid-Base Reactions
– Weak acid dissociates in water, releasing a proton and its conjugate base
– Weak base combines with protons in water, forming itsconjugate acid
What is pH
The concentration of hydrogen ions in solution
pH = -log(H+)
pH of 7.0 is equal to….
pH 7.0 refers to a solution for
which −log[H+] = 7.0, and so log[H+] = −7.0
and [H+] = 10log[H+] = 10^-7 = 1.0 × 10−7 M.
Equilibrium constant (k) for the dissociation of water is equal to ?
1.8x10 ^-16
=[H+][OH−]/[H2O]
What is the Henderson–Hasselbalch equation?
pH = pKa + log([A−]/[HA])
Why is pH range for blood and inside the cell = 7.36-7.43?
Proteins must maintain structure and function
Describe the acid levels in blood when hyperventilating
When hyperventilating-it is alkolosis and pH goes up. Increasing the rate loss of CO2. carbon dioxide is a by-product of metabolism, and carbon dioxide combines with water to form carbonic acid. Rapid elimination of acidic products of metabolism results in alkalosis
What is a buffer? Give an example
Substance that will keep the pH from changing. Bicarbonate can pick up a proton if protons are added to keep the protons being added to the solution. It can also add a proton to a solution. Reversibly bind protons and has a pK
Hypo-ventilating causes pH to….
Lower. Failure to eliminate acidic products of metabolism results in acidosis
What happens to pH when one vomits vs has diarrhea?
Vomit burns because of stomach acid so rapid loss of acid causes alkolosis
Diarrhea causes bicarbonate to be lost so acidosis
When is the buffer at its maximum?
When pH = pKa
When pH is lower than pKa then
the acidic form is in higher concentration and there is high affinity (not give up proton very easily until the pH gets to the pK value)
When pH is higher than the pKa then
It is more deprotenated and low affinity
If H2PO4 goes to HPO4. Which one is the conjugate acid making the other the conjugate base?
HPO4 is the conjugate base (A-)
H2PO4 is the conjugate acid (HA)
What is Delta G 0 Prime?
Laboratory value that is determined. Standard free-energy change. Delta G 0 Prime = -RT ln K’eq
pK of a carboxyl group has high or low pK
low
The pK for a amine group has a low or high pK?
High
