| Question |
Answer |
| Bond dissociation Energy |
The energy required to break or make a chemical bond. |
| Activation Energy |
The minimum energy required by reacting molecules. |
| Spontaneous reactions |
Exothermic, ∆H is greater than the Ea |
| Non-spontaneous reactions |
Endothermic, ∆H is less than the Ea |
| If Ea is increased what happens to the number of particles? |
The number decrease |
| If Ea is increased what happens to the reaction rate? |
The rate decreases |
| If the Ea is decreased, what happens to the reaction rate? |
The rate is increased! |
| Is the effect of a change in Ea on the reaction rate a linear or exponential change? |
Exponential! |
| Catalysts |
Lower the Ea, speeds up reaction, can be used to regulate kinetics. |
| Vmax |
The maximum concentration of a substrate where it will have an effect on the velocity. |
| Steady State Approximation |
The ES Complex tends to decay as fast as it forms. |
| Michaelis- Menten Constant |
Utilized as a measure of the affinity of an enzyme for its substrate. Predicts how velocity is related to [S] if [enzyme] is held constant. |
| If you have a smaller Km, what can you tell abou the enzyme, and reaction rate? |
More effective enzyme, faster reaction rate. |
| Enzyme |
Biological catalysts. |
| Lineweaver-Burke Equation |
A linear presentation of the kinetic response for an enzyme catalyzed process. |
| Competitive inhibition |
A molecule (inhibitor) chemically resembles the substrate, so the enzyme gets “confused.” This slows down the rate of reaction because less enzyme is reacting with the substrate. |
| Why is it called competitive inhibition? |
The inhibitor is occupying the catalytic sites, therefore there is competition for the catalytic sites. |
| What do you do to reverse competitive inhibition |
Increase [S], causing a shift to the right towards the ES complex. |
| Non-Competitive Inhibition |
A molecule (inhibitor) reacts with an area remote from the catalytic site. This permanently reduces Vmax. |
| What is a characteristic of a NC inhibitor? |
Heavy metal ions. |
| Where does the NC inhibitor bind to? |
Non-catalytic sites. |
| How can you reverse NC inhibition? |
Add Chelating Agents |
| If there is a change in Vmax, what sort of inhibition is the process? |
Non Competitive |
| Irreversible Inhibition |
A rapid process that is deleterious to the gross organism. |
| Adenisine Tri Phosphate (ATP) |
A nucleotide, that contains an N - base, a pentose and phosphate groups. |
| ATP + Water = ? |
ADP and Inorganic phosphate |
| What is the ∆G of hydrolysis of ATP? |
-31 KJ |
| What is Gibbs Free Energy (∆G) |
A measure of the maximum magnitude of the net useful work that can be obtained from a reaction. |
| What does it mean of ∆G is negative? |
Spontaneous reaction/ product favored |
| What does it mean if ∆G is positive? |
Non-spontaneous reaction/ reactant favored. |
| 1st law of thermodynamics |
The energy change of a process is equated to the heat evolved and the work done by that process.
∆E = Q + W
|
| 2nd law of thermodynamics |
To order a random system, work must be done. The universe tends towards disorder. |
| Entropy (∆S) |
The measure of randomness or disorder in a system. |
| What is the relationship between entropy and probability of a system? |
the more random = the more probable (and the more spontaneous) |
| Free energy change of a process |
∆G = ∆H - T∆S |
| Cellular Energy Conversions |
The conversion of reducing power to phosphate power (ATP) |
| Outer Membrane of mitochondria |
Mostly permeable |
| Inner Membrane of mitochondria |
Difficult to permeate, defines matrix, uses pumps and gates. |
| Pyridine- Linked Dehydrogenase |
An enzyme (therefore, a protein), NADH or NADPH (dinucleotide active forms of Niacin)
|
| Flavin-Linked Dehydrogenase |
An enzyme (protein), FAD or FMN – co factors, Manifestations of Riboflavin |
| Cytochromes |
Organo-metallic containing polypeptides. Chelating Agents. |
| What is the typical structure of a cytochrome? |
Heme structure - a ring with coordinate covalent bonding. |
| Non- Heme Iron Proteins |
• A polypeptide with iron, but no organic substructure (heme)
• The iron is locked in by coordinate covalent bonds
|
| Co-Enzyme Q |
• Not a polypeptide
• Can be a redox
• Found in all aerobic organisms
|
| NADH + H+ + ½ O2 → NAD+ + H2O |
Electron Transport |
| What is the gibbs free energy of electron transport? |
-220 kJ |
| What is the ultimate electron acceptor? |
OXYGEN!!! |
| Chemiosmotic Hypothesis |
For oxidative phosphorylation to occur, the mitochondrial membrane must be continuous and it must have a matrix or it cannot create a gradient! |
| What is the effect of uncouplers? |
make the mitochondrial membrane porous to protons → continue to burn fuel, but produce no ATP (increased inefficiency) |
| If you run out of ATP and O2 consumption stops, what can you add to restart O2 consumption? |
ADP |
| What happens if you add rotenone to the system? |
O2 is no longer being consumed. |
| What can you add to reverse the effects of rotenone? |
Succinate |
| What does oligomycin do to the system? |
Stops consumption of O2 |
| What can be done to reverse the effects of oligomycin? |
2,4 DNP |
| What is the most permanent way to stop consumption of oxygen? |
add Cyanide. |
Biology Lab Midterm
