BIO 361 FINAL

• Each 100 ml if blood delivers much more oxygen during vigorous exercise than during rest.
• When the blood starts at a high partial pressure of oxygen, its partial pressure must fall greatly for oxygen to be released.
• When the blood is already at a lowered partial pressure, its partial pressure must only fall a little to release the same amount of oxygen from the blood.
• Hemoglobin exhibits more cooperativity and can unload a lot of oxygen at a much higher oxygen partial pressure.
• Myoglobin shows no cooperativity, and requires a very low oxygen partial pressure to release its oxygen.
• Myoglobin has a very high affinity for oxygen.
• P50 is the partial pressure of oxygen at which a pigment is 50% saturated shifts.
• A right shift means that the oxygen partial pressure needed to saturate is higher, and P50 is higher while oxygen affinity is lower.
• Affinity for oxygen decreases as blood pH decreases, shifting the oxygen equilibrium curve to the right.
• CO2 is also transported bound to hemoglobin (as carbamate).
• Carbonic anhydrase catalyzes the reaction between CO2 and H20.
• CO2 is mainly transported as bicarbonate ion in the blood.
• The Clbicarbonate counter transporter increases the ability of red blood cells to transport CO2.
• The H+ -binding capacity of hemoglobin increases the CO2 carrying capacity of blood.
• Individuals acclimatize or acclimate to environmental temperature.
• Acclimatize is a chronic response.
• Populations adapt to environmental temperature.
• Acclimatization is the response to natural environment.
• Acclimation is a response to a lab/controlled condition.
• Adaptation is an evoluntionary response.
• In partial compensation, after body temperature decreases, it increases during acclimation but does not return to the original level.
• During full compensation, after body temperature decreases, it increases during acclimation and reaches the original levels.
• Compensations occur over different timeframes: seasonally and over generations.
• Compensation adjusts enzyme activities aka Vmax.
• Kcat is the efficiency of the enzymes or the catalytic rate constant.
• Kcat requires different protein structures.
• An efficient enzyme must be flexible so that it can make more sensitive changes.
• Cold compensation is limited.
• Cold-induced increases in viscosity may limit protein flexibility and activity.
• Cold-induced increases in oxygen concentration are compensated by an increase in viscosity, reducing the diffusion coefficient of oxygen and limiting metabolic rates.
• Enzyme reactions require conformational changes to bind the substrate and cofactor.
• Organisms are sensitive to temperature change because it changes enzyme conformation.
• An enzyme that is too rigid can't bind the substrate.
• Enzymes that are too fluid also can't bind a substrate.
• The correct function of biological macromolecules requires accuracy, efficiency, and responsiveness which depends on the correct fluidity.
• Thermal stability of eye lens proteins correlates with body temperature.
• Increase is Km is a decrease in substrate-enzyme affinity.
• An increase in Km will cause reaction velocities to be lower.
• The active site of an enzyme must bind the substrate.
• The hinge regions of an enzyme must be sufficiently flexible for protein to flex and bind substrate.