Thursday, January 28, 2010
Thurs-Day 1
Bio - we reviewed the structures of the respiratory system and then discussed how the features of each structure enabled its function of efficiently getting oxygen into the blood.
We then discussed the breathing mechanism: how contractions of the diaphragm and intercostal muscles cause the chest cavity to expand/increase in volume thus LOWERING the air pressure in the lungs causing air to move into the lungs (from the now higher pressure external environment) i.e. "inspiration". As the diaphragm and intercostal muscles relax, the chest cavity gets smaller thus INCREASING pressure on the lungs thus squeezing/forcing the air out to the external environment i.e. exhalation.
We did a combined circulatory and respiratory system, blood circulation and gas exchange activity. We saw how this complex yet coordinated complex causes carbon dioxide to be delivered to the lungs and excreted while oxygen diffuses into the blood at the lungs and is transported to all of the body's cells.
AP Chem- we reviewed reaction rates and their expressions and reviewed the meaning of the fraction that shows "rate of change" of a given substance.
We discussed chemical reaction mechanisms in terms of order, molecularity, and probability of multiple-molecule collisions.
We related the raw rate data to the graphs of concentration vs. time. Then, taking data from several different concentration vs. time graphs for a given reaction, we saw the plot of INITIAL RATE vs. INITIAL CONCENTRATION in order to determine the "order" of the reaction with respect to a given reactant. The "order" of the reaction (the exponent given to the substance to make the initial rate vs. initial concentration graph a STRAIGHT LINE) indicated the NUMBER of those reactant molecules involved in collisions in the slowest/rate determining step of the reaction mechanism.
See Blackboard for further tutorials.
# posted by C @ 9:18 PM 
