Tuesday, February 2, 2010
Tues-Day 2
Bio - we reviewed the breathing mechanism and how its rate is controlled by the level of CO2 in the bloodstream; we showed how this CO2 level is regulated via interactions between the medulla, diaphragm, and respiratory system.
We then looked at the rest of the excretory system, namely, the urinary system. The urinary system involves FILTRATION of metabolic wastes such as UREA and excess substances such as water and salts/ions from the blood by the KIDNEY (renal organ); this filtrate is called URINE which travels through URETER tubes, there are TWO ureters, one from each kidney. The urine collects and is temporarily stored in the URINARY BLADDER, until the bladder sufficiently fills at which point, the urine is passed through a SINGLE tube, the ureTHRA, at which point the urine is out of the body.
We saw that the functional units of the kidney are NEPHRONS. The nephron is a tube that is surrounded by capillaries. The wastes and nutrients DIFFUSE from the capillary blood into the nephron tube BUT THEN most of the nutrients are RE-ABSORBED back into the blood from the nephron tube BUT the wastes stay concentrated in the tube to form urine. The nephron does lots of active transport to concentrate the wastes in the urine and get the nutrients back into the blood.
The bottom line is that the concentrations of nutrients and ions, as well as the pH of the blood is REGULATED by the kidney.
AP Chem - we practiced the "quick method" of determining the rate law for a reaction from a data table containing varying reactant concentrations and their effect on the initial reaction rate. Each experiment in the table is conducted at the SAME TEMPERATURE so that the rate CONSTANT, k, will be the same for each experiment.
We then saw the formal method of calculating the exponent of each reactant by taking the RATIO of the rate laws between two experiments.
We then emphasized how to tell the difference between an intermediate and a catalyst, in a reaction mechanism both in the mechanism and on a potential energy curve for a given reaction.
We started a problem in which 3 proposed mechanisms were evaluated for consistency with an experimentally determined rate law.
# posted by C @ 1:43 PM 
