PSL201Y1 Lecture Notes - Corticosterone, Fructose, Sertoli Cell

46 views5 pages

coppercattle724

13 Dec 2011

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

What commonalities are found in males: formation of gametes (sperm or oocytes, hypothalamic/pituitary control of reproduction a. Identical hormones in males & females (ghrh, lh, fsh: gametogenesis, occurs in ovaries or testes, gametes w 23 chromosomes are produced from cells in the gonads w 46 chromosomes. End up w same gentic info in daughter cells as parent cells. Mitosis vs meiosis: animations: http://highered. mcgrawhill. com/sites/0072437316/ student_view0/chapter12/animations. html, meiosis : duplication first then 2 cell divisions, dif line-up of chromosomes, end up w 4 cells from. Gnrh secreted in pulses from neuroendocrine cells in hypothalamus: pulsitile activity, electric from gnrh, 1. 5 pulses/hr in males travels to anterior secreting-neurons pit lh secretion pulses. Pulsatility critical for reproductive function maintains tissues" responsiveness for these hormones: must treat problems of secretion of these, regulated by hormonal feedback & higher hormones in pulsitile way like normal brain centres. Changes in females on monthly cycle (3. 5< pulses/hr)

Related Questions

Hi this is the introduction that I have written for my poster. Myposter is on the following URL (please have a look!).

http://i55.tinypic.com/e0g0w5.jpg

Please correct the introduction for any scientific or grammaticalerrors and give me your suggestions about this section as well asthe overall poster. Thanks

This is very important so if you are not good at it pleasedon't answer.

Here is the introduction :

Have you ever thought about why would thrilling rides getyou excited, make your heart racing orsometimes even make you start screaming from the depths of yourcore, forming a bead of sweat on your forehead?

Well, the answer lies in physics. These rides demonstratevery good examples of the physics laws and concepts involved innature and their affect on us in real life applications.

Height, weightlessness, high velocity, hugeacceleration, the sudden impulse and themomentary change in momentum, the work being done and the suddenchange in energy are all factors that contribute inmaking a thrilling ride an exciting one. Those factorsmake adrenalin concentrations in our body system increasecausing higher blood pressure thus stimulating theheart.. They also make the rider in a lot ofuncertainty and unexpected visual cues.

An example of a thrilling ride is the Giant Drop which isa freefall ride involving the drawing of an eight seat carriage bytwin cables to the top of the tower. After one minute full ofanxiety, the riders are plummeted down a height of 39 stories(almost 115m) then brought to a halt within meters from the groundby a sophisticated magnetic braking system.

A nuclear reaction is represented by an equation similar to theequation for a chemical reaction. An example of a nuclear reactionis the decay of radium into radon by the emission of an alphaparticle (a helium nucleus). The equation for this reactionis

^{226}_{\ 88}{\rm Ra}\; \rightarrow \, ^{222}_{\ 86}{\rmRn}+\;^4_2{\rm He}.

The superscript preceding each element indicates the nucleon numberof that particular nucleus (total number of protons and neutrons).The subscript indicates the charge of the nucleus, which is equalto the atomic number for nuclei. Nuclear reactions frequentlyinvolve electrons (sometimes called beta rays) and photons(sometimes called gamma rays). Electrons, which have nucleon number0 and charge -1, are represented in equations as either ^{\ \;0}_{-1}\beta or ^{\ \; 0}_{-1}{\rm e}. Photons are represented as^{0}_{0}\gamma to emphasize that they have no nucleon number andcarry no charge.

In nuclear reactions, several conservation laws are usuallysufficient to determine the products or reactants. One of these isconservation of nucleon number. The total number of neutrons andprotons in all of the reactants must be the same as the totalnumber of protons and neutrons in the products. Although protonsand neutrons sometimes change into one another, neither can simplydisappear. Another important conservation law is conservation ofcharge. The net charge of the reactants must be the same as that ofthe products.

Notice that, in our equation for the decay of radium, the sum ofthe nucleon numbers on each side is 226 and the sum of the chargeson each side is 88. If you knew everything in this equation exceptthe isotope of radon produced, you could simply subtract 4 from 226to find the nucleon number required to make the nucleon number ofthe products equal the nucleon number of the reactants. Similarly,if you knew everything in this equation except for the identity ofthe product element, you could simply subtract 2 from 88 and thenlook in a periodic table to find that the element with atomicnumber 86 is radon.

In parts A and B consider the decay of radon by alpha particleemission:

^{222}_{\ 86}{\rm Rn}\;\rightarrow\;X +\,^{4}_{2}{\rm He}.

a. What is the nucleon number of the element X?
Express your answer as an integer.

b. What is the atomic number (nuclear charge) of the elementX?
Express your answer as an integer.

n parts C and D consider the decay of Potassium-43 into calcium-43via the following reaction:

^{43}_{19}{\rm K} \rightarrow ^{43}_{20}{\rm Ca}+\,X.

c. What is the charge of the emitted particle X?
d. is not visible yet

E. An isotope of potassium with a half-life of roughly one billionyears is often used in radioactive dating. This isotope decaysthrough electron capture, the process of drawing an electron intothe nucleus. What is the chemical symbol for the element thatresults from this process? The equation for the reaction is

^{40}_{19}{\rm K}+\,^{\ \;0}_{-1}{\rm e}\rightarrow \,?.
Express your answer as a chemical symbol (e.g., Na forsodium).

f. The reaction energy of a reaction is the amount of energyreleased by the reaction. It is found by determining the differencein mass between the reactants and products and then using E=mc^2 toconvert the lost mass into the released energy.

Look again at the equation for the decay of radium (Ra), given inthe introduction. Use the following table of masses to determinethe reaction energy of this reaction.
Nucleus or particle Mass in atomic mass units
radium-226 226.025402
radon-222 222.017571
alpha particle 4.002602
Express your answer in joules to three significant figures.

please answer fully... thank you

PSL201Y1 Lecture Notes - Corticosterone, Fructose, Sertoli Cell

Document Summary

Get access

Related Documents

PSL201Y1 Lecture Notes - Lecture 12: Actin, Libido, Ultrastructure

PSL201Y1 Lecture Notes - Seminiferous Tubule, Sex Steroid, Spermatozoon

PSL201Y1 Lecture Notes - Oocyte, Endocrine System, Betabaculovirus

Related Questions