Tuesday, November 27, 2012

Enzymes and their function


Chemical Reactions
A chemical reaction is a process that changes one set of chemicals into another set of chemicals.
Energy in Reactions
Energy is released or absorbed whenever chemical bonds form or are broken.
Because chemical reactions involve breaking and forming bonds, they involve changes in energy.

Because matter and energy are conserved in chemical reactions, every organism must have a source of energy to carry out chemical reactions.
Plants get their energy from the sun.
Animals get their energy from eating plants or other animals.  


Activation Energy
Chemical reactions that release energy do not always occur spontaneously.
Chemists call the energy that is needed to get a reaction started the activation energy.
What are Enzymes and how is it related to Activation Energy
Enzymes
Some chemical reactions that make life possible are too slow or have activation energies that are too high to make them practical for living tissue.
These chemical reactions are made possible by catalysts.
A catalyst is a substance that speeds up the rate of a chemical reaction.
Catalysts work by lowering a reaction's activation energy.
Enzymes are proteins that act as biological catalysts.
Enzymes speed up chemical reactions that take place in cells.
Enzymes act by lowering the activation energy




Notice the blue line is without an enzyme and red line if 
with the enzyme notice how the activation energy is lowered to 
start to reaction and thus the process of going 
from reactants to products if faster.

Enzymes are very specific, generally catalyzing only one chemical reaction.
For this reason, part of an enzyme’s name is usually derived from the reaction it catalyzes.
HOW DOES THIS WORK:
Enzymes act as a Lock and Key mechanism. The enzyme is the key. It only works with a specific substrate
The enzyme and substrates remain bound together until the reaction is done and the substrates are converted to products.
The products of the reaction are released and the enzyme is free to start the process again

  • Enzymes play essential roles in:
  • regulating chemical pathways.
  • making material that cells need.
  • releasing energy.
  • transferring information.









Wednesday, February 29, 2012

Genetically altered babies

Go to the following website. Whe you arrive their go click on the survey and complete the survey seperately. When the survey is completed on the bottom of the link it will say send to a friend (send to: mrharrell1914@gmail.com). Then read the background essay and answer the questions. Turn this in by the end of class.
http://www.teachersdomain.org/resource/tdc02.sci.life.gen.babiesbydesign/

Friday, February 10, 2012

Extra Credit Genetic Problems

Show your work: http://www.biology.arizona.edu/mendelian_genetics/problem_sets/monohybrid_cross/monohybrid_cross.html

Go to the following website and do problems 1,2,9,11,13. Show your work to get full extra credit. This is due on Tuesday morning. If you do not turn it in at the beginning of class then you will not receive extra credit. This is due 7:10am on 14 Feb 2012. Problems 1,2,9,11,13