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.
