Name ____________________________________________ Date ________________ Period ______
Chemical Reactions and Enzymes Notes
Chemical Reactions
• A process that changes one set of chemicals into another set of chemicals.
• Involves breaking bonds of the _________________.
• And forming bonds in the__________________.
• Example: carbon dioxide entering the bloodstream.
CO + H O
2
2
H CO (converts carbon dioxide into carbonic acid)
2
not
water
soluble
3
highly water soluble
Energy in Reactions
• Energy is either _________________ or ____________________ whenever
chemical bonds are formed or broken.
• Chemical reactions that release energy may occur spontaneously.
• -__________________—example: respiration, energy released in
form of ATP
• Chemical reactions that absorb energy will not occur without an source of
energy.
• ___________________—example: photosynthesis, energy input in
form of sunlight
Activation Energy--The amount of ________________ required to get a reaction
started.
• A catalyst is a substance that ____________ the rate of a chemical reaction.
Unit 2 Ecology: Chemistry of Life
Chemical Reactions and Enzymes
1
Name ____________________________________________
Enzymes
• Enzymes are _________________s that act as biological
___________________.
• Enzymes speed up chemical reactions that take place in cells.
• Enzymes work by lowering the _______________________________.
• ________________ the activation energy effects how quickly the reaction is
completed.
Enzyme Action
• Enzymes provide a __________ where reactants can be brought together to
react.
• The reactants of enzyme catalyzed reactions are called ________________.
• The substrate(s) bind to the site on the enzyme called the
___________________.
• Once the reaction is complete, the products of the reaction are
_________________ and the enzyme is free to _______________ the process
over again.
Unit 2 Ecology: Chemistry of Life
Chemical Reactions and Enzymes
2
Name ____________________________________________
Enzyme Action
Regulation of Enzyme Activity
• Enzymes can be affected by any variable that influences chemical reactions
including _________ and ___________________________.
• Most cells contain ________________________ that help turn key enzymes
“on” and “off” at critical stages in the life of the cell.
• Enzymes play essential roles in ___________________________ chemical
pathways, making materials that cells need, releasing _____________, and
transferring _______________________________.
Unit 2 Ecology: Chemistry of Life
Chemical Reactions and Enzymes
3