Chemical reactions and enzymes 2.4. Chemical reactions Change one substance into another Involve...
-
Upload
archibald-martin -
Category
Documents
-
view
219 -
download
0
Transcript of Chemical reactions and enzymes 2.4. Chemical reactions Change one substance into another Involve...
Chemical reactions and enzymes2.4
Chemical reactions
• Change one substance into another• Involve changes to the chemical bonds that hold
molecules together
Energy in reactions
• Reactions that release E can happen spontaneously
• Reactions that absorb E can’t happen without an energy source (ex: the sun for photosynthesis)
Activation energy
• The energy needed to get a reaction started.
Enzymes
• Lower the activation energy
• Act as a catalyst• Not used up in the
reaction• Speed up chemical
reactions that take place in cells
How enzymes work
• The shape of the enzymes allow substrates (reactants) to bind to it
• While bound to the enzyme, the substrates react
• When the products are released, the enzyme is free to start the process overSucrase breaks apart sucrose
Enzymes
• Can make a reaction go 10 million times faster!
• Are very specific – only catalyze one reaction each
• Are affected by pH and temperature
• Are essential for life processes
Restriction enzyme binds to DNA (blue)
Enzyme from an Insect-eating plant
Human salivary amylase (spit)