Download Biochemistry - CPBiologyMTHS

Energy and Enzymes
 When one or more substances change to create
one or more different substances.
 Old bonds are broken and new bonds are
formed.
 Activation Energy :
 an amount of energy required to get a reaction
started.
 Often, the amount of energy needed to start a
reaction is very high and the reaction itself takes a
long time.
 takes a lot of energy to break bonds and the
molecules have to come together in the right way
 ANIMATION: Why Enzymes
 Catalyst:
 1. Speeds up a reaction by lowering the activation energy
 2. Not consumed by the reaction
 ENZYMES are catalysts in living things
 1. protein or RNA molecule (organic contains C)
 2. Speeds up chemical reactions
 3. Not consumed by the reaction
 Most reactions are slow or require more
energy than can be produced inside the body.
 A catalyst is essential for metabolism to work.
 Enzymes fit (like a lock and key) with a
substrate.
 Substrates are the reactants of a
chemical reaction.
 An enzyme is shaped very specifically to
react with only its substrate.
 ANIMATION: Specificness
 1. Enzyme binds to substrate
 2. Enzyme/Substrate complex
forms
 The enzyme “hugs” the substrates
 3. New Product(s) form and are
released
 *** What do you notice about the
enzyme to the right???
 It is NOT CHANGED!
 Animation: Reusing Enzymes
 LOCK and KEY example which is
enzyme and which substrate?
 Enzymes require specific
environments. (THINK
HOMEOSTASIS!!)
Lost Homeostasis
 Temperature
 pH
 Salts
 If the enzymes environment
changes – then the shape
changes (DENATURES)
which results in NO
REACTION!
 Substrate no longer fits.
 cannot react with its other
reactants
 the reaction stops.
 Animation: Denaturing
 Milk/Egg Demo
In Homeostasis
Letters = reactants and products
Numbers = enzymes
1
2
AB C
SO what does this mean…”If an enzyme is missing or not
functioning properly, then homeostasis is lost.”
Examples:
1. no vital product made (C) ex) insulin
2. accumulation of a toxin (B) ex) PKU disease