Energy and Chemical Rnx
• All Chemical reactions either produce or take
energy: Are exothermic or endothermic 
• In the body, ALL chemical reactions are
collectively called your METABOLISM
• There are 2 kinds of metabolic reactions
• Anabolic
or Catabolic
• (Anabolism)
(Catabolism)
Anabolism or Anabolic reactions
• **Energy storing, synthesis, (build up) RNX
ie: Production of protein, fat,
**Takes Energy to build up!!!!
**Requires Energy input =
ENDERGONIC/Endothermic
Catabolism or Catabolic reactions
**Energy releasing, decomposition, (break
down RNX ie: protein to aa, starches to
simple sugars.
** Gives off energy when breaking down
molecules!!!!
** Produces Energy = EXERGONIC/Exothermic
One Reaction feeds the other!!! Cyclic!
Protiens RUN OUR LIFE
• Proteins are a very diverse macromolecule and perform many
functions within our body!!
• 1. Provide Structure
•
EX: Keratin and Collagen
• 2. Carry our Communication
•
•
Ex: hormones, cell to cell signals, receptors, & reversibly
binding proteins called, Ligands
• 3. Membrane Transport
•
•
EX: protein channels in PM, carriers that bind solutes,
trigger nerve and muscle activity
• 4. Catalysis ENZYMES
• 5. Recognition and Protection
•
•
EX: Glycoproteins in immune function, Antibodies, Clotting
proteins
Enzymes and Metabolism
•
•
•
•
Enzymes are proteins that work as catalysts
Substrate is what is acted upon by the enzyme
Catalists facilitate molecular interactions!!
(They help biochemical reactions to occur more
rapidly under normal body temperatures)
• Enzymes lower activation energy to push
reactions involving substrates to go faster (with
more energy, more completely)
• Enzymes can help build substrates together or
help break substrates apart.
• Enzymes do not get consumed in the
Reaction!! They are available for re-use !!
They PUSH molecules together
They PULL molecules apart
• Sometimes enzymes have “helpers” called:
• Cofactors (iron, copper, zinc, mg, ca) these
cofactors stimulate proper folding
• Coenzymes (NAD+)….electron acceptors that
carry electrons from various metabolic
pathways to others.
Book
• Supplement these notes with your own from
the book on :
• pages 69, Metabolism
• Pages 77-80 Proteins
• Pages 80-82 Enzymes