2.3 - 2.5 Study Guide
2.3—Carbon Compounds

Monomer – small repeating units

Polymer – large molecules

Polymerization - process that joins small repeating units (monomers) together to form large molecules
(polymers)
o
Dehydration synthesis - removes water (dehydration) to make a bond (synthesis)
o
The opposite process is Hydrolysis


Hydrolysis adds water (hydro) to break a bond (lysis)
There are 5 important carbon-based molecules in all organisms
1) Carbohydrates
2) lipids
3) nucleic acids
4) protein
5) ATP
MOLECULE
Carbohydrates
PICTURE
ELEMENTS
C,H,O
MONOMERS
POLYMERS
USE
Monosaccharides Polysaccharides Quick
energy
source in
body
Lipids
C,H,O
Glycerol
Fatty acids
Fat, lipid
Long term
energy
source in
body
Nucleic acids
C,H,O,P,N
Nucleotides
Nucleic Acid
DNA
RNA
Instructions
to make
proteins in
body
Proteins
C,H,O,S,N
ATP
C,H,O,P,N
Amino acids
---
Polypeptides
Proteins
---
Many uses:
movement
(muscle),
structure,
ENZYMES!!
Major
energy
carrying
molecule in
cell
2.4—Chemical Reactions
o Reactants—what goes into a reaction
o

Products—what comes out of a reaction
Depending on the change in energy, two different
reactions can occur
o Endothermic reactions absorb more energy than they release
o Exothermic reactions release more energy than they absorb
2.5—Enzymes
 Sometimes reactions happen too slowly for our bodies 

catalyst substance that speeds up a chemical reaction by decreasing the activation energy needed
o
Catalysts are not used up in a reaction
o
In our body, we have protein-based catalysts called enzymes


UNDERSTAND THE FOLLWOWNG CONCEPTS
For a chemical reaction to work, the substrate(s) (reactants) must attach to the active site on the
enzyme.

The shape of an enzyme is crucial to how it functions
o Referred to as the lock and key model

Enzymes (and proteins) can easily be deactivated if their shape
changes due to changes in the environment
o pH, and temperature changes can affect the shape of
the enzyme.