Integrated
Science
Chapter 6:
Chemistry in Biology
Atoms
 The
building blocks of matter
Atoms
Protons
 Positive (+)
 Inside the
nucleus
 Mass of 1
Neutrons
 No Charge
 Inside the
nucleus
 Mass of 1
Electrons
 Negative (-)
 Outside the
nucleus
 No mass
Elements
A
pure substance that cannot be broken
down.
 Most commonly found in living things are
CHONPS.
Compounds: a pure substance
formed when two or more different
elements combine.
Examples:
 H2 O
 NaCl (salt)
 CH4 (Methane gas)
Organic compounds
•
•
A compound containing Carbon
• Exceptions: CO2 CO CaCO3
All living organisms are made up of
organic compounds
Organic Compounds
•
•
Carbon = 4
covalent
bonds
Carbon can
bond to itself
• Results in a
variety of
important
organic
compounds
Organic Molecules
•
Carbon based molecules
form straight chains,
branched chains and rings.
Macromolecules: four classes
of organic compounds
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic
Acids
Macromolecules
Polymer = many units
Monomer = one unit
Carbohydrates
 carbon,
hydrogen and oxygen
 Includes sugars, starches and
cellulose
• Uses
• Energy storage
• Build cell walls
• Usually end in “-ose”
Monosaccharide
•
•
Single (simple) sugar
Monomers of carbohydrates
•
Ex: Glucose (energy in cells)(from the sun),
•
Fructose(fruit sugar),
•
Galactose
Disaccharides
Double sugar
• C12H22O11 (sucrose)
• Example:
•
Sucrose
•
Lactose
(milk sugar)
•
Polysaccharides
•
•
•
Many sugars
Starch- plants
Glycogen- animal starch
cellulose
•
•
•
Long chains of starch
Very strong
Function: plant cell walls
Lipids
What are they?
 Fats,
oils, waxes,
steroids
Function
 Energy
storage
 Insulation
 Cell membrane
 Coatings
 Hormones
Lipid Structure
Triglyceride =
Glycerol
3 Fatty Acid Chains
Saturated vs. Unsaturated Fats
Lipids
 Saturated
 Solid
 Straight
 Unsaturated
 Liquid
 Bent
What are trans fats?
(isomer)
Chemically altered unsaturated fats
Not found in nature
Your body doesn’t know how to break them down
Phospholipid function
 Phospholipid
bilayer in the cell membrane
Steriods
Proteins
 Contain
C, H, N, O (S)
 Enzymes (Amylase)
 Antibodies
 Hormones-regulate body
functions (insulin)
Types of Proteins
1.
Structural:
1.
2.
2.
Contractile
1.
3.
Keratin (hair, nails)
Collagen
Actin/myosin (muscles)
Pigments (skin, hair, iris)
Protein Structure
 1.

Amino Acids
20 different kinds
What are enzymes and why
are they important?
 Specialized
proteins.
 Speeds up a reaction (not consumed)
How do enzymes work?

Enzymes bind with a substrate and break it
into two or more products.
What are some examples of
enzymes?





Lipase – breaks down fat
Helicase- unwinds DNA
Amylase – breaks down food in your mouth
DNA Polymerase- assemble nucleotides in
DNA replication
Pepsin – breaks down proteins
What do all Enzymes have in
common?
 1.

Active Site
Location that the substrate binds to.
What do all enzymes have in
common?
 2.Very


specific
Lipase only breaks down fat
Helicase unwinds DNA for replication
What do all enzymes have in
common?
 3.


Recycled
Can be used over and over
Only a small amount is needed to speed up
thousands of reactions.
What is activation energy?
 Amount
reaction
of energy needed to start a
How do enzymes affect
activation energy?
 Enzymes
lower activation energy
How is enzyme activity affected by pH?
 Too
high/low = denatures
How is enzyme activity affected by
temperature?


Too high = denatures
Too low = inactive
How is enzyme activity affected by
enzyme concentration?

More Enzymes = faster rate of reaction
How is enzyme activity affected by
substrate concentration?
 The
rate of reaction will gradually increase
until it levels off.
The Enzyme Song
 https://www.youtube.com/watch?v=deF
QhPurj-k
Nucleic Acids
DNA
 Contains
hereditary info
(genes)
 Double helix
RNA
 Protein
synthesis
 Single helix
Flow of information
 DNA
→
RNA
→
Proteins