
smallest basic particle is the atom
› Electrons- negatively charged
› Protons- positively charged in nucleus
› Neutrons- uncharged in nucleus
when electrons are lost or gained, a
charge occurs
 substances containing only one kind of
atom are called elements

approximately 20 elements are found in
all living things
 carbon, hydrogen, oxygen, and nitrogen
make up 97%
 the other 16 are called trace elements


Molecules are when two or more atoms
are joined together (Ex: O , CO )
2
2
Two or more atoms or molecules joined
in a definite proportion by weight is
called a compound
 Compounds have different
characteristics from elements they are
made from
 Represented by a formula

Two or more atoms or molecules joined
in a definite proportion by weight is
called a compound
 Compounds have different
characteristics from elements they are
made from
 Represented by a formula


Types of Compounds
› Inorganic
 Do not contain carbon
 Often has a metal as a positive ion
› Organic
 Found in living things
 Always contain carbon
 When with hydrogen they are called
hydrocarbons (usually gases)
 When with other carbons, they bond in chains

Solutions
› Chemical process take place in solutions
› A solution is when one substance dissolves
into another
› The solute is dissolved into the solvent
› If it dissolves it is soluble, if not, insoluble
› Note: in microbiology, a tincture is alcohol
and some other substance
All have carbon (C), hydrogen (H), and
oxygen (O)
 Occur in ration of 1:2:1


Monosaccharides
› Single or simple sugars
› Glucose, fructose, galactose
› They are isomers (same formula, but different
arrangement)

Glucose (also known as dextrose)
› Carried in bloodstream
› Combines with oxygen (oxidation) and
produces adenosine triphosphate (ATP)

Fructose (found in fruits and honey)
› Sweetest of all monosaccharides

Galactose
› Found in small amounts in agar, flaxseed,
and milk
NOTE: “ose” means sugar

Disaccharides
› Known as a double sugar
› Examples: sucrose(table sugar), lactose (milk
sugar)and maltose (malt sugar)

Chemical reaction to join:
› Dehydration synthesis (opposite to break
apart is hydrolysis)
+
=
Disaccharide
Disaccharide +
=

Oligosaccharides
› Form chains called polymers
› Small chains with only 2-10 monosaccharides
› Ex: insulin

Polysaccharides
›
›
›
›
Large, complex molecules
Made of hundreds of thousands of glucose
Have very long polymer chains
Ex: starch, cellulose, and glycogen

https://www.youtube.com/watch?v=M6
ZLDJluj6I

http://www.khanacademy.org/partnercontent/crash-course1/crash-coursebiology/v/crash-course-biology-103
Examples are fats, oils, and waxes
 Like carbs, they have carbon, hydrogen,
and oxygen, but much less oxygen
 Fats are solid and oils are liquid at room
temperature
 Better sources of energy than
carbohydrates (yield more energy) but
are harder to oxidize
 Three groups: simple lipids, compound
lipids, and derived lipids

Simple Lipids (triacylycerol or triglyceride)
 contain one glycerol molecule and
three fatty acids held together by ester
linkages
 Formed by
dehydration
synthesis
Simple Lipids
 Saturated (when all carbon bonds are
single and saturated with hydrogen)
› Can block arteries
› Difficult to break up
› Raises cholesterol
› Solid at room temperature
Simple Lipids
 Unsaturated (when two or more hydrogen
bonds are replaced with double bonds
between carbon atoms)
› Liquid at room temperature
› Monounsaturated (lacks 2 hydrogen bonds) or
Polyunsaturated (lacks 8 or more hydrogen
bonds forming 4 or more double bonds)
› Lowers Cholesterol
› Easier to break up

Trans Fats
› Unsaturated fat but act like a saturated fat
› Has trans arrangement in bonding- the
hydrogens are on opposite sides of the
double bond.
› Typical man-made
https://www.youtube.com/watch?v=3xF_L
K9pnL0
https://www.youtube.com/watch?v=VGH
D9e3yRIU

Compund lipids- lipids which contain an
inorganic or organic group in addition to
fatty acids and glycerol.
› Phosphpholipids- Lipids containing a phosphate
group. A phospholipid molecule has a strongly nonpolar
and hydrophobic (water insoluble) tail region represented
by fatty acid chains and a strongly polar or hydrophilic
(water soluble) head region represented by the
phosphate group.
› Glycolipids- These are lipids containing a
carbohydrate group, usually galactose. They
are found in the nerve cell membranes
especially in the myelin sheath.
› Lipoproteins- These are lipids, usually
phospho-lipids which contain a protein
molecule. They occur in the cell membrane.
They are also found in milk and egg yolk

Derived Lipids (Sterols)
› Contain only carbon, hydrogen, and oxygen
› Include steroids found in male and female
hormones, Vitamin D, cholesterol, and fat
soluble vitamins A, E, and K
› Classified as lipids only because they are
soluble in fat solvents
› These are lipids that do not have a straight
chain. They are composed of four fused
carbon rings and a long hydrocarbon side
chain.

Derived Lipids
Contain hydrogen, oxygen, and nitrogen
and most times phosphorus and sulfur
 Found in every part of living cells
 Coat viruses
 In binding and structural components
like fingernails, hair, ligaments, muscles,
etc.
 Made of AMINO ACIDS


Structure of Amino Acid
Position 1 is carbon, Position 2 is amino group (NH2), Position 3 is
hydrogen atom, Position 4 is a carboxyl group (COOH), and
Position 5 is variable (R)
Ex: Glycine (H is in R group)
Large protein molecules are constructed from any
number and sequence of amino acids (can number
from 300 to thousands)

Amino acids linked by dehydration
synthesis (C-N) (bond between carboxyl
group of one amino acid and amino
group of next amino acid). Called a
PEPTIDE BOND and a series of linkages is
called a POLYPEPTIDE

THIS IS CALLED A PROTEIN

Structure
› Primary- straight chain
› Secondary- helix
› Tertiary- twisted and folded
› Quaternary- two or more polypeptide chains
are bonded together
http://www.youtube.com/watch?v
=lijQ3a8yUYQ
https://www.youtube.com/watch
?v=2Jgb_DpaQhM
Functions:






Enzymes - proteins that allow chemical reactions to
occur in living things
Antibodies – proteins that protect the body from
infection
Structure – cytoskeleton, hair, nails, muscles, spider
web, silk, feathers ,horns, hooves etc….
Hormones – chemical messengers
Cell membrane – proteins can act as channels through
the cell membrane
- receptor proteins found on membrane
transmit signals to the inside of cells
Hemoglobin – protein found in blood that carries oxygen
Denatured proteins are proteins that lose their shape
- if they lose their shape, they also lose their
- What can cause a protein to become denatured?
Exposure to: Strong Acid
Strong Base
Heat
Organic solvent: Alcohol or Acetone
- Denatured proteins can lose quaternary, tertiary
and secondary structure
- Primary Structure is left untouched
Specialized proteins
 Help provide energy to cell at just the
right moment and at just the right speed
 Also known as organic catalysts
 Highly specific
 Very large and complex

Made of either all protein or part protein
(apoenzyme)attached to a non-protein
part (coenzyme)
 Coenzymes could be calcium, iron,
magnesium, copper, or vitamins like C
and B-complex

The localized site on the enzyme
molecule is called the active site
 Each enzyme has its own pattern on the
active site (no 2 alike)
 An enzyme reacts with a reactant whose
molecular pattern fits the enzyme’s
molecular pattern.
 The molecule that the enzyme reacts
with is called a SUBSTRATE molecule


Temporary physical binding called
Enzyme-Substrate
Complex
Enzymes are proteins and if they are
exposed to extremes of temp or pH lose
their shape
 - if a protein loses its shape, it loses its
function
 - a protein that loses its shape is said to
be denatured
 - if an enzyme is denatured, substrate
cannot enter the active site
extreme
temperatures
or pH
Name usually ends in –ASE
 Added to stem word taken from
substrate
 Examples:

› Lactase……lactose
› Lipase……...lipids
› Maltase……maltose
› Protease…...protein
› Sucrase…….sucrose
An example in microbiology:
Many bacteria have an enzyme that
needs a compound called PABA (paraaminobenzoic acid). PABA helps bacteria
make a vitamin called folic acid, which
the bacteria need to grow.
An example in microbiology:
When antibiotic sulfanilamide is given to
the bacteria instead of PABA, the
sulfanilamide molecules attach to active
sites of bacteria and folic acid is not made.
Contain carbon, oxygen, hydrogen,
nitrogen, and phosphorous
 Two types- DNA and RNA


DNA
› Found in chromosomes and genes, plasma
membrane, mitochondria, and chloroplasts
› Consists of a phosphate group, deoxyribose
sugar and one of four nitrogenous bases:
adenine, thymine, cytosine, and guanine

RNA
› Consists of a phosphate group (ribose
sugar), and any of the following nitrogenous
bases: adenine, cytosine, guanine, and
uracil
› Single stranded
› Found in cytoplasm, nucleoli, and ribosomes
› Two kinds: mRNA and tRNA