Four Types of
Organic Molecules
Made by cells
Contains carbon
Importance of Carbon
Although cells are 70-95% water, the rest
is composed mainly of carbon compounds.
Proteins, carbohydrates, DNA, and other
molecules are compounds of carbon
bonded to other elements.
Carbon often bonds to H, O, N, S, and P in
organic compounds.
Properties of Carbon
Has four valence electrons; can form
covalent bonds with four other atoms
(tetravalence)
Carbon bonded to four atoms forms a
tetrahedron-shaped molecule.
Carbon can form single, double, or triple
bonds with other atoms.
Carbon chains form the backbone of most
organic molecules.
Chains can be straight, branched, or
arranged in closed rings.
Hydrocarbons contain carbon and
hydrogen only, and are hydrophobic. H—C
and C—C bonds are nonpolar.
Hydrocarbons make up fossil fuels, and
parts of cellular organic molecules such as
fats and phospholipids.
1. Carbohydrates- used as fuel and
building material
2. Lipids-energy storage
3. Proteins-structure, movement, enzymes
4. Nucleic acids-store and transmit
hereditary information.
All four are macromolecules because of
their large size.
The largest
Macromolecules
are called polymers
Created by linking
smaller subunits
called monomers.
Dehydration
Monomers are linked together to form
polymers through dehydration reactions,
which remove water
Monomers are linked together by covalent
bonds
Short polymer
Dehydration
reaction
Longer polymer
Unlinked
monomer
Hydrolysis
Polymers are broken apart by hydrolysis,
the addition of water
Breaks covalent bonds between
monomers
Hydrolysis
1. Carbohydrates
monosaccharides - one ring sugars

glucose, galactose and fructose
* A 6-carbon sugar
* Found in peas.
* A 6-carbon sugar
* The sugar in our blood
* A 5-carbon sugar
* the sugar that sweetens fruit
Diabetes
Disease characterized by high levels of
blood glucose resulting from defects in
insulin production
Monitored with blood glucose device.
disaccharides - two monosaccharides (2 ring
sugar)
Glucose + fructose = Sucrose (table sugar)
Glucose + galactose = Lactose (milk sugar)
Glucose + glucose = Maltose (malt sugar)
Lactose intolerant
If the enzyme lactase is not present, the body is unable to
break down lactose. Allowing it to reach the large intestines.
Normally, sugars do not reach the large intestine. This is what
causes a stomach ache!
polysaccharides - long chains of repeating units of
monosaccharides, these are energy storing
molecules or structural molecules
Energy:
starch (plants produce for a storage molecule.)
 glycogen (storage molecule in muscle and liver cells.)
Structural:
 chitin (used by insects and crustaceans to build an
exoskeleton.)


cellulose (plants produce for cell wall construction.)
indigestible because we lack enzymes to break it down.
Starch, Cellulose & Glycogen
All the sugars
are oriented in
the same
direction
Branched or
"forked"
Every other
sugar molecule
is "upside-down
Review Q:
Polymers of carbohydrates are all
synthesized from monomers by
A) the joining of disaccharides.
B) hydrolysis.
C) dehydration synthesis.
D) ionic bonding between monomers
E) cohesion.
2. Protein
Made of a long chain of amino acids
Make up 50% of cellular dry weight
Amino acids (building blocks)
Have an amino group and a carboxyl group
Also a chemical group symbolized by R
Amino
group
Carboxyl
group
–
Dehydration reaction links the carboxyl group
of one amino acid to the amino group of the
next amino acid
– The covalent linkage resulting is called a peptide
bond
Carboxyl
group
Amino
group
Dehydration
reaction
Peptide
bond
Dipeptide
Amino acid
Amino acid
Proteins function as…
Support

keratin for hair and nails & collagen for
ligaments, tendons, skin
Proteins function as…
Enzymes to speed up reactions
Example: Amylase is an enzyme in saliva
that breaks starch into glucose monomers.
Saliva
Saliva Identification - Amylase
Proteins function as…
Transport across cell membranes

Hemoglobin
Defense from infection

Antibodies
Hormones

Insulin
Insulin is a hormone
that helps your body
use glucose.
Protein
structure is
key to their
ability to
function.
**A protein can be denatured,
heat causes it to lose its shape,
and its functionality..
Review Q:
The linkage between the monomers of
proteins are identified as
A) Peptide bonds
B) Glycosidic linkages
C) Ionic bonds
D) Covalent bonds
E) Ester linkages
Review Q:
Which two functional groups are always
found in amino acids?
A) Carboxyl and sulfhydryl
B) Carbonyl and carboxyl
C) Carboxyl and amino
D) Alcohol and aldehyde
E) Ketone and sulfhydryl
3. Nucleic Acids
Stores information
Two types:
DNA
(deoxyribonucleic acid)

RNA
(ribonucleic acid)

Nucleotides are
the building
blocks of
Nucleic acids.
4. Lipids
Hydrophobic – Will not mix with water
Types of Lipids:
 Phospholipids - form cell membranes
The polar heads are
towards the water,
the nonpolar tails are
on the inside of the
cell.
 Steroids cell messengers
 examples: testosterone, estrogen
 Waxes protection & waterproofing
 Triglycerides fats and oils

fats are made of chains of fatty acids
Saturated & Unsaturated
Saturated - no double bonds

solid at room temperature
Unsaturated - have double bonds

liquid at room temperature
Review Q:
Which macromolecule is the main
component of cell membranes?
A) Glucose
B) Steroids
C) Carbohydrates
D) Phospholipids
E) DNA
Review Q:
Which of the following macromolecules below
could be structural parts of the cell, enzymes,
or involved in cell movement or
communication?
A) Nucleic acids
B) Proteins
C) Lipids
D) Carbohydrates
E) Minerals