http://www.bowdoin.edu/biochemistry/information/images/chloroa-bowdoin-biochemistry.jpg
CHAPTER 3
Biochemistry
SECTION 1 PRETEST
Organic Compound
 Functional Group
 Monomer
 Polymer
 Macromolecule
 Condensation
Reaction
 Hydrolysis
 ATP

A. A simple molecule that
combines with other
molecules to make a larger
molecule
B. The main energy molecule for
organic processes.
C. Reaction when two molecules
combine to produce water.
D. The portion of a molecule that
is active in a chemical
reaction
E. Carbon containing compound
F. A large molecule formed
when smaller units combine
G. Chemical reaction involving
water and another substance
to produce something new
H. Very large molecules formed
from hundreds or thousands
of atoms
ANSWER KEY
Organic Compound
 Functional Group
 Monomer
 Polymer
 Macromolecule
 Condensation Reaction
 Hydrolysis
 ATP

E
D
A
F
H
C
G
B
THE ELEMENT OF LIFE: CARBON

Carbon is regarded as the
element of life
Organic Compounds —contain
carbon (and hydrogen)
 Carbon can form the large,
complex molecules common to all
living things because of its
structure.
 Carbon has 4 electrons in its
outer shell. The shell can hold 8.
Carbon needs 4 more electrons to
become stable, creating up to
four covalent bonds.

http://www.chemistrydaily.com/chemistry/upload/d/d9/Covalent.png
Carbon also has a tendency to bond with itself.
 This can result in big biological molecules based
around chains or rings of carbon atoms.

http://www.succeed.ufl.edu/content/abe2062/lect/lect_02/3_01.gif
Many complex biological molecules will be formed
using double and triple covalent bonds.
 Double —share 2 pair of electrons
 Triple —share 3 pair of electrons

Each line represents a covalent
bond. Carbon must have four
covalent bonds—or four lines
FUNCTIONAL GROUPS
Functional group —the
portion of a molecule that
is active in a chemical
reaction and that
determines the properties
of many organic
compounds.
 Example


Hydroxyl
OH
Makes molecules polar, this
means they are hydrophilic
(soluble in water)
 Called alcohols

Functional Group
Hydroxyl
(Alcohols)
Carbonyl (on end)
(Aldehydes)
Carbonyl (in middle)
(Ketone)
Carboxyl
(Organic Acids)
Amino
(Amino Acids)
Phosphate
(Nucleic Acids)
Structural Formula
-OH
H
- C=O
O
C
COOH
NH2
PO42-
Example
LARGE CARBON MOLECULES

The building of large molecules occurs as follows:

Monomers —small, simple carbon molecules

Polymers —consists of repeated, linked monomers

Macromolecules —large polymers:
(Carbohydrates, lipids, proteins, nucleic acids)
http://kenpitts.net/bio/human_anat/monomer.jpg
CONDENSATION REACTIONS
Polymers form during condensation reactions
 In these reactions; water is released

Example: Glucose and Fructose combine to form Sucrose
HYDROLYSIS
Polymers break down by a hydrolysis reaction
 In these reactions; water is used

http://imcurious.wikispaces.com/file/view/hydrolysis_reaction.jpg/113609729/hydrolysis_reaction.jpg
THE ENERGY MOLECULE: ATP

Adenosine triphosphate (ATP) —a molecule
that stores a large amount of energy in its overall
structure.
This is a major source of energy for most living cells
 Named the “energy currency” for living cells
because it is nearly a “universal molecule of energy
transfer” in living things
 Energy can be stored as carbohydrates or lipids, but
that energy (in chemical bonds) must be transferred
to ATP before it can be used in the cell

STRUCTURE OF ATP

ATP is made of “Adenine” and “Ribose” and
three phosphate groups
Adenine = nitrogen containing compound
 Ribose = 5-carbon sugar
 Phosphate groups = PO4
http://www.bio.miami.edu/~cmallery/150/metab/sf6x1a.jpg
The Hydrolysis of ATP is used by the cell to
provide the energy needed to drive chemical
reactions.
 It happens according to the following diagram:

http://kentsimmons.uwinnipeg.ca/cm1504/atp.htm
-ATP can lose its end phosphate which releases the energy stored in it
and makes adenosine diphosphate (ADP).
-This energy is used to do work in the cell.
-Adding the phosphate back to make ATP requires that we add energy
SECTION 2 PRETEST
 Carbohydrate
 Monosaccharide
 Disaccharide
 Polysaccharide
 Protein
 Amino
acid
 Peptide bond
 Enzyme
 Substrate
A. Organic compound made of amino
acids
B. Organic compound made of carbon,
hydrogen and oxygen
C. Proteins that speed up chemical
reactions.
D. Simple sugar
E. Double sugar
F. Buiding blocks of proteins
G. Holds amino acids together when
forming proteins
H. Sugar formed from three or more
monosaccharides
I. The reactant in a chemical
equation that is acted upon by
enzymes
 Active
site
 Lipid
 Fatty
acid
 Phospholipid
 Wax
 Steroid
 Nucleic Acid
 DNA
 RNA
 Nucleotide
J. Unbranched carbon chains that make
up lipids
K. Type of lipid forming protective layers
on plants and animals
L. Type of lipid found in many hormones
M. Deoxyribonucleic acid
N. Folds found in enzymes that fit into
a specific substrate
O. Ribonucleic acid
P. Large organic compounds that do not
dissolve in water
Q. Type of lipid found in the cell membranes
of living things.
R. Large organic compounds that store and
transfer information in cells
S. Part of a DNA molecule
ANSWER KEY









Carbohydrate
Monosaccharide
Disaccharide
Polysaccharide
Protein
Amino acid
Peptide bond
Enzyme
Substrate
B
D
E
H
A
F
G
C
I
Active site
Lipid
Fatty acid
Phospholipid
Wax
Steroid
Nucleic Acid
DNA
RNA
Nucleotide
N
P
J
Q
K
L
R
M
O
S
THE MOLECULES OF LIFE

Four main groups of organic compounds:
Carbohydrates
 Proteins
 Lipids
 Nucleic Acid

http://ez002.k12.sd.us/Chapter%20One%20Science.htm
CARBOHYDRATES
Composed of carbon, hydrogen and oxygen
 Make up about 1% of a cell
 Used for energy and structural materials
 Three types:




Monosaccharides —simple sugar
Disaccharides —double sugar
Polysaccharides —three or more monosaccharides
Monosaccharides —Contain C,H and O in a ratio of
1:2:1 (CH2O)n Note: N = whole # from 3-8
 Examples

Glucose (energy for cells)
Fructose (fruit sugar)
Galactose (milk sugar)
Note: All three have the
same molecular formula
C6H12O6 just different
structures therefore they
are called isomers
Disaccharides —two monosaccharides combine
in a condensation reaction.
 Example: Sucrose (table sugar)


Formed when glucose and fructose combine
Sucrose
Example: Glucose and Fructose combine to form Sucrose
Polysaccharide —three or more
monosaccharides form a much more complex
molecule.
 Examples:

Glycogen —hundreds of glucose molecules joined in
a large branching chain. Stored in the liver and
muscles of most animals and is used for quick energy
 Starch —glucose molecules joined together and
stored in plants for energy.
 Cellulose —thousands of glucose molecules joined
together in a straight chain. Provides the structure
for plant cell walls

PROTEINS
Composed of C, H, O and N
 Make up about 15% of a cell
 Found in hair, horns, skin, muscles, and enzymes
 Chains of amino acids (building blocks of proteins)

20 different amino acids with similar structures
 Only their R group varies
 The R groups determine their different shapes and functions

Carboxyl Group
http://cornellbiochem.wikispaces.com/23.2

Dipeptide —two amino
acids joined by a
peptide bond.


Peptide bonds are
formed by condensation
reactions in which water
is released
Polypeptide —long
chains of amino acids.
They fold and bend
themselves into large
protein molecules.
Temperature and
solvent type can
influence the shape of
proteins.
Ex: egg whites

Enzymes —special types of proteins that act as
catalysts
http://intranet.broadfordsc.vic.edu.au/yr12biol/enzymes_as_biological_catalysts_files/image003.gif
The enzyme can attach only to a substrate (reactant) with a specific shape.
The enzyme changes and reduces the activation energy of the reaction
so reactants can become products.
The enzyme is unchanged and is available to be used again.
LIPIDS
Composed of C, H and O —but in a higher ratio
of carbon and hydrogen atoms to oxygen atoms
than carbohydrates have: therefore, they store
more energy
 Make up about 10% of a cell
 Used to store extra energy and in cell membranes
 Nonpolar —do not dissolve in water
 Most are made of fatty acids bonded to other
molecules
 Examples: triglycerides, phospholipids,
steroids, waxes, and pigments

FATTY ACIDS
To fully understand how lipids work, we need to
first understand their fatty acid component
 Fatty acids —long, unbranched carbon chains
with a carboxyl group on one end.

Carboxyl end = polar and reacts with water
(hydrophilic “water loving”)
 Hydro-carbon end = nonpolar and does not react
with water (hydrophobic “water fearing”)

http://library.med.utah.edu/NetBiochem/mml/fa_polypatt01.gif
Saturated Fatty Acids —each carbon is covalently
bonded to four atoms (NO DOUBLE BONDS)
 Unsaturated Fatty Acids —not all carbons are
bonded to four other atoms (HAS DOUBLE BONDS)

http://www.biology.lsu.edu/introbio/Link2/fatty%20acids.gif
CLASSES OF LIPIDS

Triglycerides (fats) —three molecules of fatty acid
joined to one molecule of glycerol.
Saturated triglycerides —the 3 fatty acids are
saturated: hard at room temp: found in butter and red
meat: “bad fats”
 Unsaturated triglycerides —the 3 fatty acids are
unsaturated: soft at room temp: found in plant seeds:
“good fats”


Phospholipids —two fatty acids joined to glycerol.
They also have a phosphate group.

Important part of all cell membranes
Waxes —fatty acid chain joined to an alcohol chain:
waterproof: form protective layers in plants and
animals
 Steroids —four fused carbon rings with a functional
group: include many hormones and cholesterol

NUCLEIC ACIDS
Composed of C, H, O, N, and P
 Make up 4% of a cell
 Consists of repeating monomers called nucleotides


Each nucleotide has a phosphate group, a 5-carbon sugar
and a nitrogen base
Important in the transfer of information in the cell
 Types:

DNA —Deoxyribonucleic acid: determines the
characteristics of an organism and directs cell activities
 RNA —Ribonucleic acid: transfers information from
DNA to ribosomes: helps manufacture proteins: can act as
enzymes

Nucleotide
DNA Strand