Biochemistry:
Chemistry Part 2
The Organic Molecules
Biochemistry Preview/Review
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90 naturally occurring elements on Earth’s crust
11 are common to living organisms
20 found in trace amounts
4 elements make up approximately 96.3% of the
total weight of the human body:
 nitrogen
 carbon
 oxygen
 hydrogen
In varying combinations and amounts, these four
elements make up mostly all of the compounds
found in living things
Elements by Mass in the
Human Body
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Oxygen: 65%
Carbon: 18.5%
Hydrogen 9.5%
Nitrogen: 3.3%
Phosphorus: 1.0%
Sulfur 0.3%
Sodium: 0.2%
Magnesium: 0.1%
Silicon: trace
Fluorine: trace
C.H.N.O.P.
What is polymerization?
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The formation of
larger compounds
from smaller
compounds
The bonding process
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Polymers formed from monomers via
dehydration synthesis
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Where water is removed from the two
joined molecules
Separated via hydrolysis
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Where water is put back in place
Dehydration Synthesis
A + B + C = ABC + 2 molecules of H2O
H2O
H2O
Hydrolysis
In order to reverse the previous reaction
(dehydration synthesis), we need to add
water to the product ‘ABC’.
So:
ABC + 2 molecules of H2O = A + B + C
Example of a
Modular Home
(i.e.,
Macromolecule)
Living Room
Bed
Room
Monomers
Monomers
Kitchen
Bathroom
All of the individual monomers form the single polymer
What is “Biochemistry”?
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Common Sense: Chemistry of Life
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What does this mean?
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The foods you eat.
What those foods contain.
How they affect you based upon the chemical
reactions they cause.
So what do you eat….
So What’s In The Foods
You Eat?
Proteins
Fats (a.k.a.- Lipids)
Carbohydrates
So What Does
“Organic Mean”?
Organic v. Inorganic Compounds?
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Contain carbon to hydrogen (C-H) bonds
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Inorganic compounds = NO (C-H) bonds
“Bucky Ball”
Toughest College Class EVER!!!!
Organic Chemistry
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Definition: The chemistry of carbon and its 2
MILLION compounds!
Carbon: Strong & stable covalent bonds:
 4 valence electrons
Carbon forms bonds w/itself in forms of long chains
or rings called “carbon backbones”
 These “backbones” are the basis of all of your
foods and, since you are what you eat, what you are
made of!
 This includes Carbohydrates, Proteins, Lipids,
DNA
Compounds of Life: The
Macromolecules
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There are four groups of organic
macromolecules:
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Carbohydrates
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Sugars, Starches
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Fats, Waxes, Oils
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Amino acids
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RNA, DNA
Lipids
Proteins
Nucleic acids
Carbohydrates
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Commonly referred to as sugars and
starches
Energy stored in the bonds of the
carbohydrate molecule
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1 grams = 4 calories (Kilocalorie)
Bonds easily broken down (water) by the
body so “Carbs” are the body’s First
Choice of Energy!
Carbohydrates
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They consist of Carbon, Hydrogen and
Oxygen atoms in a consistent ratio of
1:2:1 or C1H2O1
The simplest unit/monomer:
monosaccharides
Monosaccharides
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Simple Sugars
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Some examples are glucose, galactose and
fructose
They all have the same chemical
formula, C6H12O6, but they have
different molecular structures
 Called
Isomers
Monosaccharide Isomers
Galactose- Milk Sugars
Glucose- Plant Sugars
O OH H OH OH OH
H
C
C
C
C
C
C
H OH H
H
H
H
H
O OH H
H OH OH
C
C
C
Fructose- Fruit Sugars
OH O
H
C
H
C
H OH OH OH
C
C
C
C
OH H
H
H
H
C
C
C
H OH OH H
H
H
Monosaccharide Isomers
Forming Carbohydrate
Polymers
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Two monosaccharides: glucose & fructose
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Form a disaccharide: Sucrose (Table Sugar)
Put table sugar in a pan and turn on the
heat…what happens?
Disaccharide formation
Glucose
Fructose
Sucrose
+
OH
C6H12O6
+
OH
O
C6H12O6
C12H22O11
Water formed from bond between two -OH structures
with an ‘O’, remaining at bond
H2O
Disaccharides
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Other disaccharides are:
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Maltose (malt sugars)
Lactose (milk sugars)
“Di-” & “Poly-” are “complex carbs”
“Mono-” are “simple sugars”
Reversing Disaccharide
formation with Hydrolysis
Sucrose
Glucose
+
Fructose
H2O
O
OH
C12H22O11
C6H12O6
Add Water to Reaction
OH
C6H12O6
Function of Polysaccharides
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Polysaccharides are many (3 or more)
monosaccharides joined together
This is the form of sugar that is stored
in living things
Storage forms of
Polysaccharides
•Glycogen is the animal form of stored
sugar
•It can be hundreds to thousands of
glucose molecules long
•Starch is the plant form of
stored sugar
•It can be hundreds to
thousands of glucose molecules
long
•It does not “branch” like
glycogen
•It also shows a distinctive “branching”
pattern
Starches continued
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Cellulose is a type of starch that plants synthesize
It is the principal component of wood, or the cell
walls of plants
The human appendix is believed to have been used to
break down cellulose tens of thousands of years ago
Humans, as a whole, can no longer break down
cellulose and so it is now considered fiber in our diets
Lipids
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Lipids include
 fats,
 oils
 waxes
**(Fats and waxes are solids at room temperature while oils are
not)
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Lipids have three main functions:
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Energy storage
Forming biological membranes (cell membranes)
Chemical messengers in the body
Lipids
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Energy Storage: Potential Energy
Lipids
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Biological Membranes: Cell Membranes
Lipids
Chemical
Messengers: i.e., Steroids
Lipids
Cholesterol…Good or Bad?
Polymerization of a Lipid
H
H
C
OH
H
C
OH
H
C
OH
H
OH
O
H H
C
C
H
H
H
H
H
C
C
C
C
C
H
H
H
H
H
Carboxyl
Glycerol
Fatty Acid
Chain
H
+ H2O
Saturated v. Unsaturated Fats
H H
H
H
H
H
C
C
C
C
C
C
H
H
H
H
H
H
LARD or CRISCO!
H H
H
H
H
Unsaturated Fats: Openings via Carbon to Carbon
double bonds
C
H
C
C
C
C
C
H
H
H
H
H
Saturated Fats: No openings; Hydrogen bonded to
every Carbon.
H
Strong, hard to break bonds.
Bonds now easier to metabolize.
CANOLA OIL, FISH OIL, ETC.
Proteins
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Proteins contain N, O, H and C
Proteins are made from long “chains” of amino
acids
Bonds between amino acids called peptide
bonds.
 Proteins also called polypeptides.
Amino acids have the same basic structure
with the exception of the “R” group: LEGO!
Amino Acid Uses
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Proteins used for building and
maintenance of tissues: i.e., muscle
Not natural
Natural
Amino Acid Uses
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Proteins (amino acid chains) are your last
resort as a food source because they are
difficult to metabolize
Amino Acid Structure
H
H
N
H
C
R
O
Carboxyl Group
C
OH
Carbon
Backbone w/”R”
group
Amino Group
Forming a Polypeptide through
Dehydration Synthesis
H
H
N
H
C
R
O
H
C
H
N
OH
H
H2O
C
R
O
C
OH
Forming a Polypeptide through
Dehydration Synthesis
H
H
N
H
C
R
O
C
H
H
N
C
R
O
+
C
H2O
OH
The result of taking water from the two amino
acids is a polymer, or protein, that has two
monomers connected at a Carbon and a Nitrogen
Nucleic Acids
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2 different nucleic acids:
 RNA-Ribonucleic acid
 DNA-Deoxyribonucleic acid
Both are composed of:
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Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorus
Nucleic Acids
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Monomers of nucleic acids are called
nucleotides
Nucleotides have three basic parts:
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A special 5-carbon sugar
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A phosphate group
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A nitrogenous base
Nucleic Acids
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The nitrogenous bases contain nitrogen
A nucleotide, depending upon DNA on RNA,
will have one of the following nitrogenous
bases:
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Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)
Uracil (U)
Diagram of a Nucleotide
Phosphate
Group
Nitrogenous
Base
5-Carbon
Sugar