The Chemistry of Life
• The FIVE primary elements of Life and
all Living things(You must know these symbols and the
corresponding names)
• C carbon
• H hydrogen
• O oxygen
• N nitrogen
• P phosphorus
• When elements are combined to
make molecules and compounds, the
subscript number represents how
many atoms of each element is in the
molecule.
• For example, water H2O is really 2
hydrogen and 1 oxygen atoms.
• are those that contain both
carbon (C) and hydrogen (H).
C6H12O6 and
methane, CH4.
Like glucose,
• are those that DO NOT contain
both carbon (C) and hydrogen
(H).
Like water
H2O and carbon
dioxide CO2 .
• O2
• C6H12O6
• CO2
• O2 OXYGEN
• CO2 CARBON DIOXIDE
• H2O WATER
Processes we have seen these in:
• photosynthesis
• Cellular respiration
• Carbon, water, & oxygen cycles
• Greenhouse gases (CO2 & H2O)
Macro mean BIG, sooooo…these are
mostly very big molecules, they are as
follows:
1. Carbohydrates
2. Lipids
3. Nucleic Acids
4. Proteins
H2 O
• Water covers most of the planet (74%
fresh and salt) and makes up the
greatest percentage of ALL living
organisms.
• Depending on temperature and
volume, humans can live WITHOUT
WATER for only one to ten days
The water molecule is POLAR:
• Meaning it has an uneven distribution
of charges, a slightly positive end and a
slightly negative end
• NONPOLAR molecules have an even
distribution of charges like petroleum
Remember like dissolves like, soooooo
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
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Because water is so important there are
two important watery terms you need to
knowHydrophilic –water loving molecules, will
easily dissolve in water
Hydrophobic -water fearing molecules,
do not mix/dissolve in water and often
move AWAY from water
• Hydrogen bonds are formed between
polar molecules involving slightly positive
Hydrogen and slightly negative Oxygen
or Nitrogen atoms
• They DO NOT change the molecules
involved, they are weak, temporary bonds
that are essential in ALL living organisms
• Surface tension is explained by the hydrogen
bonds formed by water molecules at the surface
• Cohesion-is the property where same
molecules are attracted to each other
• Adhesion-is the property where different
molecules are attracted to each other
A
monomer is a simple compound
that can join together to for polymers

A polymer is a large molecule
(macromolecule) composed of
repeating structural units connected
by covalent chemical bonds
Are made up of the elements C H O
 Are used as a source of energy
 Are important to many organisms for
structure and cell markers
 The monomers of carbohydrates are

called monosaccharides
 The polymers of carbohydrates are
called polysaccharides
Cell walls,
cell
Markers &
Cell
Energy
Glucose &
Glycogen
4
kcal (dietary calories) per gram
 Foods include bread, pasta, veggies
and fruit
 Glucose
 Fructose
 Ribose
 Deoxyribose
 Galactose
Starch
 Glycogen
 Cellulose
 Amylose
Disaccharides (made of only 2 monomers)
 sucrose
 lactose
 maltose

Many carbs end in the suffix -ose
Are made up of the elements C H O
 Are used as a source of stored
energy
 Are important to all organisms for as
the main part of ALL cell membranes

9
kcal (dietary calories) per gram
 Foods include butter, oil and animal fat

Saturated fats/lipids contain only single
bonds between carbons

Unsaturated fats/lipids have some
double bonds and fewer hydrogens

A triglyceride is made up of 3 fatty
acids and one glycerol molecule
Fatty acids
triglyceride
Steroids (hormones)
phospholipid
Lipids include many hormones including
steroids like testosterone, waxes like ear
wax, oils and blubber, and ALL cell
membranes like phospholipids
 Most of these are large nonpolar or
hydrophobic molecules.
 This means that they do not, usually, mix
with water.

Made up of the elements C H O N P
 Are important to all organisms for the
genetic code to make proteins
 The monomers are nucleotides
 The three parts of the monomer are a
nitrogen base, phosphate group and a
pentose sugar
 The polymers are DNA, messenger
RNA, ribosomal RNA and transfer RNA

Monomers
(Nucleotides)
4 for DNA
4 for RNA

Made up of the elements C H O N
 Function in movement because they
make up muscle and connective tissue
 Are important to all organisms for
structure and metabolic processes
 The monomers of proteins are amino
acids and there are 20 biologically
essential amino acids.

A protein’s shape is determined by the
arrangement of amino acids
 DNA is the instructions for making proteins
in organisms, a mutation means that the
protein may not work!
 The ending(s) is used for many proteins are
–in and –ase (enzymes)
 Small proteins are often called
polypeptides

4 kcal (dietary calories) per gram
 Foods include egg whites and animals,
plants contain limited amounts of protein


Amino acids
neg
pos

Enzymes regulate and maintain metabolic
functions in ALL living things. They are
essential to life
Enzymes
 Speed up reactions by lowering the energy
of activation
 Are biological Catalysts
 Are very specific
 Are reusable
 The
substrate is the specific thing
an enzyme works on
 The name of many enzymes ends
in –ase.
 Often are described as lock and
key because how very specific
they are and how they can be
reused like a lock
 The
active site is where the
substrate fits into the enzymes
 The product is what is produced
after the reaction
 Enzymes both build and break
down molecules in living
organisms
 Proteins,
so of course, enzymes are
very sensitive to any thing that can
change their shape, denature them.
 Temperature and pH can DENATURE
proteins so they do not work.
 Genetic defects, changes in DNA,
can produce proteins that do not
work.
The pH Scale is used to determine the
acidity and alkalinity (base)
 pH Scale ranges from 0 to 14

 pH
is the concentration of H ions
 Acid = pH below 7, The lower the
pH, the stronger the acid as pH
approaches 0
 Neutral = pH of 7pure water
 Base = pH above 7 (alkaline), the
stronger the base is as pH
approaches 14
http://www.lewport.com/10712041113402793/lib/1071204111340
2793/Animations/Enzyme_activity.html
 Hydrolysis-is
the breaking down of
molecules through the use of water.
For every bond broken, one water
molecule is used.
 Dehydration synthesis (AKA
condensation reaction)- is the
building of macromolecules by the
LOSS of a water molecule for every
bond built.

http://nhscience.lonestar.edu/biol/de
hydrat/dehydrat.html