Chemical Basis of Life
I.
How Matter is Organized
A.
Chemistry is the science of the structure and interactions of matter.
1.
All living things are made up of ______________ and ___________.
2.
Matter is anything that _______________ and _________________. a.
b.
Mass is the amount of ______________________________.
Weight is the ________________________________________. i.
E.g. in outer space, weight is close to zero, but mass remains the same as on Earth.
II.
Chemical Elements
A.
__________________ are substances that cannot be __________________
_________________ by ordinary means.
B.
116 elements (92 occur naturally)
1.
26 of naturally occurring elements are in the body
2.
Elements are grouped in the periodic table according to their characteristics and are represented by chemical symbols.
3.
Four most common elements that form 96 % of the body’s mass are… _______
_________ _________ and
________
III.
Structure of Atoms
A.
Atoms are the smallest units of matter that retain the
B.
properties of an element
Atoms consist of 3 types of subatomic particles
1.
Protons – have
__________, a _____________ charge and are found in the
_________________.
2.
Neutrons – have __________, _____ charge and are found in the ___________.
3.
Electrons – have ______________, ____________ charge and
____________ the nucleus in a ________________ pattern.
IV.
Periodic Table
A.
Atomic number is the same as the # of _______________ in an element.
If you add or remove protons you get a ___________________________.
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B.
Atoms are electronically neutron, so the # of __________________ (e-) is equal to the # of _____________________ (or the atomic number). If you add or remove electrons you get ___________.
C.
To determine the # of neutrons take the element’s ___________________ and subtract its’ _______________________ or number of ___________.
If you add or remove neutrons you get ___________________.
 Why is the atomic mass for many elements not a whole number?
 You don’t need to draw this picture of the periodic table, but you should know how to use a periodic table to determine the name (any of the first 20 elements), # of proton, # of neutrons, # of electrons, the # of rings for any element. You should also be able to tell me the relationship
between the different elements in each respective column.
V.
Chemical Bonds
A.
Bonds hold together the atoms in molecules and compounds
B.
An atom with a full outer electron shell is stable and unlikely to form a bond with another atom
C.
1.
The driving force in many chemical reactions is the need to fill in its ____________ or ____________________ ring.
Ionic Bonds
1.
When an Atom _____________ or _____________ one or more electrons
2.
In the body, ionic bonds are found mainly in ______________ and ______________

3.
Ionic compounds generally exist as _______________
4.
______________________ are ionic compounds that have dissociated in water into + and - ions.
D.
E.
Covalent Bonds-
1.
When two or more atoms __________________________ a covalent bond is formed and it is represented in structural drawings as a ________ between two atoms.
2.
Electrons spend most of the time between the 2 atomic nuclei a.
single bond = share 1pair (1 line) b.
double bone = share 2 pair (2 lines) c.
triple bond = share 3 pair (3 lines)
3.
Polar covalent bonds share electrons unequally between the atoms involved; e.g. water
Hydrogen Bonds
1.
Force of attraction between
________________ and other negatively charged ions, compounds or molecules.
2.
Only about ______% as strong as covalent bonds
3.
Large 3-D molecules are often held together by a large number of hydrogen bonds.
VI.
Chemical Reactions
A.
Occur when new bonds form or old bonds are broken.
B.
C.
Metabolism is the sum total of all the chemical reactions in the body
Types of Chemical Reactions

1.
__________________: Two or more atoms, ions or molecules combine to form new & larger molecules. a.
All synthesis reactions in the body together are called
_______________________.
2.
_______________________: large molecules are split into smaller atoms, ions or molecules. a.
All decomposition reactions occurring together in the body are know as ________________________.
3.
___________________: Substances exchange atoms a.
E.g. HCl + NaHCO
3
gives rise to H
2
CO
3
+ NaCl.
4.
__________________: Reactants can become products or products can revert to the original reactants. a.
H
2
O <=> H + + OH -
VII.
Water
A.
Most important inorganic compound in living systems
B.
___________________ Solvent
1.
Due to ________________ covalent bonds (hydrophilic versus hydrophobic)
2.
Its shape allows each water molecule to interact with 4 or more neighboring ions/molecules
C.
Heat Capacity of Water
1.
Heat capacity is ___________, therefore… a.
Can _______________ a large amount of heat with only a small increase in its own ______________________ b.
Due to the large number of hydrogen bonds in water

c.
Bonds are broken as ________________________ instead of increasing temperature of water d.
Large amount of water in body helps ________________ the impact of environmental changes in _____________________
2.
Heat of _________________________ is also high, therefore… a.
Amount of heat needed to change from liquid to gas b.
Evaporation of water from the __________ removes large amount of ______________
D.
Cohesion and adhesion creates high surface tension
1.
Difficult to break the ___________________________ if molecules are more attracted to each other than to surrounding air molecules
2.
Some respiratory problems are caused by water’s cohesive property.
 E.g. ______________________ allows water to collect in the air sacs of lungs, which makes it more difficult to inflate the lungs.
E.
Water is a good _________________
1.
Major component of lubricating fluids within the body a.
_______________ in respiratory and digestive systems b.
_____________________ fluid in joints c.
_____________________ fluids in chest and abdominal cavities d.
organs slide past one another
VIII.
Inorganic Acids, Bases & Salts
A.
Acids, bases and salts always dissociate into ions if they are dissolved in water
B.
1.
________________ increase the concentration of H+ in solution
2.
_______________ increase OH concentration or decrease H + concentration.
3.
________________ dissociate into anions and cations, none of which are either H+ or OH-
Acid & bases react in the body to form salts
1.
_______________________ are important salts in the body that carry electric current (in nerve or muscle)
IX.
Concept of pH
A.
pH scale runs from ___ to ______ (concentration of H+ in moles/liter)
1.
pH of _____ is neutral (distilled water -- concentration of OH- and
H+ are equal)
B.
2.
pH below 7 is _____________ and above 7 is ______________
Buffer Systems of the Body

1.
Body fluids vary in pH but the range of each is limited and is maintained by a variety of buffering systems. a.
gastric juice 1.2 to 3.0; saliva 6.35 to 6.85; bile 7.6 to 8.6 and blood 7.35 to 7.45
2.
Buffers convert _______________ acids to ____________ ones which contribute fewer H+ ions & have less effect on pH
3.
Carbonic acid - bicarbonate buffer system a.
together they contribute H+ or OH- ions as needed to keep the pH of the blood stable
HCl + ______________ —> ______________ + NaCl b.
Why not neutralize the strong acid with a strong base?
4.
What would your body do if it were exposed to a strong base like Draino (NaOH)? Write out equation!
I.
Organic Compounds
A.
Always contain _____________ and _________________
B.
Usually contain ____________________ bonds
C.
Usually large, unique molecules with complex functions
D.
Make up __________% of body mass
E.
Draw and explain the HONC rule?
II.
Functional Groups
A.
Hydrocarbons
1.
Composed of hydrogen and carbon and form the backbone of most organic molecules.
2.
Have a lot of stored ________________.
3.
Insoluble in water. Why?
4.
Examples: methane, propane, butane, octane etc.
B.
Alcohols (R-OH)
1.
A __________________ group.
 What does the “R” stand for?
2.
Soluble in water.

3.
Also good fuels.
4.
Examples: CH
3
CH
2
OH (Ethanol)
C.
Carboxylic Acid (R-COOH)
1.
Many are aromatic
 What does this mean?
2.
Water soluble
3.
Taste __________
D.
Amines (R- NH
2
)
1.
___________________ in water
2.
Alkaline or basic (a proton acceptor)
3.
Strong odors: Example: putresine and cadaverine and methylamine
III.
Carbohydrates
A.
Diverse group of substances formed from C, H, and O
1.
Ratio of one ______________ atom for each ___________ molecule
(carbohydrates means “watered carbon”)
2.
Glucose is 6 carbon atoms and 6 water molecules (H
2
0) = C
6
H
12
0
6
B.
Main function is source of ________________ for ATP formation
C.
Forms only 2-3 % of total body weight
1.
_________________ is storage in liver and muscle tissue
2.
Sugar building blocks of _________ & ________ (deoxyribose & ribose sugars)
D.
Only plants produce ________________ or cellulose for _______________
IV.
Diversity of Carbohydrates
A.
Monosaccharides
1.
Called simple sugars
2.
Contain 3 to 7 carbon atoms
3.
We can absorb only 3 simple sugars without further digestion in our small intestine: a.
Glucose found syrup or honey b.
Fructose found in fruit c.
Galactose found in dairy products
B.
Disaccharides (page 39)
1.
Composed of two sugar units

2.
How does a disaccharide form?
3.
This process is called dehydration synthesis or a condensation reaction.
4.
The opposite of dehydration synthesis is hydrolysis, when water is added to separate a bond.
C.
Polysaccharides
1.
Contain 10 or 100’s of monosaccharides joined by dehydration synthesis
2.
In animals glycogen is a chain of hundreds of glucose molecules found in liver & skeletal muscle.
3.
When blood sugar level drops, liver hydrolyzes glycogen to create and release glucose into the blood
V.
Lipids (fats)
A.
Formed from mainly C, and H, with little O
1.
Includes fats, phospholipids, steroids, eicosanoids, lipoproteins and some vitamins
B.
18-25% of body weight
C.
Hydrophobic: What does this mean? What about solubility
D.
Combines with proteins for transport in blood
1.
Lipoproteins (LDL and HDL)
E.
Triglycerides
1.
Neutral fats composed of a single glycerol molecule and 3 fatty acid molecules a.
Three-carbon glycerol molecule is the backbone b.
Fatty acids attached by dehydration synthesis
2.
Very concentrated form of energy a.
9 calories/gram compared to 4 for proteins & carbohydrates b.
Our bodies store triglycerides in fat cells if we eat extra food
3.
Saturation of Triglycerides a.
Determined by the number of single or double covalent bonds b.
Saturated fats contain single covalent bonds and are covered with hydrogen atoms----lard c.
Monounsaturated are not completely covered with hydrogen---safflower oil, corn oil d.
Polyunsaturated fats contain even less hydrogen atoms----olive and peanut oil

F.
Phospholipids
1.
Composition of phospholipid molecule a.
a polar head i.
A phosphate group (PO
4
-3 ) & glycerol molecule ii.
Can form hydrogen bonds with water b.
2 non-polar fatty acid tails i.
Interact only with lipids
2.
Major component of cell membranes a.
Double layer of phospholipids with tails in center
3.
Chemical Nature of Phospholipids
G.
Steroids
1.
Formed from 4 rings of carbon atoms joined together
2.
Common steroids a.
Sex hormones, bile salts, vitamins & cholesterol b.
Cholesterol found in animal cell membranes c.
Starting material for synthesis of other steroids
3.
Four Ring Structure of Steroids
VI.
Proteins
A.
12-18% of body weight
B.
Contain carbon, hydrogen, oxygen, and nitrogen

C.
Constructed from combinations of 20 amino acids.
D.
Dietary sources are meats, dairy and a few plants (legumes)
E.
Amino Acid Structure
1.
Central carbon atom
2.
Amino group (NH
2
)
3.
Carboxyl group (COOH)
4.
Side chains (R groups) vary between amino acids
5.
Be able to identify “R” group for any given amino acid.
F.
Formation of a Dipeptide Bond
1.
Dipeptides formed from 2 amino acids joined (dehydration synthesis) by a covalent bond called a peptide bond
2.
Polypeptides chains formed from 10 to 2000 amino acids.
G.
Levels of Structural Organization
1.
Primary is unique sequence of amino acids
2.
Secondary is alpha helix or pleated sheet folding
3.
Tertiary is 3-dimensional shape of polypeptide chain
4.
Quaternary is relationship of multiple polypeptide chains

H.
Protein Denaturation
1.
Function of a protein depends on its ability to recognize and bind to some other molecule
2.
Hostile environments such as heat, acid or salts will change a proteins 3-D shape and destroy its ability to function a.
raw egg white when cooked is vastly different
VII.
Enzymes
A.
Enzymes are protein molecules that act as catalysts
B.
Enzymes usually end in suffix -ase and are named for the types of chemical reactions they catalyze
C.
Activation Energy
1.
Atoms, ions & molecules are continuously moving & colliding
2.
Activation energy is the collision energy needed to break bonds & begin a reaction
3.
Increases in concentration & temperature, increase the probability of 2 particles colliding
D.
Catalysts or Enzymes
1.
Normal body temperatures and concentrations are too low to cause chemical reactions to occur
2.
Catalysts speed up chemical reactions by lowering the activation energy needed to get it started
3.
Catalysts orient the colliding particles properly so that they touch at the spots that make the reaction happen

4.
Catalyst molecules are unchanged and can be used repeatedly to speed up similar reactions.
5.
Effectiveness of Catalysts a.
1000 known enzymes speed up metabolic reactions to 10 billion times that in beaker
E.
Galactosemia
1.
Inherited disorder in which baby lacks a digestive enzyme
2.
Galactose accumulates in the blood causing anorexia
3.
Treatment is elimination of milk from the diet
VIII.
DNA Structure
A.
Huge molecules containing C, H, O, N and phosphorus
B.
Each gene of our genetic material is a piece of DNA that controls the synthesis of a specific protein
C.
A molecule of DNA is a chain of nucleotides
D.
Nucleotide = nitrogenous base (A-G-T-C) + pentose sugar + phosphate group