Chemistry
I. Basic Chemistry
1. Matter – anything that occupies space and has mass
a. Mass – the amount of matter in the object, remains constant
b. Weight – the amount of gravitational pull on an object
c. States of Matter
i. Solid – definite shape and volume
ii. Liquid – definite volume and indefinite shape
iii. Gas – indefinite volume and indefinite shape
2. Energy – the capacity to do work
a. No mass, no volume
b. Kinetic – energy in action, movement
c. Potential – stored or inactive energy that has the potential to do work
d. Forms of energy
i. Chemical – stored in chemical bonds
ii. Electrical – movement of charged particles
iii. Mechanical – directly involved in moving matter
iv. Radiant – travel in waves, electromagnetic
3. Composition of matter
a. Elements – unique substances that cannot be broken down into simpler substances
i. 92 naturally occurring
ii. 24 important in living systems, Main – C,N,O,H
b. Atoms - smallest units of elements that show properties of that element
i. Nucleus – center of the atom
1. protons (positive) and neutrons (neutral)
ii. Orbitals – most probable region of greatest electron density
1. electrons (negative charge)
c. Identifying
i. Atomic number = the number of protons in nucleus
ii. Atomic mass = Number of protons plus neutrons
1. Isotope – same element with different number of neutrons
d. Radioisotopes
i. Heavier isotopes of some elements decompose spontaneously
ii. Radioactive decay
4. Matter combinations
a. Molecules
i. A combination of two or more atoms held together by chemical bonds
b. Compound
i. When two or more different kinds of atoms bind – form molecules of a
compound
c. Mixtures
i. Substances composed of two or more components physically intermixed
ii. Solutions – homogeneous mixture of two or more components
1. Solvent - substance present in the greatest amount, dissolving
medium
2. Solute – substance present in smaller amounts
iii. Colloids – heterogeneous mixture that usually appears milky or
translucent
iv. Suspensions – heterogeneous mixtures with large, visible solutes that may
tend to settle out
d. How mixtures differ from compounds
i. There are no chemical bonds between components of mixture
ii. The properties of atoms and molecules are not changed
iii. The substances that make up a mixture can be separated physically
5. Chemical bonding
a. Electron shells – regions of space around the nucleus where electrons form the
electron cloud, contains orbitals
i. Represent different energy levels
ii. Outer levels are more apt to bonding due to decreased attractions
b. Reactivity
i. determined by outer orbital
ii. need or gain eiii. gains e- ,negatively charged
iv. loses e-, positively charged
v. opposites attract
vi. Ionic bonds
c. Ionic bonds
i. Ions – electrically charged atoms
1. Anion – the atom that gains an electron, net negative charge
2. Cation – the atom that looses an electron, net positive charge
3. Anions and cations are formed when electrons transfer between
atoms
ii. Opposites attract forming ionic bonds
d. Covalent bonds
i. Electrons are not completely transferred from one atom to another
ii. Electrons are shared
1. Polar – electrically unbalanced, unequal electron sharing
2. Nonpolar – electrically balanced, equal electron sharing
6. Chemical reactions
a. Occurs whenever chemical bonds are formed, rearranged or broken
b. Chemical equations – demonstrates the reaction written in symbolic form
i. Reactants – the reacting substances
ii. Products – the result of the reaction
c. Reactions
i. Synthesis – (anabolic) combination of smaller atoms/molecules A+B=AB
ii. Decomposition – (catabolic) a molecule is broken down into smaller parts
AB=A+B
iii. Exchange – combined synthesis and decomposition, parts of the reactant
molecules change partners AB+C = AC+B
iv. Oxidation-Reduction – both decomposition and exchange reactions
1. the reactant losing the electron is the electron donor – oxidized
2. the reactant gaining the electron is the electron acceptor – reduced
3. C6H12O6 + 6O2 = 6CO2 + 6H2O + ATP
v. Dehydration
1. To join or remove water
vi. Hydrolysis
1. To combine and add water
d. Factors that influence reactions
i. Temperature – Increasing temp. increases KE, increases rate of reaction
ii. Particle size – smaller particles move faster than larger (at the same temp),
higher tendency to collide, more collisions, the faster the reaction
iii. Concentration – higher concentrations cause faster reactions
iv. Catalysts – substances that increase the rate of chemical reaction without
themselves becoming chemically changed or part of the product
1. Enzymes – biological catalysts
II. Biochemistry
1. Inorganic – without carbon, nonliving
a. Water – the most abundant and important inorganic substance in living material
i. High heat capacity – absorbs and releases large amounts of heat before it
changes itself, controls body temperature by dispersing the heat through
the body
ii. High heat of vaporization – when water evaporates it requires large
amounts of heat
1. heat is pulled from the body and therefore cooled
iii. Polarity/solvent properties – universal solvent
1. biological chemicals depend on water to react chemically
iv. Reactivity – important reactant in many hydrolysis and dehydration
reactions
v. Cushioning – protects several body organs from physical trauma
b. Salts – inorganic solid containing cations other than H+ and anions other than
OH- which disassociates into ions
i. All ions are electrolytes – conduct electric current in solution
c. Acids – a substance that releases hydrogen ions
i. Proton donors
d. Bases – substance that accepts hydrogen ions
i. Proton acceptors
e. pH – the relative concentration of hydrogen ions in various body fluids
i. scale runs from 0-14
ii. Neutral – 7
iii. Above 7 – alkaline
iv. Below 7 – acidic
v. Neutralization reaction – the combining of H+ and OH- to form water and
neutralize the solution
f. Buffers – resist abrupt and large swings in the pH of the body fluids by releasing
hydrogen ions when pH begins to rise and by binding hydrogen ions when the pH
drops
2. Organic Molecules - Living compounds, all contain carbon
a. Carbohydrates
i. C, H, O – 1:2:1 ration at formation
ii. Classified based on size and solubility
a. Monosaccharides – single chain
a. Fructose, glucose, galactose
b. Disaccharides – double chain
a. Sucrose, lactose, maltose
c. Polysaccharides – multiple chain ( 3+)
a. Large, insoluble molecules that are great for storage
b. Starch – formed by plants, must be digested to glucose before use
by the body
i. Cellulose can not be digested
c. Glycogen – storage carbohydrate found in animal tissue
iii. Functions – cellular fuel
a. when not needed for fuel, is converted to glycogen or fat and stored
b. small amounts may be used for structural processes
b. Lipids - Insoluble in water
a. Neutral fats – fats when solids, oils when liquids
i. Made of a glycerol molecule and 3 fatty acids
1. the glycerol stays the same, the fatty acids may change
ii. Also called triglycerides
iii. Most concentrated source of usable energy
iv. Deposits are usually found beneath the skin to insulate the deeper
body tissues
v. Saturated – fatty acid chains with only single covalent bonds
between carbon atoms
vi. Unsaturated – one or more double bonds between carbon atoms
b. Phospholipids – modified triglycerides with a phosphorus-containing
group
i. Found in cell membranes
c. Steroids – flat molecules formed by 4 interlocking rings
i. Cholesterol – ingest & produce ourselves
1. essential for life – cell membranes, vitamin D, steroid
hormones, bile salts
c. Proteins – basic structural material of the body
a. Functional groups - Amine group, carboxyl group
b. Proteins are long chains of amino acids and bonded with peptide bonds
c. Enzymes – biological catalysts – alter the rate of reactions
d. Hemoglobin of the blood
e. Contractile proteins of the muscle
f. There are 20 amino acids, 50 combined form a protein
g. Structures
i. Primary – linear sequence of amino acids
ii. Secondary – the linear structure twist/fold on themselves, alpha
helix looks like a slinky, beta pleated sheet are linked side by side
iii. Tertiary – alpha or beta structures fold upon themselves and
produce a ball
iv. Quaternary – two or more polypeptide chains are arranged
h. Fibrous (structural) – extended strand-like appearance
i. Insoluble in water, stable – provide mechanical support and tensile
strength in body tissues – Collagen
i. Globular (functional) – compact, spherical
i. Soluble in water, mobile, chemically active molecules
ii. Antibodies, hormones, enzymes,
j. Protein Denaturation
i. If temperature or pH change too much, proteins begin to unfold
and loose their structure/shape
ii. Most can be reversed, but there is a point of no return – irreversible
damage
k. Enzymes – biological catalysts - regulate and accelerate the rate of
biochemical reactions
i. Can not force reactions to happen
ii. Highly specific – controls only a single reaction or a small group
of related reactions
iii. Some enzymes may need activated before they can function
1. certain amount of energy to “prime” the reaction
2. activation energy pushes the reactants to an energy level
where their random collisions are forceful enough to ensure
interaction
3. Increase temp. – too high will denature proteins
d. Nucleic Acids
a. DNA, RNA
b. Made of nucleotides – nitrogen base, pentose sugar, phosphate group
c. Nitrogen bases – adenine, guanine, cytosine, thymine, uracil
d. Control genetic material needed for cell division
i. Replicates material before the cell divides, provides instructions
for building every protein in the body
e. ladder shaped – sides are alternating ribose sugar & phosphate group
i. rungs are nucleotides, held together by hydrogen bonds
ii. complementary bases – A:T, G:C
f. Double helix shape