Chemistry of Life

Ability to do work

• ~Potential Energy!!
• ~The stored energy in an object or system because of its position or configuration
• Can be transferred
• ~Chemical
• ~ Stored Mechanical

• Motion!!
• ~The energy of a body or a system with respect to the motion of the body or the particles in the system~
• ~Can be transferred from one moving object to another ->Collisions

• ~Fundamental units of matter; pure substances
• ~96% if the body is made from 4 elements
• Carbon (C)
• Oxygen (O)
• Hydrogen(H)
• Nitrogen(N)

Building blocks of elements

• ~Protons (p+)
• ~Neutrons (n°)

• ~Electrons (e-)
• ↳Shells

• ~117 Elements are listed by symbol
• ~First 94 elements occur in nature
• ~Groups = Vertical (Stand up as a Group_
• ~Period = Horizontal

~equal to the number of electrons OR protons that the atom contains

• ~Sum of the protons AND neutrons
• ~atomic mass units

• *Atoms of an element that differ in the number of their neutrons -> Neutrons are found in the nucleus*
• ~All elements have isotopes
• ~Define by their mass number
• ↳total number of neutrons and protons in the nucleus (Carbon 12 = 6 protons and 6 neutrons; Carbon 14 = 6 protons and 8 neutrons)

~when atoms will spontaneously emit subatomic particle or energy (radiation) when their nucleus breaks down

• ~Electrons occupy energy levels called electron shells
• ~Electrons closest to the nucleus are most strongly attracted (first orbital)
• ~Each shell has distinct properties
•     -The number of electrons has an upper limit
•     -Shells closest to the nucleus fill first

• ~Atoms are stable (inert) when the outermost shell is complete
• ~How to fill the atoms shells.....
• Shell 1 can hold a maximum of 2 electrons
• Shell 2 can hold a maximum of 8 electrons
• Shell 3 can hold a maximum of 8 electrons

Atoms will gain, loose, or share electrons to complete their outermost orbitals and reach a stable state

• ~atoms are considered stable when their outermost orbital has 8 electrons
• ~The exception to this "rule of eights" is Shell 1 which can only hold 2 electrons

• ~bonding involves interactions between electrons in the outer most valence shell
• ~Full valence shells do not form bonds
• ~Valence electrons are the outermost electrons of an atom

• ~Valence shells are not full and are unstable
• ~They tend to gain, lose, or share electrons
•     - allow for bond formation which produces a stable valence

• ~Become more negative!!
• ↳ If around a negative person you will gain negativity!!

Loose Negativity!!

• *The ability to pull electrons away from other atoms
•    -Not the same as charge
• ~Depends on size and number of vacancies it has in outermost shell

~two or more atoms of the same elements combined chemically

~two or more atoms of different elements combined chemically

• ~intermingling of two or more substances
•    -liquid mixture is called a solution

• ~coupled (occur together, simultaneously) chemical reactions that occur when a transfer of electrons, hydrogen, or oxygen takes place
•      -trying to make stable

~Loss of electrons, hydrogen, or both, or the gain of oxygen-> oxygen = chemically negative

• ~Gain of electrons, hydrogen, or both or the loss of oxygen
• ~The accumulation and transfer of electrons is essential to the synthesis of new energy-storage molecules such as ATP
• ~Electron accumulation builds reducing power while electron transfer releases energy in small, manageable amounts

• ~Result from the loss or gain of electrons
• ~Charged particles

• Negative due to gain of electrons
•     -ex. Chloride

• Positive due to loss of electrons
• - Cats are "Pawsative"
• ex. Sodium

• A strong mutual attraction of oppositely charged ions
• ~Atoms become stable through the transfer of electrons
• ~Form when electrons are completely transferred from one atom to another

• ~Covalent bonds share
• ~Atoms become stable through shared electrons -> Shared in pairs
• ~Single covalent bonds share one pair of electrons
• ~Double covalent bonds share two pairs of electrons

• *Equal!
• ~Electrons are equally shared between the atoms of the molecule
• ~Electrically neutral as a molecule

• *Not Equal!
• ~Electrons are not shared equally between the atoms of the molecule
• ~Have a positive and negative side or "pole"

• ~Weak chemical bonds
• ~Hydrogen is attracted to the negative portion of polar molecules
• ~Provides attraction between molecules

• ~High heat capacity
• ~High heat of vaporization
• ~Universal solvent
• ~Molecules are cohesive and adhesive
• ~High surface tension
• ~Frozen water is less dense that liquid water

• Water = universal solvent
• ~Water is able to dissolve a large variety of substances, due to the polarity
• ~Most of the molecules in cells are also polar and so can form hydrogen bonds, or ionic bonds with water

• ~Solutes that have an affinity (attraction) for water and dissolve in it easily
•    ~Generally polar molecules or ions
•    ~many small molecules -> sugars, organic acids, some amino acids

• Molecules not easily soluble in water ->stay away from water
•    -Lipids, protein and generally nonpolar molecules

• ~Unequal distribution of electrons gives water its polarity
• ~The water molecule is bent rather that linear
• ~The oxygen atom at one end of the molecule is highly electronegative drawing the electrons toward it
• ~This results in a partial negative charge at this end of the molecule, and a partial positive charge around the hydrogen atoms

• Because of their polarity
•    -water molecules are attracted to each other
•    -orient so the electronegative oxygen of one molecule is associated with the electropositive hydrogens of nearby molecules
•    - Hydrogen bonds are about 1/10 as strong as covalent bonds

~The result of the collective strength of vast numbers of hydrogen bonds

Water is characterized by an extensive network of hydrogen bonded molecules which make it cohesive

Resist separating from each other