bio-chemistry notes chp 2.1, 2.2. organization of matter matter is anything that has mass and...
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Bio-chemistry Notes
Chp 2.1, 2.2
Organization of matter Matter is anything that has mass and
volume Weight is not a factor. Why? Can be in various states: liquids, solids, gases
Matter is made up of one or more elements. There are over ninety elements occur naturally Over 110 elements have been identified
Atoms The building blocks of elements All atoms have the same structure as
the others but differ in the amounts of the materials
The nucleus of an atom Positively charged particles that are
called protons (p+) Particles with no charge called neutrons
(n0)
Atoms
The energy levels that surround the atom contain a third particle Electrons (e-) have a negative charge
and balance the protons. Energy levels can only hold so many
electrons 1st shell holds 2 electrons 2nd and 3rd shells can hold 8 electrons
each
Atom Models
Elements
Everything is made from elements Cannot be broken down any further
except to be called atoms 25 elements are essential for living
organisms Trace elements are those elements
that compose less than 0.01% of all the atoms inside that organism
Periodic Table
Interactions of matter
Chemical bonding relates to the interaction of atoms with other atoms
Two atoms of different elements join together to be called compounds
Three Types of Bonding
Covalent – sharing of electrons
Ionic – transfer of electrons
Hydrogen – inner-molecular force between molecules
Covalent Bond
Covalent Bond
Ionic Bond
Hydrogen Bond
Hydrogen Bond
Chemical reactions Matter is neither created nor destroyed in a chemical
reaction Some examples of reading chemical reactions:
CH4 + 2 O2 ------------> CO2 + 2 H2O
Molecules? Atoms? Balanced?
Chemical reactions occur when the condition are right (temperature, energy)
Chemical Reactions
Isotopes Although the numbers of electrons and
protons are equal in a balanced atom, however, they might contain a different number of neutrons.
As the number of neutrons becomes unbalanced compared to the number of protons the nucleus itself becomes unstable. As the nucleus breaks apart it gives off radiation. Radiation is used in medical procedures today
Mixtures and Solutions Mixtures are when you combine two things
together and no reaction will occur. ex: Sand and sugar mixed together will not
react A solution is when two substances are
mixed and do react with each other. ex: Kool-Aid and water, the substances react
together Solute is the dissolved material The solvent is the dissolving substance The more solute the high the concentration
Acids and bases Use of the pH scale is to
detect the amount of acid or base that a substances has.
The scale has numbers from 1 to 14. Above 7 is a base Below 7 is an acid 7 is neutral.
Acids have hydrogen ions (H+)Bases have hydroxide ions (OH-)