Bio notes Essay

This essay has a total of 1005 words and 4 pages.

bio notes

REVIEW UNIT 1-THE CELL LIFE *There is no def. for life *Life can be characterized by a
list of things that we might agree living thing have in common-organized and contain
complex chemical substances, Made up of one or more cells, Use Energy, Have a definite
form& Limited size, Have a limited life Span, Grow, Respond to changes in the environment,
Reproduce, Evolve over time.*Metabolism is all the chemical reaction occuring in the cell
of an organism*All Living things must carry out processes to maitain life and homeostasis-
Nutrition, Transport, Respiration, Synthesis and Assimilation, Growth, Excretion,
Regulation, Reproduction, Metabolism.CHEMISTRY BASICS *Atoms of the elements are the basic
unit of mattter and are composed of protons, neutrons and electrons.*Atomic mass is the
sum of the number of protons and nuetrons in an atom.*The number of protons and electrons
is the same as the atomic number.*Isotopes of an element differ in the number of
nuetrons,*The outer most electrons of an atom are called valence electrons and are evolved
in chemical bonding.*Covalent bonds between elements involve the sharing of a pair of
electrons. *Transferring an electron betwwen atoms and then the pos. and neg. charged
atoms bonding together by charge forms ionic bonds. *2 adjacent molecules sharing
ahydrogen atom forms hydrogen bonds*A chemical formula indicates the type and number of
elements in a molecule.* A structural formula indicates the type, number, and bonding
between elements in a molecule.*Chemical reaction are composed of reactants and products
and the number of atom of elements of the reactants must equal the # of elements in the
products, i.e. Chemical equations must be balanced in the number of elements.* Mixure are
composed of different substances that are not chemically bonded,*Mixures where substances
are mixed but exist as individual molecules are called solutions. TRhe subst. making up
the bulk of the mixure is called the solevent and the other material(s) is called the
solute(s).* A liquid mixure where the material tends to stay is called suspension. ver
time the suspended materials do settle.*A colloidal dispertion is liquid mixure where the
suspended material particals are bigger than molecules,but do not ever settle.*pH is a
measure of hydrog ion concent. the larger the pH number the lower the hydro bond
concentration. Each whole pH indicates a 10 change in pH.*Bases have a pH betwwen 7 and 14
and acids have a pH below 7.BIOLOGICAL CHEMISTRY*All organic compounds contain carbon.
Only a few compounds containing carbon are not organic such as carbon dioxide.*Carbon's 4
valence electron and ability to for 4 covalent bonds allows it to be the basic chemical
element for life.* water is an essencial component ot life due to the chemical props of
water: *Polar molecule due to strong electron attraction of oxygen. *Polar nature of water
makes it a good solvent and ion conductors.*Has a high capac. to hold heat.*Water has high
adhesion and is cohesive to many other substances which acause capillary action.*Molecules
have groups of atoms that have a particular chemical func. and are called func. groups.
Important func. gruops in organic molecules includ: Hydroxyl or alcohol(-OH), carboxyl or
acid(-COOH), amine or base(-NH2)*Carbohydrates are complex compounds composed are carbon,
hydrog and oxy having both a food(energy) and stuctural role in life as well as a
component of other molecules.*simplist form carbohydrate are reconized because they
contain twice as many hydrogens and oxygens.*Carbohydrated form polymers by dehydration
systhesis of monosaccharides. Starch is a Polymer of glucose.*Carbohydrate polymers can be
broken down into monosaccharidesby hydrolysis. Specific enzymes in organisms catalyze this
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