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What substances on Earth cannot be broken down any further?
Water? Paper? Wood? Steel? People?
Gold? Iron?
Elements:
Substances that are made up of only one type of atom.
ex.
Gold (Symbol: Au) Silver (Ag) Sodium (Na) - are types of metals
Oxygen (O), Hydrogen (H), Helium (He), carbon (C) , Chlorine (Cl) Silicon
(Si), Sulfur (S)- are types of non-metals
Compounds:
substances made up of two or more elements combined in specific amounts.
ex: Sodium
Chloride-NaCl (formula for table salt)
one atom of sodium
for every one atom of chlorine
ex: Dihydrogen
Oxide-H2O (formula for water)
two hydrogen atoms
for every one oxygen atom.
The cell
is a complex "Chemical Factory" made up of the same elements
that show up over and over again in different ways. These elements can
also be found in the non-living environment. Of
all the elements found on earth, there are four main ones that are present
in the greatest percentages (amounts) in living things. They are:
C-
carbon
H-
hydrogen
O-
oxygen
N-
nitrogen
There
are other elements that are also found in living things, but in much smaller
quantities. These are:
S-sulfur,
I-Iodine, Na-sodium, Fe-iron, Ca-calcium, K-potassium,
Cl-chlorine,
P-phosphorus Mg-magnesium
ALL
organisms are made up of Inorganic and Organic compounds.
I.
Inorganic Compounds
* compounds that do not contain both carbon and hydrogen.
* organisms do require certain inorganic substances to survive:
A. Water (H2O)
* 65% of most living tissues is H2O!!!
* many substances in living things are dissolved in water (solution)
* water acts as a transport agent to move substances across cell membranes.
B. Salts (ex: NaCl-
sodium chloride)
* provide many necessary ions for body processes.
* help to regulate certain body processes.
C. Acids &
Bases
* help to regulate certain body processes
II. Organic
Compounds
* compounds that contain both carbon and hydrogen
* called organic because they are mainly found in living things

A. Carbohydrates-provide
energy for living things
B. Lipids-stored
energy, structural part of cell membranes
C. Proteins-necessary
for growth and repair of tissues, found in cell membranes, enzymes,
and other important functions.
D. Nucleic Acids
(DNA/RNA)-molecules of genetic code
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