Living Environment Translated Arabic 2014 | Page 34

2. General Notes
a. Atoms are made up of protons, neutrons, and electrons.
b. Elements are made up of only one kind of atom.
c. Basic Element symbols:
1. Carbon- C
2. Hydrogen- H
3. Oxygen- O
4. Nitrogen- N
5. Phosphorus- P
6. Sulfur- S
d. Compounds are made of two or more different kinds of atoms
which are chemically combined.
e. Mixtures are made of two or more different kinds of atoms
that are physically combined.
f. Formulas can be written for compounds but not for mixtures.
g. Organic compounds ALWAYS contain carbon and hydrogen and
are usually associated with living things.
h. Organic compounds :
1. Carbohydrates:
a. Made up of carbon, hydrogen and oxygen
b. Examples: sugars, starches, cellulose
c. Function: supply energy for cell processes, form plant
structures, short-term energy storage
2. Lipids ( Fats):
a. Made up of carbon, hydrogen, oxygen, and phosphorus
b. Examples: fats, oils, waxes, phospholipids, and
cholesterol
c. Function: store large amounts of energy long term,
form cell membranes