What Are We Made of? Pg. 265-266


Atoms are the building blocks of matter; cells are the building blocks of
life. Atoms make up molecules, and molecules make up cells!
There are four types of atoms, specific elements that are most commonly
present in living things. The elements are oxygen, carbon, hydrogen and
nitrogen. (CHON)
Carbon Atoms are Essential to Life and Proteins and Amino Acids Pg. 267-271






When molecules are built with rings or chains of carbon atoms, they are
called carbon based, or organic molecules.
Four basic organic molecules are found in all living things; carbohydrates,
lipids, proteins, and nucleic acids.
Carbohydrates are built from C, H, and O. Carbohydrates produce and
store energy. Simple carbohydrates like glucose are considered simple
carbohydrates. They can be joined into much larger molecules, complex
carbohydrates, like starch or cellulose. Cellulose is a structure found in
plat cells that add rigidity or structure. They are formed differently that
starch; humans can digest starch, not cellulose. This is why we do not eat
wood or paper for food!
Lipids are fats and also built from C, H, and O.. Lipids provide long term
energy storage AND lipids make up cell membranes. (Look at 2nd column
pg. 268 full 2 paragraphs.)
Proteins are made of amino acids. The molecules include all of CHON.
Some amino acids must be obtained through diet-they are considered
essential because they are obtained through diet. If you do not eat them
your body will “eat itself” by breaking down muscle for amino acids!
Proteins are the structural components of cells, and combine with lipids to
make membranes. They are also messengers, but most importantly assist
in cell reactions.
Nucleic Acids (made of CHON+) carry out instructions for cells and
store hereditary information in cells. There are two main types: DNA and
RNA.
A Closer Look at Cells pg. 272-273





Some organisms are a single cell. They are called single celled or
unicellular. Examples are yeast, algae and bacteria.
Other organisms are multi-cellular; they include plants, animals
and fungi.
All cells can be divided into two groups: prokaryotes and
eukaryotes.
Prokaryotes do not have a membrane enclosing genetic material.
In eukaryotes genetic material is enclosed in a nucleus.
Eukaryotes also have other organelles prokaryotes do not.
Prokaryotes are usually single celled like bacteria. Eukaryotes can
be either.