The document summarizes key information about organic molecules and cell membranes. It states that organic molecules contain carbon and are made up of polymers like carbohydrates, lipids, proteins, and nucleic acids, which are composed of monomers. The cell membrane forms the boundary between intracellular and extracellular fluids using a phospholipid bilayer. It contains integral and peripheral proteins and transports molecules through channel and carrier proteins.

1. ORGANIC MOLECULES
Most of the molecules in living things are organic mole-
cules, meaning that they contain carbon. The fact that car-
WORK CITED bon has four electrons in its outermost shell means that it is
capable of covalently bonding with other atoms to fill its Artifact 2:
Inorganic molecules include water, oxygen and car- outermost shell. Organic molecules typically involve carbon
bon dioxide, as well as acids, bases and salts bonded to hydrogen, oxygen, nitrogen, and other carbon
atoms. (source 1)
Levels of
(electrolytes). These molecules are just as vital to life
as organic molecules because for example every
living being needs water to survive. While organic
Polymer: Monomer: Organization
compounds require carbon covalent bonds, inorganic Polysaccharide Monosaccharide
compounds do not. (source 1) Lipid Glycerol/Fatty Acid
Protein Amino Acids
Nucleic Acid Nucleotide
There are four major kinds of organic molecules: carbohy-
drates, lipids, proteins, and nucleic acids. Each of these
exists as a polymer, composed of monomers. (Source 1)
1. Thibodeau, Gary. Anthon'ys Textbook of
Monomers are joined together by dehydration synthesis
(condensation), which forms water molecules in the pro- Anatomy and Physiology. Seventeenth. St. Lou-
cess.
is, Missouri 63146: Mosby, 2003. Print.
Polymers can also be broken into monomers by hydrolysis
2. N.d. Photograph. n.p. Web. 17 Sep 2012.
reactions, which use water molecules in the process (source
1) <http://www.glogster.com/
heyheyhey12345678/organelles-of-cells/g-
6nhse2jnscand9i2bv7m0vt?
old_view=True>.
3. N.d. Photograph. n.p. Web. 18 Sep 2012.
<http://www.universetoday.com/wp-content/
uploads/2010/02/c-atom_e.gif>.
(Sourrce 4. N.d. Photograph. n.p. Web. 18 Sep 2012.
3)
<http://www.lenntech.com/water-chemistry-
faq.htm >.

2. Cell membrane
Cont. ALL ORGANELLES ON PAGE 69
Its function is to be the boundary between the extracel-
lular fluid and the intracellular fluid. There are also carrier proteins (not shown). Carriers Golgi Complex: modifies, packs, and distributes
are integral proteins that bind to specific molecules proteins.
It is made up of phospholipids; it is arranged into two and transport them to the other side of the membrane.
Mitochondria: Extracts Energy
layers called the phospholipid bi-layer. The hydropho- Membrane proteins are also important in activating
bic fatty acid tails are facing towards the inside of the second messenger systems. A messenger such as a Lysosomes: contains digestive enzymes.
membrane, while its hydrophilic polar heads are toward hormone or neurotransmitter binds to its receptor site.
Centrioles: Important in Mitosis
the exterior of the membrane. The receptor releases a G protein, which may bind to a
membrane-bound enzyme such as adenylatecyclase. Plasma Membrane: separates the fluids
There are two types of proteins that are important to the Adenylatecyclase converts ATP to cyclic AMP
Nucleus: Contains DNA
membrane: integral proteins and peripheral proteins. (cAMP). cAMP is the second messenger. cAMP acti-
vates a kinase, an enzyme that adds phosphate groups Ribosomes: Assemble Amino Acids (protein)
Carbohydrates, glycolipids, glycoproteins, and choles- to other cytosolic enzymes, thus activating some and Smooth Endoplasmic Reticulum: Stores calcium
terol are found in the membrane. deactivating others. This leads to an alteration in vari- in the bones.
A phospholipid consists of a polar portion, called the ous metabolic activities. (source 1)
Vesicles: carries lipids and proteins to cell sur-
head, and two longer fatty acids, called the tail. Thus a
face
phospholipid molecule is represented as a sphere with
two long projections. When mixed with water, the Rough Endoplasmic reticulum: studded with
heads are attracted to the polar water molecules. The ribosomes and functions in protein synthesis.
nonpolar tails move as far from water as possible, and a
Centrosomes: breaking of microtubules in the
double layer of phospholipids with tails to the interior
cell.
results.
Cytoplasm: internal substance that contains tiny
Functions: 1) They can provide receptor sites for chem- suspended structures
ical messengers such as hormones and neurotransmit-
Peroxisomes: Contains enzymes the detoxify
ters. 2) Enzymes catalyze reactions near the membrane.
harmful substances (source 1)
3) Channel proteins are constantly open to allow pas-
sage of various solutes all the time. 4) Gated channels
open and close to regulate the passage of various so-
lutes. 5) Motor molecules are proteins that pull mem-
brane proteins and cause cellular movement. They tend (source 2)
to be peripheral proteins. 6) Glycoproteins function in
cellular identification. 7) Cell adhesion molecules
(CAMs) bind one cell to another.