Material covered so far.
Atoms and molecules, bonding, biological atoms
CHONPS
CLASSES OF ORGANIC MOLECULES (P44)
You must know about 4 kinds of Organic Molecules, the ones most important to building and maintaining our bodies. They are
Carbohydrates, Lipids, Proteins, and Nucleic Acids (DNA and RNA)
THE FIRST CLASS OF ORGANIC MOLECULE IS THE CARBOHYDRATES
CARBOHYDRATES- C + H20 x n
Sugars can be mono- di- and poly- saccharides,
- good for fast energy, the main energy molecule is glucose, a monosaccharide or simple sugar. The sugars are stored
in your muscles as glycogen a form that is easiest to use.
-in animals, high levels of sugar in the blood cause the release of the hormone insulin (hormones are chemical
messengers). Insulin tells muscle, liver and fat cells to start pulling sugar out of your blood for storage as fat. Later,
when you need extra energy, the fat can be broken back down into the sugar your body needs for energy.
Starch is used by plants to store their extra sugar.
-Starches are long chains of glucose molecules bonded together. A typical starch molecule can have from 500 to
1000’s of glucose molecules bonded together as a long polymer chain.
Cellulose and fiber – give shape and strength to plant cells.
– Cellulose is another carbohydrate made from chains of sugar molecules. Some say it is the most common molecule
on earth because most plant cells, wood and most plant products are mainly cellulose.
Even though it is made from sugars, most animals cannot digest cellulose to get the energy they need. Those
that can usually have bacteria in their gut that break down the cellulose to a form they can use. (Sheep, cows,
horses, many insects)
THE SECOND CLASS OF ORGANIC MOLECULE ARE LIPIDS.
LIPIDS - three main kinds are Triglycerides, Steroids and Phospholipids.
Triglycerides = (p47) A glycerol with 3 fatty acid chains attached. The fatty acids are made of long chains of carbon
and hydrogen.
There are 3 kinds of triglyceride- Fats, oils, and waxes
Fats – Three main types of Triglyceride
Fats – their uses
-Fats are usually used by animals for long-term energy storage.
-Fats are also important in the brain and nervous system, they act as insulation, keeping the electricity from
leaking out.
-Fats are valuable for insulation in cold weather.
Oils - their uses
Oils are mostly used by plants for energy storage. They also can be used to give bad taste to plants for protection (or
good flavors like in mints).
Oils are also used by both animals and plants for waterproofing
Waxes – mostly used by plants for waterproofing and protection.
The second type of lipids are steroids.
Steroids - Are a type of hormone. There are many different kinds, but they are all lipids that are used to send
messages through the body telling it what to do. (for example anabolic steroids help in healing of muscle
injuries). Most Steroid hormones help control either the body’s growth and development, or help control sexual
cycles and impulses.
The third type of lipid are phospholipids
Phospholipids – are made from two long fatty acid chains attached to a phosphate group.
Their usesPhospholipids are the main part of the membranes that surround all cells and all organelles.
THE THIRD CLASS OF ORGANIC MOLECULE YOU MUST KNOW IS PROTEINS
Proteins are made of long chains of amino acids. Proteins are also called polypeptides. Proteins contain Nitrogen.
There are 22 different amino acids. The order that these amino acids are in, decide how the protein will
Amino Acids contain Nitrogen
work.
There are 3 main kinds of Protein – Structural Proteins, Enzymes, and Hormones.
Structural Proteins- Like the name, they give structure to body parts, either the whole thing, or as a
for other tissues to attach to.
skeleton
Some examples are the Keratins that help build hair, skin, nails and hooves, feathers, bird beaks
and other hard structures;
the proteins actin and myosin that muscles are the main ingredients of muscles; silk from spiders
and caterpillars; and collagen, which is important both in animal hides, and in the ligaments and
tendons that connect up muscles and bones.
Enzymes – Enzymes are proteins that help to speed up chemical reactions.
Some enzymes work according to the ‘lock and key’ model, or the ‘induced fit’ model - meaning that the
chemicals that they work with fit into the 3-D shape of the enzyme to make it easier for them to combine,
or to be broken apart.
The place where the substrate (the molecules that are reacting) fits into the enzyme is called an active site.
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Hormones- Some proteins act as hormones, or messengers,
within the body. They move in the
bloodstream and
cells and tissues that are sensitive to the hormones
will receive the message and go to work (or stop).
Examples of protein hormones are Human Growth
Hormone, Prolactin-which causes mammals to
produce milk, serotonin-which helps control your
mood, and many others.
THE FOURTH TYPE OF ORGANIC MOLECULE ARE THE NUCLEIC ACIDS – DNA AND RNA
Nucleic Acids – Nucleic acids are the organic molecules that store information for building our bodies, or that work to
copy, decode and build the molecules our cells need to survive.
Nucleic acids are made of chains of molecules called nucleotides that link together into huge molecules.
Please remember that these Nucleotides contain C, H, O AND P
DNA is an information Storage molecule. When DNA is read, each 3 units in the chain are read and
will stand for one amino
acid that is going to be part of
a protein.
RNA - has only 1 side of the ladder (is a single helix)(DNA has 2). RNA works to copy genes from the DNA and to
make the Proteins the gene codes for.
RNA works to read DNA, make a copy of the part that needs to be read(a gene), and then to help build the
protein that the gene on the DNA codes for.