Article:
Faster-than-Light Neutrinos???
Impossible! (?)
Also in this article: Hadrons and
leptons? Baryons and mesons? Fermions and bosons? Gluons,
quarks, photons? Yes, there's more than protons,
neutrons, and electrons going on in an atom.....
Atoms:
A
page about how they're built and
how they behave...
1.
Enzyme
Video clip....
2.
Video 2...
3.YouTube
Video...
4.
Animation(illustrates
specificity,
reusing, and denaturing)
Enzymes are
proteins. They allow a chemical
reaction to occur between atoms/molecules (they can either assist in
combining them or separating them). The
enzyme is not affected and is re-used over and over. Only ONEenzyme is made to do ONE type of reaction, though. For example: Lactase
is an enzyme that splits Lactose (a
disaccharide) into its two monosaccharides, galactose and glucose.
Some people lack this enzyme Lactase, therefore have trouble
digesting lactose. Watch
THIS to see it in motion...
4. Nucleic Acids (RNA and DNA) (studied in a later unit)
How
do the caloric values
of carbs, lipids, and proteins compare?
Look here...
"Food Inc." is a documentary about how our food is grown, harvested,
processed, and sold to us. It is much different than it was in
our grandparents' day. To some people, it is a disturbing
change. Below is an interview with the maker of the
documentary.
Ionic Bonding (giving/taking of valence electrons):
Hydrogen bonding:
When the positive hydrogen end of a molecule
binds with the negative end of some other molecule or atom...
(This is what makes individual water molecules stick together
like magnets.)
The pH scale, with common household items
Note: "Alkaline" means the same as "basic" or "base."
Notice on this chart how the OH- and H+ amounts are inversely
proportional.
These are monosaccharides. Notice, only one
carbon ring is present
(where the ring bends is a C, except where the
oxygen is).
Dicaccharides are two rings together:
Polysaccharides are huge
chains of rings. Examples:
Glycogen (animals) energy
storage
Chitin (insects, some fungi)
structure
Starch [amylose] (plants)
energy storage
Cellulose (plants) structure
that proteins,
carbohydrates, and fats have important functions within the human body:
·
Proteins
are involved in almost every function in
the human body. For example, they serve as the
basis for structures, transport substances, regulate processes,
speed up chemical reactions, and
control growth.
○ Proteins are more important as a
source of building blocks than as a source of energy.
Proteins can function as an energy
source only if there is a shortage of carbohydrates or lipids.
¨
When proteins are
consumed, the bonds that hold the amino acids together are broken
during the process of digestion so that individual amino acids
are absorbed into the
bloodstream through the walls of the intestines.
¨
The amino acids are
carried by the blood stream to cells throughout the body where they
cross into the cells through the cell membrane.
¨
Once inside the cell,
they are used as raw materials to make all of the proteins required by
the organism.
○ Because of their structures, proteins serve different functions. For example,
¨
Structural proteins are
used for support such as connective tissue and keratin that forms
hair and finger nails.
¨
Transport proteins
transport many substances throughout the body such as hemoglobin
which transports oxygen from the lungs to the other parts of the
body to be used by cells
in cellular respiration.
¨
Hormone proteins
coordinate body activities such as insulin which regulates the amount
of sugar in the blood.
¨
Contractile proteins
help control movement such as proteins in the muscles which help
control contraction.
¨
Enzymatic proteins
accelerate the speed of chemical reactions such as digestive enzymes
which break down food in the digestive tract.
·
Carbohydratesare important as an energy source for
all organisms and as a structural molecule in
many organisms.
○ Carbohydrates are a primary source of fuel for cellular
respiration.
○ Carbohydrates are also used to store energy for short periods
of time.
○ The carbon, hydrogen, and oxygen that compose carbohydrates
serve as raw materials for the
synthesis of other types of small organic molecules, such as
amino acids and fatty acids.
○ Some carbohydrates (such as cellulose) are used as structural
material in plants.
¨
For most animals, foods
that contain these carbohydrates are important as fiber which
stimulates the digestive system.
·
Fats (lipids)are important to organisms for energy
when carbohydrates are scarce since they are
the primary way to store energy.
○ Fats serve a variety of functions in humans, such as providing
long-term energy storage,
cushioning of vital organs, and insulation for the body.
○ Fats also serve as a major component of cell membranes and are
one of the raw materials
necessary for the production of some vitamins and hormones.
The energy stored in organic molecules
determines its
caloric value.
Proteins, carbohydrates, and fats/lipids are three organic molecules with
different structures and different caloric values based on those structures:
·
Proteinsare molecules composed of chains of
amino acids.
○ Amino acids are molecules
that are composed of carbon, hydrogen, oxygen, nitrogen, and
sometimes sulfur.
○ There are 20 amino acids
that chemically bond in various ways to make proteins. Twelve of
these amino acids are made in
the body; others must be consumed from foods such as nuts,
beans, or meat.
○ Although proteins are more
important as a source of building blocks, amino acids may be
used by the body as a source
of energy (through the process of cellular respiration), but first
they must be converted by the
body to carbohydrates. This process does not happen as long
as there is a carbohydrate or
lipid available.
○ As a source of energy,
proteins have the same caloric value per gram as carbohydrates.
·
Carbohydrates (sugars and starches) are
molecules composed of carbon, hydrogen, and oxygen.
○ The basic carbohydrates are simple sugars (
monosaccharides)
such as glucose. These simple
sugars can bond together to make larger,
complex carbohydrate molecules, for example starch
or cellulose.
○ Carbohydrates are important because they the
main source of energy for the cell.
¨
When carbohydrates are
synthesized during the process of photosynthesis, the plants or
other photosynthetic organisms use them as a
source of energy or they are stored in the
cells.
¨
When complex carbohydrates are
consumed, the process of digestion breaks the bonds
between the larger carbohydrate molecules so
that individual simple sugars can be
absorbed into the bloodstream through the
walls of the intestines.
*
The bloodstream carries the
simple sugars to cells throughout the body where they
cross into the cells through the cell
membrane.
*
Once inside the cells, simple
sugars are used as fuel in the process of cellular
respiration, releasing energy which is stored
as ATP.
○ The caloric value of carbohydrates is
dependent on the number of carbon-hydrogen bonds. If
an organism has a greater supply of
carbohydrates than needed for its energy requirements,
the extra energy is converted to fats and
stored by the body.
·
Lipids,
including
fats,
are organic
molecules composed of carbon, hydrogen, and oxygen.
○ Lipid molecules are made of two
component molecules (
glycerols
and
fatty acids)
so they are
structurally different from
carbohydrates. Fats/lipids have more carbon-hydrogen bonds than
carbohydrates.
○ Fats are important to organisms
for energy when carbohydrates are scarce, but when there is
no shortage of food, stored fat
accumulates.
¨
When fats are
consumed, the molecules are broken down during the process of digestion
so that individual glycerol and
fatty acid molecules are absorbed into the bloodstream
through the walls of the
intestines.
¨
The blood stream
carries the glycerol and fatty acid molecules to cells throughout the
body where the molecules cross
into the cells through the cell membrane.
¨
Once inside the
cell, glycerols and fatty acids are stored for later use or used as fuel for
cellular respiration if there are
no carbohydrates available.
¨
The process of
cellular respiration releases the energy that is held in the chemical bonds of
the glycerol and fatty acid
molecules.
·
Due to the
structure and number of the carbon-hydrogen bonds that hold the different types
of
molecules (proteins,
carbohydrates, or fats) together, fats contain more energy (ATP) per gram
than carbohydrates or proteins, which explains
why fats have a greater caloric value.
