Cellular Respiration, Oxidation/Reduction, and Glycolysis
Day 43 Double
Cellular Respiration can be divided into three metabolic processes that are,
glycolysis and fermentation, the Krebs cycle, and oxidative phosphorylation.
Each of these processes occurs in a different and specific region of the
cell. Glycolysis occurs in the cytosol. The Krebs cycle occurs in the matrix of the
mitochondria. Oxidative phosphorylation via the electron transport chain, occurs
in the mitochondrial membrane.
In glycolysis, the 6-carbon sugar glucose molecule, is broken down into two
molecules of a 3-carbon molecule called pyruvate. This change is accompanied
by 2 ATP molecules and 2 NADH molecules.
In the Krebs Cycle, the pyruvate molecules are transported into the
mitochondria, and loses carbon dioxide to form acetyl-CoA, a 2-carbon molecule.
When acetyl-CoA is oxidized to carbon dioxide in the Krebs cycle, chemical
energy is released, which is then transformed in the form of NADH, FADH2, and
ATP.
In oxidative phosphorylation, the electron transport chain allows the release of
the large amount of chemical energy stored in reduced NAD+ (NADH) and
reduced FAD (FADH2). The energy released is transformed into the form of
ATP.
NADH + H+ + 3 ADP + 3 Pi + 1/2 O2 → NAD+ + H2O + 3 ATP
FADH2 + 2 ADP + 2 Pi + 1/2 O2 → FAD+ + H2O + 2 ATP
Fermentation occurs when oxygen is not present. Therefore, the pyruvate is
metabolized. In fermentation, glycolysis makes it possible for ATP to be
continually produced in the absence of oxygen. By oxidizing the NADH produced
in glycolysis, fermentation regenerates NAD+, which can take part in glycolysis
once again to produce more ATP.
http://www.phschool.com/science/biology_place/biocoach/cellresp/overview.html
http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20101/bio%201
01%20lectures/cellular%20respiration/cellular.htm
http://www.youtube.com/watch?v=nGRDa_YXXQA
http://www.youtube.com/watch?v=AdtAu5JgOV0
Oxidation/Reduction
Redox (reduction-oxidation) reactions include all chemical reactions, in which
atoms have their oxidation state changed. This can be either a simple redox
process, such as the oxidation of carbon to yield carbon dioxide, or the reduction
of carbon by hydrogen to yield methane. Or a complex process, such as the
oxidation of glucose in the human body, through a series of complex electron
transfer processes. Oxidation is the loss of electrons or an increase in oxidation
state by a molecule, atom, or ion. Reduction is the gain of electrons or
a decrease in oxidation state by a molecule, atom, or ion.
There is small riddle that might help you to remember what oxidation is, and what
reduction is. "OIL RIG" = Oxidation Is Loss, Reduction Is Gain.
http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookenzym.html#Oxidatio
n
http://chemistry.about.com/od/imagesclipartstructures/ig/Science-Clipart/RedoxReaction-Example.htm
http://www.youtube.com/watch?v=e6Xxz-VBE6s
Glycolysis
Glycolysis is a sugar break; because glyco=sugar and lysis=break. ATP is used
in glycolysis, to break glucose into 2 molecules. It is used in cellular respiration,
located in the cytosol.
http://staff.jccc.net/pdecell/cellresp/simpleover.gif
http://www.youtube.com/watch?v=O5eMW4b29rg
1. Why is cellular respiration necessary?
2. Where does cellular respiration mostly take place?
3. What is fermentation?
4. What is oxidation, and what is reduction?
5. What is the process of glycolysis?
1. All cells use oxygen to convert raw food products into energy they can use for
health. In the process they make a bi-product which is carbon dioxide and waste
material. If there was no cellular respiration the cell would die, because they
would be lacking the oxygen needed for food conversion, and they would have
no means of getting rid of their waste products.
2. The mitochondria
3. An anaerobic (without oxygen) cellular process, in which organic foods are
converted into simpler compounds, and chemical energy (ATP) is produced.
4. Oxidation is losing of electrons, and reduction is the gaining of electrons.
5. Glycolysis is the process in which one glucose molecule is broken down to
form two molecules of pyruvate. The glycolysis process is a multistep metabolic
pathway that occurs in the cytosol.
Vocabulary
Cellular Respiration-- A series of metabolic processes that take place within
a cell, in which biochemical energy is harvested from organic substances, and
stored as energy carriers for use in energy-requiring activities of the cell.
Oxidation-- A chemical reaction in which there is a loss of electrons.
Reduction-- A chemical reaction in which there is a gain in electrons.
Glyco-- sugar
Lysis-- breaking
Glycolysis-- the process in which one glucose molecule is broken down to form
two molecules of pyruvate. It occurs in the cytosol.