What is glycolysis?

Question

What is the citric acid cycle?
What is the electron transport chain?

can someone plz give me a simple two-sentence explanation of these processes? thank u!! (:

Answer 1

In brief:
A process in which glucose (sugar) is partially broken down by cells in enzyme reactions that do not need oxygen. Glycolysis is one method that cells use to produce energy. When glycolysis is linked with other enzyme reactions that use oxygen, more complete breakdown of glucose is possible and more energy is produced.

Answer 2

Glycolysis is the step-wise break down of Glucose into pyruvic acid. It yields a small amount of energy in the form of NADH. This is the fermentative part of metablolism that does not require oxygen.

The citric acid cycle is the process that stepwise breakdown of pyruvic acid to release CO2 and yields much more energy in the form of NADH. The NADH must be recycled and ultimately requires oxidation.

The electron transport chain is a series of membrane bound enzymes that convert energy from NADH to ATP. The chain catalyzes a series of oxidation steps - ultimately to convert O2 to H20. These steps are linked to pumping hydrogen ions (H+) and the hydrogen ion gradient is used to make ATP, the main energy currency of the cell.

Chech wikopedia or any Biochemistry textbook for illustrations of these processes.

Answer 3

These are the three main steps of aerobic respiration which breaks down glucose to get energy to make ATP.

Glycolysis breaks glucose into 2 molecules of pyruvate. In the process it has a net gain of 2 ATPs and some NADH2.

The citric acid cycle breaks the molecules down further, stripping off CO2 to get rid of it. The gain from the citric acid cycle is some more ATP as well as NADH2 and FADH2.

The electron transport chain makes the most ATP. It takes the electrons from NADH2 and FADH2 and passes them along to the final electron acceptor which is oxygen.

Answer 4

Maybe three!

Glycolysis is the breakdown of glucose, in the presence or absence of oxygen, to form 2ATP molecules, NADH2 and two molecules of Pyruvic acid.
The Citric Acid Cycle is a series of enzyme controlled reactions that occurs in the presence of oxygen and results in the formation of Carbon Dioxide, water and 36ATPs from the two pyruvic acid moecules obtained from glycolysis.
The electron transport chain is a system of hydrogen acceptors that produce ATP from ADP and Phosphate each time hydrogen atoms are passed from one to another, with oxygen being the final acceptor.

Answer 5

Glycolysis occurs in the cytoplasm in the absence of O2and involves the following:


1. Two molecules of ATP are use to phosphorylate glucose and start glycolysis

2. The phosphorylated molecule is then broken down in a series of reactions into two three carbon molecules (lysis).
3. Two molecules of NAD+ capture and are reduced to 2 molecules of
NADH + H+
3. Four molecules of ATP are produced by substrate phosphorylation
4. The end product pyruvate may then either undergo areobic respiration in the mitochondria or anaerobic respiration (fermentation).

Answer 6

lycolysis is a metabolic pathway by which a 6-carbon glucose (Glc) molecule is oxidized to two molecules of pyruvic acid (Pyr). The word glycolysis is derived from Greek γλυκύς (sweet) and λύσις (rupture). It is the initial process of most carbohydrate catabolism, and it serves three principal functions:

* The generation of high-energy molecules (ATP and NADH) as cellular energy sources as part of anaerobic and aerobic respiration.
* Production of pyruvate for the citric acid cycle as part of aerobic respiration.

Answer 7

In cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed organelle found in most eukaryotic cells.[1] These organelles range from 0.5–10 micrometers (μm) in diameter. Mitochondria are sometimes described as "cellular power plants" because they generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of the chemical energy.[2] In addition to supplying cellular energy, mitochondria are involved in a range of other processes, such as signaling, cellular differentiation, cell death, as well as the control of the cell cycle and cell growth.[3] Mitochondria have been implicated in several human diseases, including mitochondrial disorders[4] and cardiac dysfunction,[5] and may play a role in the aging process. The word mitochondrion comes from the Greek μίτος or mitos, thread + χονδρίον or chondrion, granule. Several characteristics make mitochondria unique. The number of mitochondria in a cell varies widely by organism and tissue type. Many cells have only a single mitochondrion, whereas others can contain several thousand mitochondria.[6][7] The organelle is composed of compartments that carry out specialized functions. These compartments or regions include the outer membrane, the intermembrane space, the inner membrane, and the cristae and matrix. Mitochondrial proteins vary depending on the tissue and the species. In humans, 615 distinct types of proteins have been identified from cardiac mitochondria;[8] whereas in Murinae (rats), 940 proteins encoded by distinct genes have been reported.[9] The mitochondrial proteome is thought to be dynamically regulated.[10] Although most of a cell's DNA is contained in the cell nucleus, the mitochondrion has its own independent genome. Further, its DNA shows substantial similarity to bacterial genomes.[11]

Answer 8

Lysis means to break down...etc
Glycol- would be in reference to Glucose,,,
So: GLycolysis is the break down of Glucose into 2 Pyruvate and 2 ATP and it occurs in teh cytosol of the cell during cellular respiration.

Answer 9

Mr. Earl Benjamin III
MS in Chemistry, Morgan State University
Presentation on 3/18/04
Review of Glycolysis
1. What is Glycolysis?
Glycolysis is the sequence of reactions that converts glucose into pyruvate with
the concomitant production of a relatively small amount of ATP. Glycolysis can
be carried out anerobically (in the absence of oxygen) and is thus an especially
important pathway for organisms that can ferment sugars. For example, glycolysis
is the pathway utilized by yeast to produce the alcohol found in beer. Glycolysis
also serves as a source of raw materials for the synthesis of other compounds. For
example, 3 phosphoglycerate can be converted into serine, while pyruvate can be
aerobically degraded by the Krebs or TCA cycle to produce much larger amounts
of ATP.
2. Why do animal need glycolysis?
Glycolysis is perhaps the first step in the of all energy producing.
3. Where does glycolysis occur?
Glycolysis occurs in most area of the cell.
4. What is/are the reactants/reagents necessary for glycolysis?
Glycolysis of requires glucose to produce energy.
5. What is/are the product of glycolysis?
Glycolysis produces a net amount of 2 ATP and 2NADH
4. Does this process need or use oxygen?
No it does not need large amounts of energy.
5. How much energy does glycolysis produce?
Glycosis produces 2ATP and 2 NADH which then goes into the Oxidative
Phosphorylation cycle which then produces more ATP.
6. What is the advantage of producing energy from glycolysis?
Glycolysis, is considered as the basis for all energy processes in the cell.
Althoug it only produces low levels of ATP, normally called basal levels, this
process also produces large quantities of NADH which when processed by the
Oxidative Phosphorylation pathway can produce large amount of energy.
Glycolysis can also be carried out throughout the cell, which gives it an advantage
over the TCA and Oxidative phosphorylation cycles that occur in the
mitochondria.
Review of Pyruvate Dehydrogenase (PDH) Complex
The fate of pyruvate depends on the cell energy charge. In cells or tissues with a high
energy charge pyruvate is directed toward fatty acid synthesis, but when the energy
charge is low pyruvate is preferentially oxidized to CO2 and H2O in the TCA cycle, with
generation of 15 equivalents of ATP per pyruvate.
What is the Pyruvate Dehydrogenase (PDH) Complex ?
The PDH Complex is a series of biological step that prepare the pyruvate
produced in glycolysis to go into the TCA cycle. These processes chemically
convert pyurvate to Acetyl-CoA that can then enter the TCA cycle.
What are the reactants for the PDH cycle?
Pyruvate from glycolysis
What is the product of the PDH cycle?
Acetyl-CoA
What is the advantage of using this process?
This process allow for the chemical conversion of pyruvate into Acetyl-Co A
which can then be inserted into the TCA cycle for processing.
Review of Citrus Acid Cycle
1.What is the Citrus Acid Cycle?
Krebs cycle or the citric acid cycle or tricarboxylic acid cycle is the common
pathway to completely oxidize fuel molecules that mostly is acetyl CoA, the
product from the oxidative decarboxylation of pyruvate. It enters the cycle and
passes ten steps of reactions that yield energy and CO2.
Where does the Citrus Acid Cycle occur?
The mitochondrial membrane
Does the TCA Cycle need or use oxygen?
Yes. The Citrus Acid Cycle does need oxygen.
How much energy does the TCA cycle produce?
Per turn of the TCA cycle 3 NADH, 1 FADH2, and 1ATP
What is the reactant of the TCA cycle?
Acetyl-CoA produced from the pyruvate from glycolysis and converted by the
PDH complex. Citrate is also a reactant, which can come from OAA in the citrus
acid cycle.
What is the product of the TCA cycle?
In fact since the TCA cycle feed backs into itself there is no net products.
However, TCA cycle 3 NADH, 1 FADH2, and 1ATP are produced each turn.
What is the advantage of the TCA cycle?
The advantage of the TCA cycle is that it cycles that it can cycle which means
that it can repeat for several times to accumulate several products which can be either
used as direct energy or put into the oxidative phosphorylation pathway which can
produce large amounts of energy.
Citrus Acid Cycle Steps
Step 1:
Reaction: Acetyl CoA+Oxaloacetate to Citrate
Enzyme: Citrate synthase
Reaction type: Condensation
Description: Acetyl CoA condenses with oxaloacetate first,to form citryl
CoA. Then citryl CoA is hydrolyzed to citrate and CoA
Step 2.
Reaction: Citrate to cis-Aconitate
Enzyme: Aconitase
Reaction Type: Dehydration
Description: Citrate is isomerized to isocitrate by this first
dehydration and yields cis-aconitate as an
intermediate.
Step 3.
Reaction: cis-Aconitate to Isocitrate
Enzyme: Aconitase
Reaction Type: Hydration
Description: Hydration of cis-aconitate gives the interchange of H
atom and OH group from the step 2.
Step 4.
Reaction: Isocitrate to alpha-Ketoglutarate
Enzyme: Isocitrate dehydrogenase
Reaction Type: Oxidative decarboxylation
Description: Dehydrogenation of isocitrate occurs and yields
oxalosuccinate as an intermediate.Then CO2 leaves to
have alpha-ketoglutarate.This reaction gives NADH.
Step 5.
Reaction: alpha-Ketoglutarate to Succinyl CoA
Enzyme: alpha-Ketoglutarate dehydrogenase complex
Reaction Type: Oxidative decarboxylation
Description: This mechanism is almost as same as the reaction of
the oxidative decarboxylation of pyruvate to acetyl
CoA by pyruvate dehydrogenase complex. This
reaction gives one NADH.
Step 6.
Reaction: Succinyl CoA to Succinate
Enzyme: Succinyl CoA synthetase
Reaction Type: Substrate-level phosphorylation
Description: The thioester bond of succinyl and CoA is an energy rich
bond. Thus only this step gives a high-energy phosphate
compound,GTP from the couple reactions of the thioester
bond cleavage and the phosphorylation of GDP.
Step 7.
Reaction: Succinyl CoA to Succinate
Enzyme: Succinate dehydrogenase
Reaction Type: Oxidation
Description: The two hydrogens of succinate leave to an acceptor,
FAD. Then this reaction yields fumarate and FADH2.
Step 8.
Reaction: Succinate to Fumarate
Enzyme: Succinate dehydrogenase
Reaction Type: Oxidation
Description: The two hydrogens of succinate leave to an acceptor,
FAD. Then this reaction yields fumarate and FADH2.
Step 9.
Reaction: Fumarate to Malate
Enzyme: Fumerase
Reaction Type: Not described.
Description: Not described.
Step 10.
Reaction: Malate to Oxaloacetate
Enzyme: Malate dehydrogenase
Reaction Type: Oxidation
Description: Malate is dehydrogenated to form oxaloacetate. The
hydrogen acceptor is NAD. So this reaction yields
NADH.

Answer 10

http://en.wikipedia.org/wiki/Glycolysis