2. FUNCTION OF THE CITRIC ACID
CYCLE
The citric acid cycle, also known as the Krebs cycle or
the tricarboxylic acid cycle, is at the centre of cellular
metabolism, playing a starring role in both the process
of energy production and biosynthesis.
It finishes the sugar-breaking job started in glycolysis
and fuels the production of ATP in the process.
3. THE IMPORTANCE OF THE CITRIC
ACID CYCLE
The Krebs cycle is the second of three stages of cellular
respiration, in whichglucose, fatty acids and certain
amino acids, the so-called fuel molecules, are oxidized
(see Figure).
The oxidation of these molecules is primarily used to
transform the energy contained in these molecules into
ATP.
4. WHAT DOES CITRIC ACID CYCLE DO
The net result of these two closely linked pathways is
the oxidation of nutrients to produce usable chemical
energy in the form of ATP.
In eukaryotic cells, the citric acid cycle occurs in the
matrix of the mitochondrion.
5. WHAT DOESTHE CITRIC ACID CYCLE
PRODUCE
The citric acid cycle is a series of reactions that produces
two carbon dioxide molecules, one GTP/ATP, and
reduced forms of NADH and FADH2.
6. DOES CITRIC ACID CYCLE REQUIRE
OXYGEN
The Krebs cycle results in 2 ATP molecules for each
glucose molecule run through glycolysis. ...
Though the Krebs cycle does not directly require
oxygen, it can only take place when oxygen is present
because it relies on by-products from the electron
transport chain, which requires oxygen.
7. WHAT ARETHE PRODUCTS OFTHE CITRIC ACID
CYCLE?
Each acetyl coenzyme A proceeded once through the
citric acid cycle.
Therefore, in total, it created 6 NADH + H+ molecules,
two FADH2 molecules, four carbon dioxide molecules,
and two ATP molecules.That's a lot of products!
8. WHAT HAPPENSTOTHE CITRIC ACID CYCLE
WITHOUT OXYGEN?
Though the Krebs cycle does not directly
require oxygen, it can only take place when oxygen is
present because it relies on by-products from the
electron transport chain, which requires oxygen.
The Krebs cycle is therefore an aerobic process
9. WHAT ISTHE PURPOSE OFTHE CITRIC ACID
CYCLE?
The main goal of the citric acid cycle is to produce
energy by oxidizing acetyl-CoA.
The energy produced comes in the form of NADH and
FADH2.
These molecules donate their electrons (energy) to the
electron transport chain, which ultimately drives
oxidative phosphorylation.
10. WHY CITRIC ACID CYCLE IS CALLEDTCA CYCLE?
The citric acid cycle (CAC) – also known as
the tricarboxylic acid (TCA) cycleor the Krebs cycle –is
a series of chemical reactions used by all aerobic
organisms to release stored energy through the
oxidation of acetyl-CoA derived from carbohydrates,
fats, and proteins into carbon dioxide and chemical
energy in the
11. HOW MANYTIMES DOESTHE CITRIC ACID CYCLE
OCCUR?
How many times does the citric acid cycle occur for each
molecule of glucose? The citric acid cycle
occurs twice for each molecule of glucose.
Three NADHs, 1 FADH2, and 1 ATP are formed, while 2
total carbons are lost in the molecule CO2 as pyruvate is
oxidized.
12. WHERE DOES CITRIC ACID CYCLE OCCUR?
In prokaryotic cells, the citric acid cycle occurs in the
cytoplasm;
In eukaryotic cells the citric acid cycle takes place in the
matrix of themitochondria.
13. HOW IS OXYGEN USED INTHE CITRIC ACID
CYCLE?
The electron carriers NADH and FADH are sent to the
final step of cell respiration, which is respiratory electron
transport.
The Krebs cycle does not use oxygen, though it does
stop in the absence of oxygen because it runs out of
NAD and FAD.
Many of your body's cells can also use fatty acids in
the Krebs cycle.
14. WHY ISTHE CITRIC ACID CYCLE OXYGEN
DEPENDENT
The NADH and FADH2 proceed on to the electron
transport chain. ...
Though theKrebs cycle does not directly
require oxygen, it can only take place when oxygen is
present because it relies on by-products from the
electron transport chain, which requires oxygen.
The Krebs cycle is therefore an aerobic process.
