Glycolysis and The Krebs Cycle Flashcards
What is ATP?
Adenosine triphosphate
- The cells energy currency
What is anaerobic cellular respiration?
When energy is produced in the absence of oxygen through glycolysis
What is dephosphorylation?
The hydrolysis/removal of a phosphate group from a molecule
What is fermentation?
The process of oxidizing NADH back to NAD+ with a final electron acceptor using an inorganic or organic compound,
- Occurs in the absence of oxygen
What is the GLUT protein?
An integral membrane protein that transports glucose
What is the definition of glycolysis?
The process of breaking glucose into 2 three-carbon molecules with the production of ATP and NADH
What is isomerase?
An enzyme that converts a molecule into its isomer
What is Phosphorylation?
The addition of a high energy phosphate to a compound
- Usually a metabolic intermediate, protein, or ADP
What is Pyruvate?
A three-carbon sugar that can be decarboxylated and oxidized to make acetyl CoA. which enters the citric acid cycle under aerobic conditions
- The final product of glycolysis
What is a redox reaction?
A chemical reaction that has both an oxidation and reduction reaction
What is substrate-level phosphorylation?
Production of ATP from ADP using the excess energy from a chemical reaction and a phosphate group from a reactant
What is the process of glycolysis?
- 2 Phosphates are added to a glucose molecule at the expense of two ATP
- This results in a 6-carbon diphosphate molecule and ADP
- The 6-carbon molecule is split into two 3-carbon molecules
- Each of these is oxidized sequentially until they become pyruvate, this process uses a coenzyme that is reduced at the same time called NAD+
- ATP is formed as a result
- In aerobic conditions, the pyruvate is further oxidized to create more ATP
In anaerobic, it is converted into lactic acid
What is the 6-carbon diphosphate molecule?
Simply a glucose molecule with 2 extra phosphate molecules bound to it
How does pyruvate differ in aerobic and anaerobic conditions?
- In aerobic conditions, the pyruvate oxidizes further into more ATP
- In anaerobic conditions, the pyruvate is converted into lactic acid
Where does the Kreb cycle take place?
Mitochondria
What molecule enters the Kreb cycle?
Acetyl-CoA
- A 2C molecule and a carrier molecule of CoA
How does Pyruvate become Acetyl-CoA?
When pyruvate enters the mitochondria, it is oxidized into Acetyl-CoA in the presence of NAD+
- Products: Acetyl CoA + CO2 + NADH
What happens to the Acetyl-CoA after it enters the Kreb Cycle? (Step 1)
- It bonds with a 4C molecule to become a 6C molecule
- It then is oxidized into a 5C molecule in the presence of NAD+
- Products: 5C molecule + CO2 + NADH
What happens to the 5C molecule during the Kreb Cycle? (Step 2)
- It is oxidized in the presence of NAD+ into a 4C molecule, while also releasing a molecule of ATP
- Products: 4C molecule + CO2 + NADH + ATP
What happens to the 4C molecule during the Kreb Cycle? (Step 3)
- The 4C molecule is further oxidized in the presence of FAD^2+ and NAD+
- Products: 4C molecule + FADH2 + NADH
- This 4C molecule is identical to the one that Acetyl-CoA bonded to at the start of the Kreb cycle
How many NADH are produced during the Kreb cycle?
3
- including the oxidation of pyruvate: 4
How many ATP are produced during the Kreb cycle?
1
When is ATP produced during the Kreb Cycle?
When the 5C molecule is oxidized
How many FADH2 are produced during the Kreb cycle?
1
How many times does the Kreb Cycle occur for each glucose molecule?
Twice, one for each pyruvate produced from glycolysis
What is Acetyl-CoA?
A combination of an acetyl group and coenzyme A
- The acetyl group is derived from an oxidized private
- The coenzyme A is made from pantothenic acid, a B-group vitamin
What is aerobic respiration?
Process in which organisms convert energy in the presence of oxygen
What is the citric acid/ TCA cycle?
Also known as the Kreb cycle,
- TCA is the chemical group name of citric acid
- A series of enzyme-catalyzed reactions of central importance in all living organisms
Who made the Krebs cycle?
Hans Krebs
- He also identified the pathway of pigeon flight muscles in the 1930s
What is the mitochondrion matrix?
The innermost compartment of the mitochondrion
