Glycolysis - Biochemistry
The Organic Chemistry Tutor・25 minutes read
Glycolysis involves splitting glucose into two pyruvate molecules, capturing energy in the form of ATP and NADH. The process consists of two phases: an investment phase requiring energy input and a payoff phase producing more energy than invested.
Insights
- Glycolysis breaks down glucose into pyruvate, capturing energy in the form of ATP and NADH, with the process divided into an investment phase that requires energy input and a payoff phase that produces more energy than invested.
- Specific enzymes and magnesium ions play crucial roles in catalyzing the various steps of glycolysis, with irreversible reactions occurring in steps 1, 3, and 10, while the rest are reversible based on their biochemical delta G values.
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Recent questions
What is glycolysis?
Glycolysis is a metabolic pathway that involves breaking down a glucose molecule into two pyruvate molecules, generating ATP and NADH in the process.
How many phases are in glycolysis?
Glycolysis consists of two phases: the investment phase (steps 1-5) and the payoff phase (steps 6-10).
What is the role of enzymes in glycolysis?
Enzymes in glycolysis catalyze specific reactions, such as phosphorylating glucose, converting molecules, and producing ATP, facilitating the breakdown of glucose into pyruvate.
What is the significance of magnesium ions in glycolysis?
Magnesium ions act as cofactors in several steps of glycolysis, assisting enzymes in catalyzing reactions like phosphorylation and isomerization, crucial for the pathway's progression.
How does glycolysis produce energy?
Glycolysis produces energy in the form of ATP by oxidizing glucose to pyruvate, generating NADH and ATP molecules through a series of enzymatic reactions, ultimately yielding a net gain of ATP molecules.
Related videos
Summary
00:00
"Overview of Glycolysis: Energy Production Process"
- Glycolysis involves splitting a glucose molecule into two pyruvate molecules, each representing a three-carbon molecule.
- Energy released during glycolysis is captured in the form of ATP and NADH.
- The net reaction of glycolysis involves glucose reacting with two NAD+ molecules and two ADP units to produce two pyruvate molecules, two NADH molecules, two hydrogen ions, two ATP molecules, and two water molecules.
- Glycolysis consists of two phases: the investment phase (steps 1-5) and the payoff phase (steps 6-10).
- The investment phase requires energy input, while the payoff phase produces more energy than invested.
- Step 1 of glycolysis involves phosphorylating glucose to create glucose 6-phosphate using the enzyme hexokinase and a magnesium ion.
- Step 2 converts glucose 6-phosphate to fructose 6-phosphate through a reversible reaction facilitated by phospho hexose isomerase and a magnesium ion.
- Step 3 phosphorylates fructose 6-phosphate into fructose 1,6-biphosphate using phospho fructo kinase and a magnesium ion.
- Step 4 cleaves fructose 1,6-biphosphate into glyceraldehyde 3-phosphate and dihydroxyacetone phosphate, catalyzed by the atylase enzyme.
- Steps 1, 3, and 10 of glycolysis are irreversible, while the rest are reversible based on their biochemical delta G values.
21:39
Glycolysis: Enzymes and ATP Production Summary
- Isomers are species with the same number of atoms but different structures, like the example of five hydrogen atoms, six oxygen atoms, and a phosphorus atom.
- Rearrangement reactions involve isomers and are catalyzed by isomerase enzymes.
- Triose phosphate isomerase is the enzyme needed for a three-carbon keto sugar with a phosphate group attached.
- In glycolysis step six, two molecules of G3P enter the payoff phase, requiring doubling of ATP and NADH molecules produced.
- G3P is oxidized to 1,3-bisphosphoglycerate, while NAD+ is reduced to NADH in the conversion process.
- The enzyme glyceraldehyde 3-phosphate dehydrogenase catalyzes the oxidation of G3P to 1,3-bisphosphoglycerate.
- Step seven of glycolysis involves the conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate, producing ATP through substrate-level phosphorylation with the enzyme phosphoglycerate kinase.
- Magnesium ions are required for the reaction in step seven of glycolysis.
- Step eight of glycolysis involves the conversion of 3-phosphoglycerate to 2-phosphoglycerate by phosphoglycerate mutase, requiring a magnesium ion cofactor.
- Step nine of glycolysis is a dehydration reaction converting 2-phosphoglycerate to phosphoenol pyruvate catalyzed by enolase enzyme.
- The final step, step ten, converts phosphoenol pyruvate to pyruvate with the enzyme pyruvate kinase, transferring a phosphate group to ADP to produce ATP, resulting in a net gain of two ATP molecules in glycolysis.
