Glycolysis Flashcards

Questions and Answers

What is the goal of glycolysis?

To turn glucose into pyruvate, so it can enter into the Krebs cycle to produce more energy and generate ATP in the process.

What is the first step in the glycolysis process?

2-phosphoglycerate to Phosphophenol pyruvate

Dihydroxyacetone to Glyceraldehyde 3 phosphate

Glucose to Glucose 6 phosphate (correct)

Fructose 6 phosphate to Fructose 1,6 phosphate

What is the mechanism by which the first step in glycolysis occurs? What is expended in the process?

Phosphorylation; ATP

What enzyme phosphorylates glucose into glucose 6 phosphate in step 1?

Hexokinase Signup and view all the answers

What are the steps in glycolysis where ATP is used?

Step 1 and Step 3 Signup and view all the answers

What are the steps in glycolysis where ATP is gained?

Step 7 and Step 10 Signup and view all the answers

How many reactions are there in total in glycolysis?

10 Signup and view all the answers

What is step 2 in the glycolysis process?

Glucose 6 phosphate to Fructose 6 phosphate Signup and view all the answers

What enzyme facilitates the change from glucose 6 phosphate to fructose 6 phosphate in step 2 of glycolysis?

Phosphoglucose isomerase Signup and view all the answers

What are the 3 major types of enzymes involved in glycolysis?

Isomerases, Kinases, Aldolases Signup and view all the answers

What does a kinase do?

Phosphorylation/dephosphorylation (addition and subtraction of a phosphate) Signup and view all the answers

What does an isomerase do?

Changes shape, not composition Signup and view all the answers

What does an aldolase do?

Cleaves sugar into smaller sugars Signup and view all the answers

What is the third step in the glycolysis process?

Fructose 6 phosphate to Fructose 1,6 phosphate Signup and view all the answers

What enzyme adds a phosphate to fructose 6 phosphate to make fructose 1,6 phosphate in step 3 of glycolysis?

Phosphofructokinase Signup and view all the answers

What is needed by phosphofructokinase to produce fructose 1,6 phosphate from fructose 6 phosphate?

An ATP molecule (2nd used in glycolysis) Signup and view all the answers

What is the fourth step in the glycolysis process?

Fructose 1,6 phosphate to Dihydroxyacetone phosphate and Glyceraldehyde 3 phosphate Signup and view all the answers

Which of the molecules created in the fourth step cannot continue in the process of glycolysis as is?

Dihydroxyacetone phosphate Signup and view all the answers

How does fructose 1,6 phosphate get broken down into dihydroxyacetone and glyceraldehyde 3 phosphate?

Aldolase Signup and view all the answers

What is the fifth step in glycolysis?

Dihydroxyacetone phosphate to Glyceraldehyde 3 phosphate Signup and view all the answers

Which enzyme produces glyceraldehyde 3 phosphate from dihydroxyacetone molecules?

Triosephosphate isomerase Signup and view all the answers

How do we end up with 2 NET ATPs at the end of glycolysis instead of 1?

Because everything done after step 5 is done to both of the glyceraldehyde 3 phosphates produced in steps 4 and 5 Signup and view all the answers

What is step 6 in the glycolysis process?

Glyceraldehyde 3 phosphate to 1,3 bisphosphoglycerate Signup and view all the answers

What is the molecule called that helps the reaction in step 6 occur? What is produced from that molecule after the reaction takes place?

NAD; NADH Signup and view all the answers

What is the name of the enzyme that catalyzes the reaction in step 6?

Glyceraldehyde 3 phosphate dehydrogenase Signup and view all the answers

What is step 7 of glycolysis?

1,3 bisphosphoglycerate to 3-phosphoglycerate Signup and view all the answers

What is made by dephosphorylating 1,3 bisphosphoglycerate in step 7 of glycolysis?

ATP Signup and view all the answers

What is the enzyme called that facilitates the reaction in step 7?

Phosphoglycerate kinase Signup and view all the answers

What happens in step 8 of glycolysis?

3-phosphoglycerate to 2-phosphoglycerate Signup and view all the answers

What enzyme moves the phosphate from the 3 position to the 2 position on the phosphoglycerate molecule?

Phosphoglycerate mutase Signup and view all the answers

What is step 9 of glycolysis?

2-phosphoglycerate to phosphophenol pyruvate Signup and view all the answers

Study Notes

Glycolysis Overview

Glycolysis converts glucose into pyruvate, enabling entry into the Krebs cycle for energy production.
This process generates ATP during the conversion.

Glycolysis Steps and Key Reactions

Step 1: Glucose is phosphorylated to glucose 6 phosphate by the enzyme hexokinase using ATP.
Step 2: Glucose 6 phosphate is converted to fructose 6 phosphate by phosphoglucose isomerase.
Step 3: Fructose 6 phosphate is phosphorylated to fructose 1,6 phosphate using ATP with the enzyme phosphofructokinase.
Step 4: Fructose 1,6 phosphate splits into dihydroxyacetone phosphate and glyceraldehyde 3 phosphate via aldolase.
Step 5: Dihydroxyacetone phosphate is converted into glyceraldehyde 3 phosphate by triosephosphate isomerase.
Step 6: Glyceraldehyde 3 phosphate is transformed into 1,3 bisphosphoglycerate, producing NADH with the enzyme glyceraldehyde 3 phosphate dehydrogenase.
Step 7: 1,3 bisphosphoglycerate is dephosphorylated to 3-phosphoglycerate, generating ATP through phosphoglycerate kinase.
Step 8: 3-phosphoglycerate is converted to 2-phosphoglycerate by phosphoglycerate mutase.
Step 9: 2-phosphoglycerate is converted into phosphoenolpyruvate, with the removal of a water molecule.

Total Reactions and ATP Yield

Glycolysis involves a total of 10 chemical reactions.
ATP is used in Steps 1, 3, and gained in Steps 7 and 10, leading to a net gain of 2 ATP molecules.

Enzyme Functions

Kinases: Enzymes that add or remove phosphates, involved in multiple steps of glycolysis.
Isomerases: Enzymes like phosphoglucose isomerase and phosphoglycerate mutase that change the shape but not the composition of molecules.
Aldolases: Enzymes that cleave molecules into smaller sugars.

Important Molecules

NAD: Acts as a cofactor in Step 6, resulting in the formation of NADH.
ATP: Essential energy currency used and produced during glycolysis.

Additional Notes

The process of glycolysis results in two molecules of glyceraldehyde 3 phosphate for every glucose molecule, impacting ATP production efficiency.
The flow of energy and substrate changes throughout each step are crucial for cellular respiration and energy metabolism.

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Description

Test your knowledge on glycolysis with these flashcards. Learn about the steps and goals of glycolysis, including the conversion of glucose to pyruvate and the energy produced. Perfect for students studying biochemistry and cellular metabolism.