Glycolysis

Glycolysis Knowledge Challenge

Test your understanding of glycolysis with our engaging quiz! Explore the essential biochemical processes and understand how glucose metabolism plays a crucial role in cellular energy production.

Key Features:

11 thought-provoking questions
Varied question formats: Multiple choice, checkboxes, and open-ended
Perfect for students and educators alike

11 Questions3 MinutesCreated by LearningPathway245

During the preparatory, or energy investment, phase of glycolysis, …A…molecules of ATP are hydrolyzed per molecule of glucose. During the payoff phase, ….B…molecules of ATP are synthesized per molecule of glucose. The net yield is….C….molecules of ATP per molecule of glucose.

Write down the two chemical structures for the transition of phosphoenolpyruvate to pyruvate. When considering the state of the carboxylic acid group, assume that the pyruvate is at physiological pH (around 7.4)

3 In your own words, explain why it is necessary to convert 2phosphoglycerate into phosphoenolpyruvate (PEP) instead of directly transferring a phosphate group to ADP from 2-phosphoglycerate.

Answer: Dehydration of 2-phosphoglycerate establishes a double bond between carbon 3 and 2 during formation of PEP. This constrains the mesomeric freedom of the whole molecule and in particular constrains the freedom to move for the negatively charged phosphate at C2 relative to the negatively charged carboxyl group at C1. This reaction decreases entropy, destabilizing the molecule by increasing its free energy by about a factor of 3.5. Establishing the double bond at this position is like tightening up the string on a bow. Now the phosphate bound at C2 can be transferred and bound to ADP leading to the formation of ATP and rearranging the double bond a carbonyl group can be established at C2 maintaining part of the free energy buildup in PEP and drive the transformation of PEP into Pyruvate

You know that ATP is a major energy currency of cells. What are TWO energetic reasons that ATP is well-suited for this role?

The chemical structure of nucleotides makes reaction coupling particularly simple for ATP.

ATP is readily synthesized from higher-energy molecules by substrate-level phosphorylation.

ATP sequentially donates all three phosphates with an equal free energy of hydrolysis, thus it can store a large amount of energy in smaller "packets".

ATP phosphorylates many other molecules that have a lower free energy of hydrolysis.

ATP phosphorylates many other molecules that have a higher free energy of hydrolysis.

What are TWO common features of reactions that are coupled together by cells?

They are catalyzed by different enzymes

They are catalyzed by the same enzyme.

They share all of the same products and reactants

They share some of the same products and reactants.

The difference of the standard free energies of the two reactions is exactly zero.

Select the appropriate enzyme names to label the boxes representing the steps in ethanol fermentation catalyzed by the enzymes.

1=Pyruvate Decarboxylase

2=Pyruvate Decarboxylase

1=Alcohol Dehydrogenase

2=Alcohol Dehydrogenase

Hat does this reaction represent?

The final step in ethanol fermentation - the conversion of acetaldehyde to ethanol.

The second-to-last step in ethanol fermentation - the conversion of pyruvate to acetaldehyde

The final step in lactate fermentation - the conversion of pyruvate to lactate.

The final step in glycolysis - the conversion of PEP to pyruvate.

Why do human cells utilize lactate fermentation under anaerobic conditions?

To generate additional ATP from each molecule of glucose

To regenerate NAD+ to support continued glycolysis

To regenerate NADH to support continued glycolysis

To generate lactate to enter the Cori cycle

Glycolysis

Glycolysis Knowledge Challenge

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