Glycolysis Pathway Overview

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What is the primary purpose of the first stage of glycolysis?

To generate ATP

To convert glucose into fructose 1,6-bisphosphate (correct)

To allow for substrate channeling

To release toxic intermediates

What is the role of hexokinase in the first stage of glycolysis?

It cleaves fructose 1,6-bisphosphate into two 3-carbon molecules

It ensures the movement of substrates and products through the enzymes

It transfers a phosphoryl group from ATP to glucose to form glucose 6-phosphate (correct)

It catalyzes the isomerization of glucose

How many ATP molecules are consumed in the first stage of glycolysis?

0

2 (correct)

4

1

What is the purpose of the second phosphorylation step in the first stage of glycolysis?

To convert glucose into fructose 1,6-bisphosphate Signup and view all the answers

What is the purpose of the isomerization step in the first stage of glycolysis?

To convert glucose into fructose 6-phosphate Signup and view all the answers

How many ATP molecules are generated in the second stage of glycolysis?

4 Signup and view all the answers

What is the purpose of substrate channeling in glycolysis?

To ensure the movement of substrates and products through the enzymes Signup and view all the answers

Which of the following is a characteristic of glycolysis?

It is a common pathway to virtually all cells Signup and view all the answers

What is the purpose of the cleavage of fructose 1,6-bisphosphate in the first stage of glycolysis?

To produce glyceraldehyde 3-phosphate and dihydroxyacetone phosphate Signup and view all the answers

What is the primary function of the first stage of glycolysis in eukaryotic cells?

To convert glucose into fructose 1,6-bisphosphate Signup and view all the answers

Which enzyme catalyzes the irreversible conversion of fructose 6-phosphate to fructose 1,6-bisphosphate in glycolysis?

Phosphofructokinase (PFK) Signup and view all the answers

What is the primary function of triose phosphate isomerase in glycolysis?

Catalyzing the conversion of dihydroxyacetone phosphate into glyceraldehyde 3-phosphate Signup and view all the answers

What is the final product formed by the conversion of 2-phosphoglycerate into phosphoenolpyruvate (PEP) in glycolysis?

ATP Signup and view all the answers

Which enzyme is responsible for converting pyruvate to ethanol in alcoholic fermentation?

Alcohol dehydrogenase Signup and view all the answers

In the Galactose-Glucose Interconversion Pathway, what catalyzes the phosphorylation of galactose into galactose 1-phosphate?

Galactokinase Signup and view all the answers

Which molecule is formed when glyceraldehyde 3-phosphate undergoes oxidation-reduction using glyceraldehyde 3-phosphate dehydrogenase?

1,3-bisphosphoglycerate Signup and view all the answers

What is the net reaction of lactic acid fermentation?

$ ext{Glucose} + 2 ext{ Pi} + 2 ext{ ADP} \rightarrow 2 ext{ lactate} + 2 ext{ ATP} + 2 ext{ H}_2 ext{O}$ Signup and view all the answers

Which enzyme catalyzes the cleavage of fructose 1-phosphate into glyceraldehyde and dihydroxyacetone phosphate in the liver pathway for fructose metabolism?

$ ext{Fructose aldolase}$ Signup and view all the answers

$ ext{NAD}^+$ regeneration is essential for which metabolic pathway to continue?

$ ext{Glycolysis}$ Signup and view all the answers

$ ext{Phosphoenolpyruvate (PEP)}$ is converted to pyruvate by which enzyme in glycolysis?

$ ext{Pyruvate kinase}$ Signup and view all the answers

Which enzyme catalyzes the conversion of UDP-Galactose to UDP-Glucose?

UDP-Galactose 4-epimerase Signup and view all the answers

Which role does glucose 1-phosphate play in glycolysis?

Building blocks for biosynthetic reactions Signup and view all the answers

In muscle, which enzyme is primarily involved in feedback inhibition of glycolysis?

Phosphofructokinase Signup and view all the answers

Which enzyme controls the third irreversible step in glycolysis?

Pyruvate kinase Signup and view all the answers

What inhibits hexokinase in muscle?

Glucose 6-phosphate Signup and view all the answers

Which enzyme in the liver plays a key role in liver glucose phosphorylation?

Glucokinase Signup and view all the answers

What regulates phosphofructokinase in the liver by indicating abundant biosynthetic precursors and inhibiting further glycolysis?

Citrate Signup and view all the answers

'Gluconeogenesis involves bypassing three irreversible steps of glycolysis.' Which regulatory enzymes are key players in gluconeogenesis?

'Fructose 1,6-bisphosphatase and Glucose 6-phosphatase' Signup and view all the answers

'The balance between glycolysis and gluconeogenesis in the liver is sensitive to factors like energy charge.' Which enzymes are involved in this balance regulation?

'Phosphofructokinase 2 and Fructose bisphosphatase 2' Signup and view all the answers

What is the primary purpose of the phosphorylation step catalyzed by hexokinase in the first stage of glycolysis?

To trap glucose inside the cell Signup and view all the answers

Which of the following statements about the first stage of glycolysis is correct?

It requires the investment of two ATP molecules Signup and view all the answers

What is the primary purpose of the cleavage of fructose 1,6-bisphosphate in the first stage of glycolysis?

To produce two three-carbon molecules Signup and view all the answers

Which of the following is a key function of substrate channeling in glycolysis?

To prevent the release of toxic intermediates Signup and view all the answers

Which of the following statements about the second stage of glycolysis is correct?

It generates a net gain of two ATP molecules Signup and view all the answers

What is the primary function of the isomerization step in the first stage of glycolysis?

To convert glucose 6-phosphate to fructose 6-phosphate Signup and view all the answers

Which of the following statements about the first stage of glycolysis is incorrect?

It generates ATP for the cell Signup and view all the answers

Which of the following statements about glycolysis is correct?

It is a common pathway to virtually all cells, both prokaryotic and eukaryotic Signup and view all the answers

Which of the following statements about the products of glycolysis is correct?

The final products are two molecules of pyruvate and two molecules of ATP Signup and view all the answers

What is the primary purpose of the second phosphorylation step in the first stage of glycolysis?

To produce a compound that can be cleaved into two three-carbon molecules Signup and view all the answers

What is the purpose of UDP-glucose in galactose metabolism?

Convert to UDP-galactose for biosynthetic reactions Signup and view all the answers

How is glucose 6-phosphate primarily utilized in glycolysis?

For both ATP production and biosynthesis Signup and view all the answers

Which enzyme is not inhibited by glucose 6-phosphate in liver glucose phosphorylation?

Glucokinase Signup and view all the answers

In the liver, what regulates phosphofructokinase by inhibiting further glycolysis?

Citrate Signup and view all the answers

What enzyme catalyzes the conversion of glucose 1-phosphate to glucose 6-phosphate?

Phosphoglucomutase Signup and view all the answers

What serves as control points in the glycolysis pathway?

Enzymes controlling irreversible reactions Signup and view all the answers

Which regulatory enzymes are key players in gluconeogenesis by bypassing irreversible steps of glycolysis?

$ ext{Fructose 1,6-bisphosphatase}$ and $ ext{Glucose 6-phosphatase}$ Signup and view all the answers

What is the primary source of feedback inhibition in muscle glycolysis?

ATP Signup and view all the answers

What role does fructose 2,6-bisphosphate play in regulating phosphofructokinase 2?

Activates the enzyme Signup and view all the answers

Which enzyme catalyzes the conversion of glucose 6-phosphate to fructose 6-phosphate?

Phosphoglucose isomerase Signup and view all the answers

What is the primary function of the phosphofructokinase (PFK) enzyme?

Catalyzing the irreversible reaction of fructose 6-phosphate to fructose 1,6-bisphosphate Signup and view all the answers

Which enzyme catalyzes the conversion of dihydroxyacetone phosphate (DHAP) into glyceraldehyde 3-phosphate (GAP)?

Triose phosphate isomerase Signup and view all the answers

In the second stage of glycolysis, which enzyme catalyzes the conversion of glyceraldehyde 3-phosphate into 1,3-bisphosphoglycerate?

Glyceraldehyde 3-phosphate dehydrogenase Signup and view all the answers

What is the primary role of phosphoglycerate kinase in glycolysis?

Transferring a phosphoryl group from 1,3-bisphosphoglycerate to ADP, forming 3-phosphoglycerate and ATP Signup and view all the answers

Which enzyme catalyzes the rearrangement of 3-phosphoglycerate into 2-phosphoglycerate?

Phosphoglycerate mutase Signup and view all the answers

What is the primary function of enolase in glycolysis?

Converting 2-phosphoglycerate into phosphoenolpyruvate (PEP) Signup and view all the answers

Which enzyme catalyzes the irreversible reaction that converts phosphoenolpyruvate (PEP) to pyruvate and generates ATP?