# Glycolysis ## Introduction to Glycolysis ### Overview Glycolysis is a crucial metabolic pathway where one molecule of glucose (a 6-carbon compound) is split into two molecules of pyruvate (each a 3-carbon compound). This process occurs in multiple steps and involves a series of enzyme-catalyzed reactions. ### Cellular Location **Where in the cell does glycolysis take place?** - in the intermembrane space of the mitochondrion - in the mitochondrial matrix - in the cell membrane - in the cytoplasm Glycolysis occurs in the **cytoplasm** of the cell. ### Inputs and Outputs #### Initial Stages At the beginning of glycolysis, glucose is phosphorylated by the addition of phosphate groups, using ADP and NAD+, to eventually produce ATP and NADH. **Inputs Used:** - Glucose - ADP - NAD+ **Outputs Produced:** - 2 molecules of pyruvate - 2 ATP (net yield) - 2 NADH #### Diagram Explanation 1. **Breaking Down Glucose**: - Glucose is initially phosphorylated and broken down into two 3-carbon molecules. 2. **Energy Investment and Payoff**: - ADP gains a phosphate group to form ATP. - NAD+ gains electrons and a proton (H+) to form NADH. ### Check Your Understanding **1. What is an outcome of glycolysis?** - the breakdown of a pyruvate molecule into two smaller glucose molecules - the breakdown of a glucose molecule into two smaller pyruvate molecules - the breakdown of NADH into NAD+ and high energy electrons - the breakdown of glucose into molecules of carbon dioxide The correct answer is the **breakdown of a glucose molecule into two smaller pyruvate molecules**. **2. Why does the breakdown of glucose net 2 molecules of ATP instead of 4?** - because only 2 ADP molecules are available in the cytoplasm - because most of the energy from glucose is lost to the environment - because the breakdown of glucose requires an input of energy to begin - because all reactions require an input of energy The correct answer is **because the breakdown of glucose requires an input of energy to begin**. ### Conclusion Glycolysis is a critical energy-yielding pathway that supplies cells with ATP and

# Glycolysis ## Introduction to Glycolysis ### Overview Glycolysis is a crucial metabolic pathway where one molecule of glucose (a 6-carbon compound) is split into two molecules of pyruvate (each a 3-carbon compound). This process occurs in multiple steps and involves a series of enzyme-catalyzed reactions. ### Cellular Location Where in the cell does glycolysis take place? - in the intermembrane space of the mitochondrion - in the mitochondrial matrix - in the cell membrane - in the cytoplasm Glycolysis occurs in the cytoplasm of the cell. ### Inputs and Outputs #### Initial Stages At the beginning of glycolysis, glucose is phosphorylated by the addition of phosphate groups, using ADP and NAD+, to eventually produce ATP and NADH. Inputs Used: - Glucose - ADP - NAD+ Outputs Produced: - 2 molecules of pyruvate - 2 ATP (net yield) - 2 NADH #### Diagram Explanation 1. Breaking Down Glucose: - Glucose is initially phosphorylated and broken down into two 3-carbon molecules. 2. Energy Investment and Payoff: - ADP gains a phosphate group to form ATP. - NAD+ gains electrons and a proton (H+) to form NADH. ### Check Your Understanding 1. What is an outcome of glycolysis? - the breakdown of a pyruvate molecule into two smaller glucose molecules - the breakdown of a glucose molecule into two smaller pyruvate molecules - the breakdown of NADH into NAD+ and high energy electrons - the breakdown of glucose into molecules of carbon dioxide The correct answer is the breakdown of a glucose molecule into two smaller pyruvate molecules. 2. Why does the breakdown of glucose net 2 molecules of ATP instead of 4? - because only 2 ADP molecules are available in the cytoplasm - because most of the energy from glucose is lost to the environment - because the breakdown of glucose requires an input of energy to begin - because all reactions require an input of energy The correct answer is because the breakdown of glucose requires an input of energy to begin. ### Conclusion Glycolysis is a critical energy-yielding pathway that supplies cells with ATP and

Concepts of Biology

1st Edition

ISBN:9781938168116

Author:Samantha Fowler, Rebecca Roush, James Wise

Publisher:Samantha Fowler, Rebecca Roush, James Wise

Chapter4: How Cells Obtain Energy

Section: Chapter Questions

Problem 17CTQ: Both prokaryotic and eukaryotic organisms carry out some form of glycolysis. How does ha fact...

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