Copyright

Role of Glucose in Cellular Respiration

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Role of NADH in Cellular Respiration

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:00 What Is Cellular Respiration?
  • 0:55 Glucose In Cellular…
  • 1:35 Steps Of Cellular Respiration
  • 3:12 Importance Of Glucose
  • 5:03 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Amanda Robb
This lesson is on the role of glucose in cellular respiration. In this lesson, we'll explain what cellular respiration is and what we need to start with to get the end products. We'll specifically look at the importance of glucose in this process.

What Is Cellular Respiration?

Sugar is everywhere in our world, from packaged foods in our diet, like tomato sauce, to homemade baked goods, like pies. In fact, sugar is even the main molecule in fruits and vegetables. The simplest form of sugar is called glucose. Glucose is getting a bad rap lately and many people are cutting sugar out from their diet entirely. However, glucose is the main molecule our bodies use for energy and we cannot survive without it. The process of using glucose to make energy is called cellular respiration.

The reactants, or what we start with, in cellular respiration are glucose and oxygen. We get oxygen from breathing in air. Our bodies do cellular respiration to make energy, which is stored as ATP, and carbon dioxide. Carbon dioxide is a waste product, meaning our bodies don't want it, so we get rid of it through exhaling.

Glucose in Cellular Respiration

To start the process of cellular respiration, we need to get glucose into our cells. The first step is to eat a carbohydrate-rich food, made of glucose. Let's say we eat a cookie. That cookie travels through our digestive system, where it is broken down and absorbed into the blood. The glucose then travels to our cells, where it is let inside. Once inside, the cells use various enzymes, or small proteins that speed up chemical reactions, to change glucose into different molecules. The goal of this process is to release the energy stored in the bonds of atoms that make up glucose. Let's examine each of the steps in cellular respiration next.

Steps of Cellular Respiration

There are three steps of cellular respiration: glycolysis, the citric acid cycle, and oxidative phosphorylation. The main role of glucose in each of these steps is to provide energy in its bonds.

Step 1: Glycolysis

In glycolysis, glucose enters the cell. Next, a series of enzymes convert it to a different form called pyruvate in the main compartment of the cell, the cytoplasm. Two pyruvate are formed from one glucose. During this process two ATP are formed, as are two more of another energy-rich molecule called NADH. NADH collects electrons from the bonds in glucose. It transports them to the last step, oxidative phosphorylation, where they will be used to make ATP. So, the end purpose of glycolysis is to get a little ATP and harvest electrons in the bonds of glucose.

Step 2: Citric Acid Cycle

In the citric acid cycle, the pyruvate is converted to another molecule called acetyl Co-A. Acetyl Co-A undergoes a similar sequence of conversions to harvest more electrons in the form of NADH and make two ATP. These steps occur in the powerhouse of the cell, the mitochondria.

Step 3: Oxidative Phosphorylation

In the last step, all of the electrons harvested in the form of NADH from glucose are transported to the membrane of the mitochondria. Here these electrons are used by proteins in the cell to ultimately convert the energy stored in them to ATP. In doing this, oxygen combines with the electrons and hydrogen ions to make water. Without oxygen, the glucose would be useless, and the chain of reactions in cellular respiration would get backed up and stop.

To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 160 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create An Account
Support