Difference Between Glucose and ATP

Key Difference – Glucose vs ATP
 

Glucose and ATP are organic compounds composed of carbon, hydrogen and oxygen. Other than these three elements, ATP contains Phosphorus and Nitrogen. Cellular respiration breaks down glucose into water and carbon dioxide producing 38 net ATP molecules. ATP is the energy containing nucleotide in cells while the energy found in glucose is used to make ATP. The key difference between glucose and ATP is the composition of these two molecules.

CONTENTS
1. Overview and Key Difference
2. What is Glucose
3. What is ATP
4. Side by Side Comparison – Glucose vs ATP
5. Summary

What is Glucose?

Glucose is a simple sugar which is widely used in living organisms. The chemical formula of glucose is C₆H₁₂O₆. It is a monosaccharide which functions as a precursor for many carbohydrates found in the organisms. In plants, glucose is produced by photosynthesis and used as a substrate for energy production. In animals, glucose is a prime energy source. In prokaryotes, glucose subjects to either aerobic respiration, anaerobic respiration, or fermentation and converts into energy molecules. Therefore, glucose can be considered as one of a primary energy source of living organisms.

Glucose is broken down completely to water and carbon dioxide by aerobic respiration. It starts with glycolysis and going via Krebs cycle and electron transport chain. In the end, it converts the energy in the nutrient glucose into 38 ATP and other two waste products. Anaerobic respiration produces less number of ATP from a glucose molecule since glucose is undergoing incomplete combustion. Some microorganisms ferment lactose to lactic acid or alcohol produce energy under anoxic conditions. All these processes use glucose as the starting substrate for ATP production.

High demand of energy by the brain requires an energy source to supply energy constantly. Glucose serves as the energy source of brain fuel in human. Also, it acts as an energy source for muscle and other tissues as well. Apart from the energy production, glucose involves in manufacturing of structural molecules in the human body. Glucose transports in the body through blood. Glucose concentration in the blood should be tightly regulated to prevent abnormal levels causing health complications such as hypoglycemia, diabetes, weight gain, etc.

What is ATP?

Adenosine triphosphate (ATP) is the energy currency in living cells. It is a nucleotide composed of three major components; namely, ribose sugar, triphosphate group, and adenine base. ATP molecules bear high energy within the molecules. Upon an energy request for growth and metabolism, the ATP hydrolyses and releases its energy for cellular needs. Three phosphate groups are responsible for the function of the ATP molecule because the energy is stored in ATP molecule inside the phospho-anhydride bonds between phosphate groups. The most commonly hydrolyzing phosphate group of the ATP molecule is the farthest phosphate group (Gamma-phosphate) from the ribose sugar.

ATP molecule bears high energy within it. Therefore, it is an unstable molecule. Hydrolysis of ATP is always feasible via an exergonic reaction. The terminal phosphate group removes from the ATP molecule and converts into Adenosine diphosphate (ADP) when the water is present. This conversion releases 30.6 kJ/mol energy to the cells. ADP converts back into ATP immediately inside the mitochondria by ATP synthase during the cellular respiration.

What is the difference between Glucose and ATP?

Summary – Glucose vs ATP

Glucose is one of a primary energy source found in the living organisms. The energy of the glucose is converted into ATP molecules by different processes of the cell such as aerobic respiration, anaerobic respiration and fermentation. ATP is the nucleotide which releases and stores energy in the cell. It acts as the energy currency of the living organisms. ATP molecule contains high energy which was initially found in the glucose molecules. One glucose molecule results net 38 ATP molecules during the aerobic respiration. Energy of one glucose molecule is stored in the 38 molecules of ATP in cells.

References

1. Aronoff, Stephen L., Kathy Berkowitz, Barb Shreiner, and Laura Want. “Glucose Metabolism and Regulation: Beyond Insulin and Glucagon.” Diabetes Spectrum. American Diabetes Association, 01 July 2004. Web. 06 Mar. 2017.
2. Philips, Ron Milo & Ron. “» How much energy is released in ATP hydrolysis?” Cell biology by the numbers Footer Comments. N.p., n.d. Web. 06 Mar. 2017

Image Courtesy

1. Glucose in Cellular Respiration – By OpenStax College [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons https://commons.wikimedia.org/wiki/File:2503_Cellular_Respiration.jpg
2. ADP ATP Cycle – By Muessig (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons https://commons.wikimedia.org/wiki/File%3AADP_ATP_cycle.png