Amylose (a form of starch) and cellulose are both polymers of glucose. What is the main structural difference between them? What roles do these two polymers have in nature?

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Hi, everybody. And welcome back. Our next question says, the starch found in plants differs structurally from Glycogen found within animal tissues despite both being polymers, primarily composed of glucose. And then we have two questions. Number one, what is their main structural difference? And number two elaborate on their roles within the organisms in which they are found. So let's think about the structures of these two to see what their main difference is. In starch, we have a mixture of amylase and amy amylase is a straight chain molecule. So just this linear chain of glucose glucose residues and then Amycin is a branched chain which has a branching point approximately every 20 to 30 glucose molecules or glucose units, I should say, whereas Glycogen has just a single type of polymer which is a highly branched chain. And when we say highly branched compared to Amycin in Glycogen, the branches occur every 8 to 12 glucose units. So that would describe their main structural difference. So number one, and then there are roles in which the organisms are found. Well, they both serve the purpose of energy storage for their organisms. But in plants, uh starch is the primary energy storing mechanism. And since it's their, you know, primary energy storage used for both short and long term energy. Whereas in animals, Glycogen though also used for energy storage, that is secondary and short term energy storage. In terms of Glycogen, it provides rapid breakdown into glucose. And why is it secondary energy storage? And that's because again, the glycogen serves as a short term energy storage, but there's limited amounts of glycogen that can be, you know, stored and animals use fats to put in parenthesis fats for long term energy storage. Whereas plants have just the one molecule to meet all those needs. So once again, when we talk about starch versus glycogen, what is our main structural difference? And that is that starch has a mixture of amylase which is a straight chain and Amy ect as a branch chain, but branches every 2030 20 to 30 glucose units. Whereas Glycogen is a highly branched chain where branches occur every 8 to 12 glucose units. And then in terms of their roles within the organisms, they've found both molecules are used for energy storage in plants. Starch is the primary means of energy storage and in animals, this is a secondary form of energy storage, but it is secondary to fats for long term energy storage. So that is our answer for our two questions about differences between starch and Glycogen. See you in the next video

Amylose (a form of starch) and cellulose are both polymers of glucose. What is the main structural difference between them? What roles do these two polymers have in nature?

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Key Concepts

Polymers of Glucose

Structural Differences

Roles in Nature