Intro to Carbohydrate Metabolism - Video Tutorials & Practice Problems
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Intro To Carbohydrate Metabolism Concept 1
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Hey, everyone. So here we're going to say the process of harvesting energy from carbohydrates starts with digestion. Digestion itself is just the conversion of food to small molecules through mechanical and biochemical breakdown. Now, when we say mechanical, referring to the chewing and grinding down of food into smaller molecules, biochemical breakdown is just the use of hydrolysis to break down these larger molecules into smaller molecules. Now, in step A, we have our salivary alpha amylase enzyme. It hydrolyzes some starching glycogen into smaller polysaccharides and maltose. Remember polysaccharides are just polymers of glucose. So it's several glucose molecules connected by glycolytic linkages, maltose represents a dy saccharide. But we have two glucose molecules connected by a glycolic linkage. Now, here we're going to say that illegal sac rides are just are 3 to 10 monosaccharide connected together, they're produced through the hydrolysis of glycogen and starch and sometimes they're called dex. Now, here are stomach acid inactivates salivary alpha amylase and halts carbohydrate digestion. The stomach itself does not release any enzymes in terms of carbohydrate hydrolysis, but it does help to inactivate this particular enzyme. Now, here for step B, we're gonna say further hydrolysis in the small intestines produces a mixture of monosaccharide. Now, these mixture monosaccharide could be in the form of glucose, fructose, g lactose, right. So, these are things to keep in mind when we're starting to talk about carbohydrate metabolism.
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Intro To Carbohydrate Metabolism Concept 2
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When looking at the stages of food metabolism. Remember, we're starting out with our starch and glycogen and our disaccharide. So large sugar molecules, we use our salivary alpha amylase and step A to help break them down. By the time they reach our stomach, these polysaccharides are smaller in length. Some of them get to the point where there are disaccharide or illegal saccharide. And remember the stomach itself does not secrete any enzymes. What it does is it inactivates our salivary alpha amylase that halts carbohydrate digestion. It's in step B where we have further enzymes taking effect in the small intestines which will help break down these larger sugar sugar molecules into monosaccharide. From there, we go into steps, stages 23 and four where we have aceto coa formation, which then goes into the crept cycle or the citric acid cycle. Remember in this cycle, we have the creation of our electron carriers in the form of N A DH N FA DH two, we also have the production of some A TP as well as carbon dioxide. This N A DH can then go into the electron transport chain or oxidated phosphorylation that we know of to help to create even more A TP. In addition to this remember, stages, three and four are coined our common metabolic pathway. Now, the enzymes in the small intestines include pancreatic alpha amylase maltase, which helps to break down mal maltose sucrase, which helps to break down sucrose and lactase which helps to break down lactose, right. So keep in mind these different stages of our food metabolism and the different types of enzymes that we find in the small intestines that help to break down our larger carbohydrates into monosaccharide.
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example
Intro To Carbohydrate Metabolism Example 1
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Here, it says which of the following carbohydrates is hydrolyzed by the enzyme in saliva. So we know that we have our starches and our polysaccharides and our disaccharide initially. And the enzyme that we're using is our salivary alpha alys. This is our enzyme test. It ends with ace. This enzyme would basically react with our carbohydrate carbohydrates and with ose. So the sugar would have to be a Milos answer. He would be option a, the Amy's carbohydrate will be affected by the salivary alpha amylase. The enzyme found within our saliva. This helps to break down our food into smaller carbohydrate molecules.
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Problem
Problem
Where does the digestion of milk sugar take place? Which enzyme catalyzes the reaction?
A
Mouth, α-amylase
B
Small intestine, lactase
C
Stomach, α-amylase
D
Small intestine, α-amylase
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