Anonymous
Jun 10
List the chemical changes that a starch molecule undergoes from the time it reaches the duodenum to the time its carbon atoms become part of carbon dioxide molecules.
Say where in the body do these changes occur.
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ChatGPT
Jun 10
1. In the duodenum, starch molecules are broken down into smaller molecules by the enzyme amylase, resulting in the formation of maltose, maltotriose, and dextrins.
2. These smaller molecules are further broken down into glucose molecules by enzymes in the small intestine, such as maltase, sucrase, and lactase.
3. Glucose molecules are absorbed into the bloodstream and transported to cells throughout the body.
4. Inside the cells, glucose molecules undergo glycolysis, a series of chemical reactions that convert glucose into pyruvate, producing ATP in the process.
5. Pyruvate molecules are then converted into acetyl-CoA, which enters the citric acid cycle (Krebs cycle) in the mitochondria.
6. In the citric acid cycle, acetyl-CoA is further broken down into carbon dioxide molecules, releasing more ATP and other energy-rich molecules.
7. The carbon atoms from the original starch molecule are ultimately released as carbon dioxide during the citric acid cycle and are exhaled from the body as waste.
2. These smaller molecules are further broken down into glucose molecules by enzymes in the small intestine, such as maltase, sucrase, and lactase.
3. Glucose molecules are absorbed into the bloodstream and transported to cells throughout the body.
4. Inside the cells, glucose molecules undergo glycolysis, a series of chemical reactions that convert glucose into pyruvate, producing ATP in the process.
5. Pyruvate molecules are then converted into acetyl-CoA, which enters the citric acid cycle (Krebs cycle) in the mitochondria.
6. In the citric acid cycle, acetyl-CoA is further broken down into carbon dioxide molecules, releasing more ATP and other energy-rich molecules.
7. The carbon atoms from the original starch molecule are ultimately released as carbon dioxide during the citric acid cycle and are exhaled from the body as waste.
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Google Gemini AI
Jun 10
Chemical Changes of Starch in the Digestive Tract
1. Duodenum
- Amylase from the pancreas breaks down starch into smaller polysaccharides (dextrins) and disaccharides (maltose).
2. Small Intestine
- Dextrins are further broken down into maltose by dextrinases in the small intestine.
- Maltose is hydrolyzed into two glucose molecules by maltase.
3. Enterocytes (Intestinal Cells)
- Glucose is absorbed into enterocytes via facilitated diffusion.
4. Liver
- Absorbed glucose is converted into glucose-6-phosphate (G6P) in liver cells.
- G6P is either:
- Stored as glycogen (glycogenesis) or
- Metabolized (glycolysis) to pyruvate.
5. Metabolic Pathways
- Pyruvate enters the citric acid cycle (Krebs cycle) in mitochondria.
- During the Krebs cycle, pyruvate is oxidized and broken down, releasing carbon atoms.
- Carbon atoms are released as carbon dioxide (CO2) during oxidative phosphorylation.
Overall Chemical Change:
Starch → Dextrins → Maltose → Glucose → Glucose-6-phosphate → Pyruvate → CO2
1. Duodenum
- Amylase from the pancreas breaks down starch into smaller polysaccharides (dextrins) and disaccharides (maltose).
2. Small Intestine
- Dextrins are further broken down into maltose by dextrinases in the small intestine.
- Maltose is hydrolyzed into two glucose molecules by maltase.
3. Enterocytes (Intestinal Cells)
- Glucose is absorbed into enterocytes via facilitated diffusion.
4. Liver
- Absorbed glucose is converted into glucose-6-phosphate (G6P) in liver cells.
- G6P is either:
- Stored as glycogen (glycogenesis) or
- Metabolized (glycolysis) to pyruvate.
5. Metabolic Pathways
- Pyruvate enters the citric acid cycle (Krebs cycle) in mitochondria.
- During the Krebs cycle, pyruvate is oxidized and broken down, releasing carbon atoms.
- Carbon atoms are released as carbon dioxide (CO2) during oxidative phosphorylation.
Overall Chemical Change:
Starch → Dextrins → Maltose → Glucose → Glucose-6-phosphate → Pyruvate → CO2
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