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HUMAN DIGESTIVE SYSTEM - Coggle Diagram
HUMAN DIGESTIVE SYSTEM
Why do we need food?
Nutrition is the process by which organisms obtain energy for growth, metabolism and repair
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Our body needs the nutrients in food for survival. Three important nutrients are carbohydrates, proteins and fats
Nutrients like glucose and amino acids, are small, soluble molecules. They can pass through the selectively permeable cell surface membrane to enter cells
Nutrients like starch, proteins and fats, are large insoluble molecules. They cannot pass through the selectively permeable cell surface membrane to enter cells.
PROCESSES:
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DIGESTION:
The physical as well as chemical break down fr large insoluble food molecules to smaller soluble food molecules
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PERISTALSIS:
The whole alimentary canal is made up of muscles. Movement of food is controlled by the contraction and relaxation of these muscles. We call this peristalsis
Peristalsis is a series of wave-like muscle contractions that helps to squeeze food along the alimentary canal.
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As food passes through, the muscles in fornt of the food relax while the muscles behind the food contract. This action squeezes food along the canal
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Chemical digestion:
It is a process whereby large and complex substances are broken down into smaller and simpler substances by the action of enzymes.
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ENZYMES:
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Enzymes are complex proteins that speed up the rate of chemical reactions. Digestive enzymes in particular speed up the process of digestion.
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Carbohydrase (amylase, maltase) acts on large carbohydrate molecule to form simple sugars
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EMULSIFICATION;
It is a process whereby large fat globules are broken down into smaller fat droplets. This increases the surface area fats so that they can be digested by lipases faster
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