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The Digestive System
Digestive Enzymes and Their Functions
Breaking Down Nutrients
- DIGESTIVE ENZYMES are crucial in breaking down large molecules like STARCH, PROTEINS, and FATS into smaller, soluble molecules. This allows them to be absorbed into the bloodstream.
There are THREE types of digestive enzymes
- CARBOHYDRASES break down carbohydrates into simple sugars.
- PROTEASES convert proteins into amino acids.
- LIPASES break down lipids into glycerol and fatty acids.
Examples of digestive enzymes:
- AMYLASE: A type of carbohydrase enzyme that breaks down STARCH into maltose (a simple sugar).
- PEPSIN: A type of protease enzyme that is produced in the STOMACH. It has a LOW OPTIMUM pH. The hydrochloric acid in the stomach provides a low pH for the pepsin to work at a faster rate. Pepsin breaks down PROTEINS into AMINO ACIDS.
Absorption and Utilisation of Digested Products
- Some products of digestion are used to synthesise new carbohydrates, proteins, and lipids.
- Other products are utilised in other ways, e.g. glucose is used in respiration to release energy.
The Digestive System & Enzymes
- Digestive enzymes are key in breaking down food into absorbable nutrients.
- These enzymes are produced by specialised cells in various digestive system GLANDS and the gut lining.
The Mouth
- Teeth CHEW the food
- SALIVARY GLANDS in the mouth secrete AMYLASE enzyme in saliva to begin carbohydrate digestion.
Oesophagus
- A tube that connects the mouth to the stomach
The Stomach
- Has muscular walls that churn food into smaller pieces
- It produces PEPSIN, a type of protease enzyme to break down PROTEINS
- It produces HYDROCHLORIC ACID to KILL BACTERIA and to provide the optimum pH for the pepsin to work in
The Liver
- Produces BILE, crucial for NEUTRALISING stomach acid and EMULSIFYING FATS into smaller droplets
- The bile is STORED in the GALL BLADDER.
The Pancreas
- It produces PROTEASE, CARBOHYDRASE, and LIPASE.
The Small Intestine
- It produces PROTEASE, CARBOHYDRASE, and LIPASE.
- This is where digestion is completed, where the broken down nutrients are ABSORBED into the bloodstream.
The Large Intestine
- The large intestine absorbs EXCESS WATER from digested food.
- Waste is eventually moved to the RECTUM as faeces and exits the body through the ANUS.
The Digestive System
Digestive Enzymes and Their Functions
Breaking Down Nutrients
- DIGESTIVE ENZYMES are crucial in breaking down large molecules like STARCH, PROTEINS, and FATS into smaller, soluble molecules. This allows them to be absorbed into the bloodstream.
There are THREE types of digestive enzymes
- CARBOHYDRASES break down carbohydrates into simple sugars.
- PROTEASES convert proteins into amino acids.
- LIPASES break down lipids into glycerol and fatty acids.
Examples of digestive enzymes:
- AMYLASE: A type of carbohydrase enzyme that breaks down STARCH into maltose (a simple sugar).
- PEPSIN: A type of protease enzyme that is produced in the STOMACH. It has a LOW OPTIMUM pH. The hydrochloric acid in the stomach provides a low pH for the pepsin to work at a faster rate. Pepsin breaks down PROTEINS into AMINO ACIDS.
Absorption and Utilisation of Digested Products
- Some products of digestion are used to synthesise new carbohydrates, proteins, and lipids.
- Other products are utilised in other ways, e.g. glucose is used in respiration to release energy.
The Digestive System & Enzymes
- Digestive enzymes are key in breaking down food into absorbable nutrients.
- These enzymes are produced by specialised cells in various digestive system GLANDS and the gut lining.
The Mouth
- Teeth CHEW the food
- SALIVARY GLANDS in the mouth secrete AMYLASE enzyme in saliva to begin carbohydrate digestion.
Oesophagus
- A tube that connects the mouth to the stomach
The Stomach
- Has muscular walls that churn food into smaller pieces
- It produces PEPSIN, a type of protease enzyme to break down PROTEINS
- It produces HYDROCHLORIC ACID to KILL BACTERIA and to provide the optimum pH for the pepsin to work in
The Liver
- Produces BILE, crucial for NEUTRALISING stomach acid and EMULSIFYING FATS into smaller droplets
- The bile is STORED in the GALL BLADDER.
The Pancreas
- It produces PROTEASE, CARBOHYDRASE, and LIPASE.
The Small Intestine
- It produces PROTEASE, CARBOHYDRASE, and LIPASE.
- This is where digestion is completed, where the broken down nutrients are ABSORBED into the bloodstream.
The Large Intestine
- The large intestine absorbs EXCESS WATER from digested food.
- Waste is eventually moved to the RECTUM as faeces and exits the body through the ANUS.
