B3 (Orginisation and the digestive system) Flashcards
What is a cell?
The building blocks of life.
What is a tissue?
A group of cells.
What is a organ?
A group of tissues.
What is an organ system?
A group of organs.
What is an organism?
A group of organ systems.
What is the main function of the digestive system?
To digest food and absorb the nutrients obtained from digestion.
What is the role of the pancreas and the salivary gland in the digestive system?
The pancreas and salivary glands are glands which produce digestive juices containing enzymes.
What is the role of the stomach in the digestive system?
Produce hydrochloric acid - which kills any bacteria present and provides the optimum acidic pH for the protease enzyme to function.
What is the role of small intestine in the digestive system?
The small intestine is the site where soluble food molecules are absorbed into the bloodstream.
What is the role of the liver in the digestive system?
Produces bile (stored in the gallbladder) which emulsified lipids and allows the lipase enzyme to work more efficiently.
What is the role of the large intestine in the digestive system?
Absorbs water from undigested food, producing faeces.
What is the role of enzymes in the digestive system?
Enzymes act as biological catalysts which speeds up the rate of biological reactions (the breakdown of food) without being used.
How does the shape of an enzyme affect its function?
Enzymes have a specific active site which is complimentary to their substrate.
What is metabolism?
The sum of reactions in an organism.
What types of metabolic reactions do enzymes catalyse?
- Building larger molecules from smaller molecules e.g glucose to starch.
- Changing one molecule to another e.g glucose to fructose.
- Breaking down larger molecules into smaller molecules e.g carbohydrates to glucose.
What is the lock and key hypothesis of enzyme function?
The shape of the enzyme active site and the substrate complementary, so they can bind together to form an enzyme-substrate complex.
How does the temperature affect enzyme action?
Up to a certain point , increasing temperature increases enzyme action, as molecules have a kinetic energy. Above a certain temperature, the shape of the active site is altered and the enzymes becomes denatures, so it can no longer catalyse the reaction, the optimum temperature is around 37 degrees.
How does pH affect enzyme function?
The optimum pH for most enzymes is 7 (apart from protease sin the stomach) . If the pH is too extreme, the shape of the active site may be altered and the enzyme may no longer work.
What is the role of carbohydrases in the digestive system?
Carbohydrases break down carbohydrates into monosaccharides and disaccharides. Amylase breaks down starch into maltose, and Maltese breaks down maltase
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