2.2 Animal Tissues, organ and systems Flashcards
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 the salivary Gland are glands which produce digestive juices containing enzymes.
What is the role of the stomach in the digestive system?
Produces hydrochloric acid - which kills any bacteria present and provides the optimum acidic pH for the protease enzyme to function.
What is the role of the small intestine in the digestive system?
The small intestine is the site where soluble food molecules are absorbed into the blood stream
What is the role of the liver in the digestive system?
Produces bile (stored in the gallbladder) which emulsifies lipids and allows the lipase enzyme to work more efficiently.
What is the role of the large intestine in 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 speed up the rate of biological reactions (the breakdown of food) without being used up.
How does the shape of an enzymes affect its function?
Enzymes have a specific active site which is complementary to their substrate
What is metabolism?
The sum of all the reactions in a cell or 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 are complementary, so can bind together to form an enzyme-substrate complex.
How does the temperature effect enzyme action?
Up to a certain point, increasing temperature increases enzyme action, as molecules have a higher kinetic energy. Above a certain temperature, the shape of the active site is altered and the enzyme becomes denatured, so it can no longer catalyse the reaction. The optimum temperature is around 37’C
How does pH affect enzyme function?
The optimum pH for most enzymes is 7 (apart from proteases in 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 are carbohydrates, proteases and lipases produced in the body
Carbohydrates: amylase - salivary gland and pancreas; maltase - small intestine.
Proteases: pepsin - stomach; others - pancreas and small intestine.
Lipase: pancreas and small intestine.
What is the role of carbohydrase’s in the digestive system?
Carbohydrase’s break down carbohydrates into monosaccharides and disaccharides. Amylase breaks down starch into maltose, and maltase breaks down maltose into glucose.
What is the role of proteases in the digestive system?
Proteases break down protein into amino acids.
Why is the wall of the left ventricle thicker?
The left ventricle has to pump blood at a high pressure around the whole body.
How are the products of digestion used?
They are used to build bigger molecules such a carbohydrates and proteins. Glucose is used as a substrate in repiration.
What is the role lipases in digestive system?
Lipases break down lipids into fatty acids and glycerol
Where is bile and stored in the body?
Bile is made by the liver and stored in the gallbladder.
What is the heart?
An organ that pumps blood around the body
What is the role of bile in the digestive system?
Bile is an alkaline substance which neutralises the hydrochloric acid secreted by the stomach.
Bile emulsifies lipids to form droplets - this increases the surface area for the lipase enzyme work on.
How does the double circulatory system work?
- One pathway carries blood from the heart to the lungs - where the gaseous exchange of oxygen and carbon dioxide takes place.
- One pathway carries blood from the heart to the tissues
What is the purpose of the circulatory system?
Carries oxygen and other useful substances to body tissues and removes waster substances.