organisation Flashcards
(104 cards)
what is a cell?
the basic building block of a living organism
what is a tissue?
a group of cells with a similar structure and function working together
what is an organ?
a collection of tissues working together rot perform a specific function
what is an organ system?
a group of organs working together to perform specific functions.
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 salivary gland in the digestive system?
the pancreas and the salivary glands are glands which produce digestive juices containing enzymes
what is the role of the stomach in the digestive system?
produces hydrochloric acid, which kills ant 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 bloodstream
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 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 enzyme 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 catalyze
- build larger molecules from smaller molecules
- changing one molecule to another
- breaking down larger molecules into smaller molecules
what is the lock and key hypothesis of enzyme function?
the shape of the enzyme active site and the substrate are complementary, so it can bind together to form an enzyme-substrate complex
how does temperature affect enzyme action
up to a certain point, increasing temperature increases enzyme action, as molecules have higher kinetic energy. however, above a certain temp, 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.
how does PH affect enzyme function?
the optimum PH for most enzymes is 7. If the PH is too extreme, the shape of the active site may be altered and the enzyme may no longer work
where are carbohydrates produced in the body?
amylase: salivary gland
pancrease and maltase: small intestine
where are proteases produced in the body?
pepsin: stomach
others: pancreas and small intestine
where are lipases produced in the body?
pancreas and small intestine
what is the role of carbohydrates in the digestive system?
carbohydrates 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 the protease in the digestive system?
protease breaks down proteins into amino acids
what is the role of lipases in the digestive system?
lipase break down lipids into fatty acids and glycerol
how are the products of digestion used?
they are used to build bigger molecules such as carbohydrates and proteins. glucose is used as a substrate in respiration