Organisation Flashcards
(32 cards)
what is a tissue?
a group of cells with a similar structure and function
what is an organ?
group of tissues working together for a specific function.
what are the 3 main nutrients?
carbohydrates, proteins and lipids; they have to be digested
what happens during digestion?
large food molecules are broken down into small molecules by enzymes. the small molecules can be absorbed into the bloodstream.
what happens in the mouth?
food is chewed, enzymes in the saliva begin to digest the starch into smaller sugar molecules.
what happens in the stomach?
enzymes begin the digestion of proteins. the stomach also contains hydrochloric acid which help the enzymes to digest the proteins. the churning action of the stomach muscles turns the food into a fluid increasing the surface area for enzymes to digest.
what happens in the small intestine?
receives the food next, and produces protease and lipase enzymes to complete digestion. food is absorbed into bloodstream either by diffusion or active transport
what does that pancreas do?
the pancreas produces enzymes: carbohydrates, lipase, protease and amylase. releases enzymes which continue the digestion of starch and protein. they also start the digestion of lipids.
what does the liver do?
the liver releases bile which helps to speed up the digestion of lipids. nile also neutralises the acid released from the stomach
what happens in the large intestine?
water is absorbed into bloodstream - faeces is released out of body.
what happens in the gall bladder?
where bile is stored, before it’s released into the small intestine
what do the salivary glands do?
produce amylase enzyme in the saliva
what are enzymes?
large protein molecules that have a groove on their surface called the active site; where the substrate attaches to.
how does the enzyme work?
the substrate has to fit into the active site otherwise the reaction won’t be catalysed. the enzyme will break down the substrate into the products. - lock and key theory
how does temperature affect enzyme action?
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. The optimum temperature is around 37°.
How does pH affect enzyme function?
The optimum pH for most enzymes is seven. If the pH is too extreme, the shape of the active site may be altered and the enzyme may no longer work.
where are carbohydrases proteases and lipases produced in the body
- carbohydrases: amylase - salivary gland and pancreas
- proteases: pepsin - stomach; others - pancreas and small intestine
- lipases: pancreas and small intestine
what is the role of carbohydrases in the digestive system?
convert carbohydrates into simple sugars, breaks down starch.
role of proteases in the digestive system
Break down proteins into amino acids
role of lipases in the digestive system
Breakdown lipids into fatty acids and glycerol
how are the products of digestion used?
Used to build a bigger molecules, such as carbohydrates and proteins. Glucose is used as a substrate in respiration.
what is the role of bile in the digestive system?
are you is alkaline neutralises the acid and makes conditions alkaline.
it emulsifies fat breaks them down into tiny droplets, which give it a bigger surface area of fat for the enzyme lipase to work on, which makes digestion faster
tests to determine whether a solution is made up of carbohydrate, protein or lipid
- Benedict’s test for sugars (turns brick red)
- iodine test for starch (turns blue black)
- biuret test for protein (turns purple
- sudan III test for lipids (red layer forms on top)
what is the purpose of the circulatory system?
Carries oxygen, another useful substances to bodily tissues and removes waste substances
