enzymes and digestion Flashcards
function of digestive system
to digest food absorb the nutrients obtained from digestion
state the steps of the digestion system
- food chewed in mouth
- passes down oesophagus
- reaches stomach
- passes into small intestine
- passes into large intestine
- passes to rectum before exiting through anus
role of salivary glands
produce amylase to begin to digest starch into smaller sugar molecules
role of stomach
-produces hydrochloric acid to kill bacteria and create right pH for protease enzyme to work
-produce protease enzyme pepsin which begins digestion of proteins
-churns food with muscular walls to turn it into a fluid, increasing surface area for enzymes to digest
role of small intestine
-soluble food molecules are absorbed into bloodstream
-walls release enzymes (protease, amylase and lipase) to complete digestion
role of liver
-bile is produced to speed up digestion of lipid (emulsify fats), allowing lipase enzyme to work more efficiently
-bile also neutralises stomach acid
where is bile stored?
gallbladder
role of large intestine
-excess water is absorbed into the bloodstream, producing faeces
where are carbohydrases, lipases and proteases produced in the body?
-carbohydrase: amylase-salivary gland and pancreas, maltase-small intestine
-lipase: pancreas and small intestine
-protease: pepsin-stomach, others-pancreas and small intestine
role of carbohydrases
-break down carbohydrates
-amylase breaks down starch into maltose
-maltase breaks down maltose into glucose
role of proteases
-break down proteins into individual amino acids that are absorbed into the bloodstream
role of lipids
-break down lipids into fatty acids and glycerol
what are proteins?
long chains of amino acids
how are the products of digestion used?
used to build bigger molecules such as carbohydrates, lipids and proteins, some glucose is used in respiration
where is bile made and store?
made in liver and stored in gallbladder
role of bile
-alkaline substance which neutralises the hydrochloric acid produced by the stomach, creating optimum pH for enzymes in small intestine
-emulsifies lipids to form smaller droplets which increases surface area of lipase enzymes to work on therefore increasing rate it is broken down
word equation proteins
proteins ————-> amino acids
protease
enzymes
word equation lipids
lipid ————–> glycerol and
lipase fatty acids
enzyme
word equation starch
starch ————> maltose
amlyase and other
enzyme simple sugars
what does starch consist of?
a chain of glucose molecules
what does a lipid molecules consist of?
1 molecule of glycerol attached to 3 molecules of fatty acids
what is amylase?
an enzyme produced in the salivary glands and pancreas that breaks carbohydrates down into simple sugars
what is lipase?
an enzyme that is produced in the pancreas that breaks lipids down into fatty acids and glycerol
what is protease?
an enzyme produced in the stomach and pancreas that breaks proteins down into amino acids
why does the concentration of glucose increase near the start of the small intestine?
carbohydrates are broken down into sugar by carbohydrases
why does the concentration of glucose decrease near the end of the small intestine?
glucose is absorbed into blood by active transport
