organisation and digestive system Flashcards
what is a organ system?
a group of organs which work together to perform a specific function
what is a tissue?
a group of similar cells that work together to perform a particular function
what is the role of the digestive system?
it breaks down and absorbs food
what is an organ?
a group of tissues that work together to perform a certain function
what are the three main nutrients that food contains?
protein, carbohydrates and lipids
what happens in the mouth?
the food is chewed in the mouth and enzymes in the salvia begin to digest the starch into smaller sugar molecules
where does the food pass to get to the stomach?
oesophagus
in the stomach, what begins the digestion of proteins?
enzymes
in the stomach, what helps the enzymes to digest proteins?
hydrohalic acid
what action of stomach muscles turns the food into a fluid?
churning
how does turning the food into a fluid help enzymes to digest?
it increases the surface area
what part of the body releases chemicals into the small intestine?
liver & pancreas
what does the pancreas release?
enzymes
what does the liver release?
bile
what do enzymes do in the small intestine?
continue the digestion of starch and protein and also start the digestion of lipids
what does bile do?
helps speed up the digestion of lipids and also neutralises acid released from the stomach
what do the walls of the small intestine release?
enzymes
in the small intestine, what happens to the small food molecules produced
absorbed into the bloodstream wither by diffusion or active transport.
in the large intestine where is the water absorbed into ?
the bloodstream
what is some of the glucose used for ?
respiration
if the substrate does not fit perfectly in the active site, what happens?
the enzyme cannot break down the substrate
what are enzymes and what do they do?
enzymes are large protein molecules and they have a groove on their surface called the active site, this active site is where the substrate attaches to. they also catalyse chemical reactions
which enzymes is proteins broken down by?
protease
what enzymes break down carbohydrates?
carbohydrases
in the case of starch what is carbohydrase called?
amylase
what does starch consist of?
a chain of glucose molecules
what is the product o the reaction catalysed by amylase?
sugars
describe the role of digestive enzymes in the process of digestion
they break down the food into smaller, soluble molecules that can pass easily through the walls of the digestive system allowing them to be absorbed into the bloodstream
two ways in which the products of digestion can be used by the body
any two from:
make new lipids, make new carbohydrates, make new proteins
name the organ where bile is produced and the organ where it is stored
produced: liver
stored: gal bladder
which organ is part of the nervous system?
eye
how is the stomach adapted to digest protein? give 3
produces protease
produces hydrochloric acid
to provide the correct pH for the
enzyme to work
what molecule does lipids consist of?
glycerol
which enzyme is lipid molecules digested by?
lipase
where do you find lipase?
the pancreatic fluid and the small intestine
where do you find lipase?
the pancreatic fluid and the small intestine
is bile an acid or alkaline?
alkaline
finish the sentence
bile_____ stomach acid
neutralises
when bile neutralises stomach acid, what does that do to the rate if lipid digestion by lipase?
increases
what is metabolism?
sum of all the reactions in a cell or body
at a certain temperature the enzyme is working at the fastest possible rate, what is this called?
optimum temperature
if we increase the temperature what happens to the activity of the enzyme
it increases, the reaction gets faster
if we increase the temperature what happens to the activity of the enzyme
it increases, the reaction gets faster
if the enzyme and substrate is moving faster what happens to the collisions between the substrate and the active site?
there are more collisions
if we increase the temperature past the optimum, what happens to the activity of the enzyme?
it decreases to zero
explain what happens to the enzyme molecule at high temperatures?
the shape of the active site changes and now the substrate no longer fits perfectly into the active site so the active site is now denatured
what happens if the active site is DENATURED
the enzyme can no longer catalyse the reaction
what happens to the active site if the conditions are too acidic or too alkaline?
it denatures
if the enzyme works best at an acidic ph, what type of enzyme could this be?
protease enzyme in the stomach
if the enzyme works best at an alkaline ph, what type of enzyme could this be?
an enzyme released from the pancreas into the small intestine(eg. lipase)
what test should you do to see if starch is present?
iodine
iodine test for starch- red iodine solution turns _____ to ______ if starch is present
yellow turns blue/black
what test should you do to see if sugar is present?
benedict’s test
blue benedict’s solution turns _________on heating if a sugar such as glucose is present
brick red
what test should you do to see if protein is present?
biuret test
____ biuret turns ____ if protein is present
blue
purple
what test should you do to see if lipid is present?
ethanol test
ethanol added to a solution gives a _____________ if lipid is present
cloudy white layer
