organisation and the digestive system Flashcards
tissues
a group of similar cells working together to perform a specific function
e.g. muscular tissue, glandular tissue, epithelial tissue
organs
a group of tissues working together to perform a specific function
e.g. muscular tissue to churn stomach contents
glandular tissue to produce digestive juices
organ systems
a group of organs working together to perform a specific function
e.g. gas exchange system, digestive system, circulatory system
digestive system with a muscular tube that includes
glands that produce enzymes
stomach where digestion occurs
liver, which produces bile
small intestine, where digestion occurs
large intestine, where water is absorbed producing faeces
villi
a large surface area to absorb soluble food molecules
thin wall to provide a a short diffusion path
good blood supply to carry food molecules
carbohydrates
made of units of sugar
complex- starch and cellulose- made of long chains of simple sugar
simple sugar- one unit of sugar
lipids
molecules made of three molecules of fatty acids linked to a molecule of glycerol
proteins
long chains of amino acids which are folded to form a specific shape
other molecules can fit into these specific shapes
food test for starch
iodine
food test for sugar
blue benedicts solution
food test for protein
blue bieuret reagent
food test for lipids
ethanol
enzymes
biological catalysts- they speed up reactions
active site
in an enzyme where its substrate molecule can fit
metabolism
the sum of all the reactions that take place in a cell or in the whole body
what can enzymes do
build large molecules from many smaller ones
change one molecule into another one
break down large molecules into smaller ones
effect of temperature on enzyme action
reactions take place quicker when its warmer
risks changing the shape of the active site which leads to the enzyme being denatured
effect of ph on enzyme action
each enzynme has an optimum ph where the active site has the best shape so that the enzyme works most efficiently
digestive enzymes
are produced by specialised cells in glands and in the lining of the small intestine.
comes into contact with food so it is digested
amylase
produced in salivary glands, pancreas, small intestine
catalyses the digestion of starch into sugars
what does the digestive system do
breaks food into smaller pieces to increase the surface area for enzymes to work on
mixes the food with digestive juices contain the enzymes
has muscles to move the food along
has areas with different levels of ph
absorbs the small soluble food molecules into the blood in the small intestine
proteases
produced by the stomach, the pancreas, the small intestine
catalyses the breakdown of protein into amino acids
bile
neutralises the stomach acid
makes the conditions in the small intestine slightly alkaline
emulsifies fats to increase the surface area of the fats for lipase enzymes to act upon
lipase
produced by the pancreas and the small intestine
catalyses the break downs of lipids (fats and oils)
