large multicellur organisms (humans) are made up of organ systems
the process in which cells become specialised for a particular job is called differentiation
differentiation occurs during the development of cells
specialised cells form tissues which form organs which form organ systems
muscular tissue contracts to move whatever its attached to
glandular tissues which makes and secretes chemicals like enzymes and hormones
epithelial tissue which covers some parts of the body like inside the gut
muscular tissue moves the stomach wall to churn up food
glandular tissue makes digestive juices to digest food
epithelial tissue covers inside and outside the stomach
glands e.g pancreas and salivary glands produce digestive juices
stomach and small intestine digest food
liver produces bile
small intestine absorbs soluble food molecules
large intestine absorbs water from undigested food leaving faeces
enzymes are catalyst produced by living things
you can make a reaction happen more quickly by raising the temperature but also unwanted ones too however enzymes act as a biological catalyst reducing high temperatures
a catalyst is a substance that increases the speed of the reaction without being changed or used up in the reaction
enzymes are large proteins and all proteins are made up of chains of amino acids
enzymes need the right PH and temperature
enzymes are the most active at the optimum temp
lock and key
A) active site
B) unchanged
in enzymes if the temp gets to hot some bonds can break
if PH isn`t correct bonds can break and cause enzymes to change shape
enzymes have an optimum PH its often 7
required pratical 1
A) amylase
B) iodine solution
C) browny orange
D) amylase solution
E) starch solution
rate = 1000 / time
digestive molecules break down big molecules
starch, proteins and fats are too big to pass through the wall of the digestive system
digestive system breaks down big molecules like fats and starch into small ones like sugars
small soluble molecules can easily pass through the walls of the digestive system into the blood stream
carbohydrase converts carbohydrates into into simple sugars
proteases coverts proteins into amino acids
lipases covert lipids into glycerol and fatty acids
bile neutralises the stomach acid and emulsifies fats
bile is stored in the gall bladder
bile is alkaline and neutralises hydrochloric acid in the stomach which is acidic