b3 Flashcards
what is a cell
the basic building blocks of living organisms
what is a tissue
group of cells with a similar structure and function
what is an organ
aggregations of tissues performing specific functions
organ system
group of organs that have been organised into a system which work together to form organisms
function of mouth in the digestive system
mechanical digestion happens.
teeth chew the food. also place where salivary amalyse is secreted which is an enzyme.
oesophagus in digestive system
connects mouth to the stomach, where food goes down after being swallowed
stomach in digestive system
has hydrochloric acid which kills bacteria in food and also provides the optimum pH for some enzymes to work in
has muscles that also mechanically digest food
small intestine
where absorbtion of digested food molecules into the blood happen. the illeum is long and lined with villi which increases the surface area
large intestine
absorbs water from remaining material to produce faeces
pancreas
produces the digestive enzymes
liver
produces bile to help with the digestion of lipids
gall bladder
stores bile and releases into small intestine when lipids need to be digested
what are enzymes?
biological catalysts that are made from proteins
- they speed up chemical reactions that happen in the body and are not used up
explain the lock and key theory
the substrate binds to the active site of the enzyme because the shape of the active site is complimentary to the shape of the enzyme.
this causes a chemical reaction to produce smaller molecules.
what does amalyse do
breaks down starch into glucose. secreted by small intestine, pancreas and salivary glands
site of digestion is small intestine and salivary glands