. a group of different tissues working together to perform a common function
why is the digestive system considered a organ system
because it contains a group of organs that work together to perform the common function of digesting and absorbing our food
what are enzymes ?
type of catalyst that is made by living organisms called biological catalysts
how do enzymes work ?
they speed up chemical reactions lowering energy needed
what is the lock and key model ?
Model of enzyme-substrate interaction.
2 reasons why we can’t make o ur cells even warmer to increase the rate of reactions ?
heating out cells would require a lot of energy . higher temperatures could damage our cells
factors that effect the rate of reaction and functioning of enzymes
temperature, ph
what do we call a enzyme that doesn’t bind to the substrate
de natured
what does the term optimum mean for enzyme temperature
the temperature at which enzyme activity is highest
explain how increasing the temperature can cause an enzyme to denature ?
high temperatures start to break the bonds holding the enzyme together this causes the enzymes and its active site to change shape this means the enzymes active site will no longer be complementary to the substrate
what are nutrients ?
Substances essential for growth, development, and maintenance of the body.
Inorganic substances with a specific chemical composition and crystal structure.
what is the role of fibre ?
Digestion stops us getting constipation
what is the role of water in our body ?
Hydration. replace what we have lost from sweating
why do we need carbohydrates ?
Energy
what food group do fats and oils make up
lipids
why do we need lipids ?
Energy storage, cell membrane structure, insulation, and hormone production.
which disease can be cause by a lack of vitamin c ?
Scurvy
why is iron important in our diet
component of haemoglobin. which is the protein in red blood cells that allows them to transport oxygen around the body a lack of iron can lead to anaemia
what are biological molecules ?
Molecules found in living organisms and produced by cells
what are nutrients ?
Substances essential for growth, development, and maintenance of the body.
what are monomers that join together to form proteins called ?
amino acids
what enzyme is carbohydrate broken down by ?
Amylase
which enzyme breaks down proteins ?
Protease
which enzyme breaks down lipids ?
Lipase
what is carbohydrates broken down into by enzymes ?
maltose
what is proteins broken down into
amino acids
what are lipids broken down into
glycerol and fatty acids
what is starch broken down into ?
Glucose
how does bile help with the digestion of lipids ?
Emulsifies the lipids which increases the surface area
how does the digestive system digest food ?
Enzymes.
how the digestive system absorbs food ?
Absorption
how do we break down food
breakdown food by physically chewing then the saliva from the salivary glands makes the food softer and easier to be broken down
what is the role of the gullet ?
Swallowing
what is the role of the stomach ?
contracts muscular walls, uses pepsin breaks down proteins and produces hydrochloride acid which kills bacteria
what are the main roles of gall bladder ?
releases bile which neutralises acid from the stomach. emulsifying fats which gives fats much bigger surface area. BILE IS STORED IN GALL BLADDER MADE IN LIVER
what is the pancreases role
it has lots of digestive enzymes, produces enzymes to aid digestion pancreatic juices
how is villi adapted to its role ?
there are many villi which gives them a large total surface area over which to absorb nutrients they have a single layer of cells on their surface which means nutrients only have to diffuse a short distance. good food supply