Bio C: Organisation (PAPER 1) Flashcards
Effect of PH on the rate of reaction of amylase
1 Use marker to label test tubes for different values of buffer solution
2 drop iodine into each well of spotting tile
3 2cm of amylase into test tube
4 pipette 1cm of buffer solution into test tube
5 add starch into test tube n begin timer
6 Heat with Bunsen burner & measure temp
7 use pipette to extract starch/amylase solution and drop into first well of spotting tile
8 record time for starch to be digested by amylase
9 repeat steps for different PHs
Order of the digestive system
Mouth Oesophagus Stomach Small intestine Large intestine
Role of the mouth in the digestive system
Chewing physically breaks down the food.
Produces salivary amylase to breakdown carbohydrates.
Role of the stomach in the digestive system
Contracts muscular walls mixing the food
Produces protease to breakdown protein
Produces hydrochloric acid to kill bacteria and provide right conditions for protease
Role of the small intestine in the digestive system
Digested food is absorbed into the bloodstream
Produces digestive enzymes from pancreas and gall bladder
Role of the gall bladder in the digestive system
Provides bile which breaks down fat into smaller molecules providing larger surface area.
Bile also neutralises the stomach acid as it is alkaline.
Role of the large intestine in the digestive system
Absorbs excess water leaving DOODOO faeces
How do enzymes work?
Enzymes substrate fits into the active site creating an enzyme substrate complex through its lock and key shape. The enzyme then breaks down the substrate bonds and the products leave the active site.
Capillaries
Narrow vessels which form networks to supply cells and organs between veins and arteries.
Walls one cell thick to decrease diffusion distance increasing substance transfer rate.
arteries and veins comparison
Veins carry deoxygenated blood towards the heart at a low pressure so they have thin, less muscular walls and have a wide lumen.
Arteries carry oxygenated blood away from the heart at high pressure so they have thick, elastic walls and a narrow lumen.
Role of valves in veins
prevent back flow of blood ensuring blood only pumps in one direction.
Blood structure
The blood is made up of red blood cells, white blood cells and platelets, all within a plasma.
Plasma
The plasma transports all the different blood cells around the body as well as CO2, hormones and nutrients.
Red blood cells
The red blood cells transport oxygen around the body.
They have a biconcave shape to increase the surface area and have no nucleus so they can bind more oxygen molecules due to more space.
Haemoglobin,
White blood cells
The white blood cells have a role in the immune system and ingest pathogens by producing antibodies.
