Biology Paper 1 - Organisation

a group of cells with a similar function

a group of tissues working together

a group of organs working together to form an organ system

Food is chewed in the mouth. Enzyme in the saliva digest the starch into smaller molecules. It passes down the oesophagus into the stomach. In the stomach enzymes digest proteins. The churning of the stomach muscles turn the food into a fluid. It passes down to the small intestine which chemicals are released into. It passes down to the large intestine and released as faeces

Produces bile

Speed up the digestion of lipid and neutralises the acid release of stomach

Enzymes have a ACTIVE site where the SUBSTRATE attaches to it perfectly

Amylase

Protease

Lipase

1)Increased collision per second

2)Maximum frequency of successful collisions

3)The active site is denatured and the enzyme doesn't work

Enzymes have an optimum ph and too acidic or alkaline it denatures

Drop of iodine in a spotting tile. places 3 test tubes containing ph 5, starch and amylase into a water bath. Now combine 3 solutions into one test tube and mix. Then put in water bath and after 30s put a drop of solution into the spotting tile and it will be blue black showing starch present. Take a sample every 30s until iodine remains orange showing starch no longer present. Repeat using different PH.

Test tube of food solution. Few drops of iodine. If starch present iodine turns blue black. If no starch it stays orange

Test tube of food solution. 10 drops of Benedict solution place the test tube in a beaker with hot water. If sugar present the Benedict solution colour will change, green little and brick red a lot of sugar.

Test tube of food solution. Add biuret solution. If protein present it will change to purple. iF NOT

Test tube of food solution. Add a few drops of distilled water and ethanol. Gently shake. White cloudy emulsion form.

Grind food with Mortar

Add distilled water

Mix

Filter

Massively increase the surface area for the absorption of molecules

Increase the surface area even further

Thin membrane which ensures a short diffusion path

Very good blood supply increase the concentration gradient

The blood passes from heart to the lungs in the pulmonary artery

Brings in deoxygenated blood from the body

Oxygenated blood passes from heart to the lungs in the pulmonary vein

Oxygenated blood pumps from heart to the body in the aorta

Blood enters left and right atrium

Atria contract and blood forced into ventricles

Ventricles contract forcing blood out the heart

Valves stop backflow of blood

Deoxygenated blood into lungs

vs

Oxygenated blood into organs

natural resting heart rate

Right atrium

Thick walls to withstand high pressure of blood

Valves to stop back flow of blood

Low pressure blood + Thin walls

High pressure blood + Thick walls

Transport dissolved substances along the body, like c02, urea

Transport oxygen from lungs to body cells

Oxygen carrying molecule haemoglobin

No nucleus so more room for haemoglobin

Part of the immune system by making antibodies

Contains nuclei which has the DNA to allow them to do their job

To help the blood to clot

Protein extracted from blood can be useful for antibodies

To replace blood lost from injury

Thin walls so diffusion path is short

Large surface area

growth of abnormal cells in one arrea

invade neighbouring tissues and move into the bloodstream to spread around the body

decrease blood cholestrol

low cost

drugs need to be taken long term

side effects

effect of stent is immediaterapid recovery from operation

risk of infection

risk of blood clot