User:Cosy Kibble/sandbox

This is school revision =B2 Organisation=

Structure of the digestive system

 * 1) Mouth
 * 2) Oesophagus
 * 3) Stomach
 * 4) Small Intestine
 * 5) Large Intestine
 * 6) Rectum
 * 7) Anus

Bile

 * Produced in the pancreas and stored in the liver
 * High PH to neutralizes stomach acid
 * Emulsifies fats - providing a larger surface area for enzymes to work with

Tests for sugars

 * The test for sugars is known as "Benedict's Test'
 * Add Benedict's solution to food
 * Heat in a water bath

Test for starch

 * Add iodine solution to the food being tested
 * A positive result (the food contains starch) is the food turning a blue-black colour

Test for proteins

 * Biuret test is used to test for proteins
 * A positive test is indicated by the solution turning purple
 * Add 1cm(3) of biuret solution A to the food solution
 * Mix the solutions
 * Add 1cm(3) of biuret solution B and shake/stir

Carbohydrase

 * Break down carbohydrates into simple sugars such as maltose and glucose
 * Produced in salivary glands

Protease

 * Breaks down protein into amino acids
 * Produced in the liver and stored in the gall bladder

Lipase

 * Breaks lipids down into fatty acids and glycerol
 * Produced in the pancreas and small intestine

=B3 Infection and Response=

Pathogens
Pathogens are microbes that can cause diseases. There are a number of different pathogens: Protists - Eukaryotic cells that can spread via vectors
 * Bacteria - Small living cells that produce toxins and reproduce very quickly
 * Fungi -They produce spores and can penetrate human skin
 * Virus - Lives and reproduces inside cells, causing damage to the cells it resides in

HIV

 * Transmitted via exchange of bodily fluids - most commonly during unprotected sex
 * Initially causes flu like symptoms
 * Attacks the immune system causing AIDS

Measles

 * Measles is a viral disease
 * Symptoms include: fever, skin rash

Salmonella

 * Salmonella food poisoning is usually spread through poorly prepared food or food prepared in unhygienic conditions.
 * Symptoms of Salmonella include: vomiting, diarrhoea

Human Defenses against Microbes

 * Hairs and mucus in the nose - Trap and remove particles that could contain pathogens
 * Hydrochloric acid - Hydrochloric acid in the stomach kills bacteria
 * Skin - Waterproof barrier

Painkillers

 * Painkillers relieve symptons but do not kill pathogens

Antibiotics
Antibiotics are substances that kill bacteria but '''do not kill viral pathogens (viruses)
 * Specific antibiotics are used for specific bacteria.

Penicillin
The first antibiotic to be discovered was penicillin in 1928 by Alexander Fleming - he noticed that some bacteria he had left on a petri dish had been killed by penicillin mold.

Monoclonal Antibodies

 * Monoclonal antibodies are extremely useful as they can be used to target specific cells and chemicals

Extracting? Monoclonal Antibodies

 * 1) Inject an animal (usually a mouse) with the antigen of the cell/chemical you want to specifically target
 * 2) The mouse's immune system will react to the antibody with the lymphocytes creating antibodies to combat the antigen
 * 3) Extract the B-lymphocytes created by the mouse (this kills the mouse)
 * 4) Lymphocytes do not grow well/survive in conditions outside the body, to fix this the lymphocyte is fused with fast growing tumor cells - a hybridoma
 * 5) The hybridoma then divides really quickly producing many monoclonal antibodies (named so as they are all cloned from the same cell)

Uses of monoclonal antibodies

 * Testing levels of hormones - pregnancy tests
 * Treating cancer, Monoclonal antibodies can be targeted at specific cells reducing damage to the rest of the body from radiation
 * Cancer cells can also be targeted to encourage white blood cells to attack the cancer cells
 * Location and identifying specific molecules in a cell or tissue

Advantages

 * Cancer treatment
 * Can target specific cells, reducing side effects

Disadvantages

 * Can still cause some side effects
 * Ethical objections to using animals