Biology KA1

how the body protects us from disease

immunity vaccinations: a small dosage of a disease is inserted into the body so that lymphocytes can be produced and clump together pathogens (lock and key) . then phagocytosis can take place before the disease spreads, so that if you got the disease, the immune system would destroy it before you even feel any symptoms Herd immunity: when a certain amount of people have a vaccination against a disease, this can prevent others from getting that disease who may not be able to get vaccinated because of age, illness or allergies. It is a 'protective barrier' which discontinues the spread of a disease. Each disease has an Ro=basic reproduction number. non-specific defence mechanisms These are parts of the body that act as barriers to prevent pathogens from entering our body. some include: nose hairs(mucus) mucus and ciliated cells on bronchi and trachea skin (barrier) tears(enzymes that 'kill' pathogens) stomach (acid that kills enzymes) Specific Defence Mechanisms phagocytosis

Lymphocytes and Phogocytes

Lymphocytes are made of protein and produce antitoxins and antibodies. When pathogens enter the body, the immune system sends out lymphocytes which produce antibodies that clump with complimentary pathogens.  Phagocytes ingest the clumped pathogens in a process called phagocytosis.  after this process has taken place, you are now immune to that particular disease

Functions andAntibiotics and Painkillers

these can help cure bacterial diseases, but not viral diseases Antibiotics can slow down or stop the growth of bacteria and are commonly known as medicines and in the form of penicillin and amoxicillin.  Antibiotics damage bacterial cells but don't damage the host cells. They can cure some diseases which previously wouldn't have been curable which widely affected the death rate.  different bacteria causes different diseases so a range of medicines are needed to cure each/a few specific ones.

Amylase Practicle

Amylase breaks down starch and produces glycose catalysts speed up the rate of a chemical reaction enzymes are catalysts and like all, can be used over and over again the active site is a special part in the enzyme where the substrate binds enzymes denature if the temperature isn't optimum which slows the rate of the reaction Practical Protein-is contained if burets solution is added and it turns purple fats-are contained if ethanol and water is added and it turns cloudy sugars-are contained if Benedict's solution is added and it turns orange (a little) or red (a lot) starch-is contained if iodine is added and it turns black: iodine in 2 drops each on a spotting tile put 3 test tubes in a water bath (2cm^3 starch solution, 2cm^3 amylase solution, 2cm^3 pH buffer) and heat to optimum temp (35 degrees) take out and mix drop into each tile, 30 secs apart and when solution stays orange, and no longer turning blue/black, starch is no longer present

What Affects Diffusion & Active Transport?

Diffusion is the moment of particles from an area of high concentration to low concentration no extra energy is needed for diffusion Factors steep gradient (concentration) hotter temperature large surface area smaller distance (thinner) Eg. bronchiole=oxygen and CO2 diffuse quickly as there is a large surface area in the bronchiole and there is only a 1cell thickness (short distance) Active transport is the movement of particles from an area of low to high concentration Affected by the concentration gradient and needs kinetic energy to travel. Eg. Root hair cell=nutrients go through the membrain from low to high (in the cell) so that the plant has enough nutrients to survive   

Heart and Blood Vessels

heart has 4 chambers, right atrium, left atrium, right ventricle and left ventricle (thick wall to put blood under high pressure) Aorta takes O (oxygenated) blood from left ventricle to cells around the body and returns as DO (de-oxygenated) blood through the vena cava into the right atrium. DO blood is then taken out out the pulmonary artery in the right ventricle to the lungs where it becomes O blood. it is brought back through the pulmonary veins and taken back to the left ventricle where the cycle repeats. Blood Vessels Artery= carry blood say from the heart, under high pressure. Has elastic fibres, a thick wall and a small lumen Capillaries= takes blood to each individual cell, where nutrients exchange. Has a very thin wall for diffusion Veins= takes blood back to the heart from the body and has valves to prevent back-flow. Has a thin wall  

CHD(Coronary Heart Disease)

disease that can cause heart attacks cholesterol builds up in the arteries and over time, can fully block the arteries stopping blood from coming to and from the heart One treatment are statins which is is a medicine. it can lower cholesterol and get rid of a build up of it in arteries Another treatment is a stent which is put in place in a gap in the artery. It is then blown up with a balloon which keeps it in place before popping it, so that the artery is kept open for blood to pass through. Heart bypass surgery is a final one and what happens is that an artery is attached to the beginning and end of the blocked one so that blood travels through there and doesn't get stuck in the blocked one, filled with cholesterol.