Science 🧪🧬🔬

• Microorganisms


  Are very tiny living things that usually can only be seen using a microscope.
• A colony of microorganisms


  is a large number of bacteria or fungi that is visible without a microscope.
• Microorganisms include


  bacteria, viruses & fungi
• Pathogens


  Are microorganism (viruses bacteria and fungi) that cause disease
• Viruses


  Have a coat made from fat, inside this coat is genetic material, this material is either DNA or RNA, viruses never have both DNA & RNA.
• human diseases caused by viruses


  Colds, influenza, chickenpox, mumps, measles, German measles (rubella), hepatitis, AIDS, COVID 19.
• Covid 19


  Is a disease caused by a type of coronavirus, which are a particular family of viruses, Covid 19 is caused by a virus called SARS-CoV-2.
• A pandemic


  Is when a disease occurs over a wide geographic area. It affects an exceptionally high proportion of the population.
• Immunity


  Is the body's ability to fight infection.
• Antibiotics


  Are medicines that are used to treat infections caused by bacteria and some other pathogens.
• Vaccination


  Is when a harmless version of a disease is introduced to a person. This is done to simulate the production of antibodies & white blood cells against the disease.
• Viruses can only function


  Inside a living organisms
• Viruses can only reproduce


  Inside a cell
• The cell that becomes occupied by the virus is called

  The host cell
• When a virus enters a


  Host cell it uses the resources (food, enzymes etc.) of the cell to reproduce
• Immunity Properties


  Our immune system constantly defends against diseases. If it's too slow, infections can be fatal. In a healthy immune system, viruses trigger alarms, prompting the production of antibodies that neutralize them. White blood cells then engulf the virus. This process is similar for bacterial infections.
• Viruses are not affected by


  Antibiotics
• Ethical questions for vacation


  How much trialling using animals needs to be done before human trials, who will be used the trials, how many people need to be tested before a decision is made about the safety of the vaccine, can the government make vaccination compulsory for all.
• The rules and regulations around the development of vaccines

  1: exploration stage. 2: pre clinical development. 3: clinical trials.
• Human Clinical Trials


  1: v is tested in 20-100 healthy adults. 2: v is tested on hundreds of volunteers who come from different geographic areas & of different ages genders etc. 3: v is tested on thousands of volunteers
• Diseases caused by bacteria

  Cholera, tetanus, tuberculosis, dental decay, step throat, food poisoning.
• good bacteria


  Decomposers (break down dead organic matter), help to recycle Carbon & nitrogen in their cycles, used to make antibiotics, used in genetic engineering, play a vital role in their activities in our gut.
• Mutualism


  Is when two organisms live in close association & both of them benefit from the arrangement.
• Benefits to mutualistic bacteria in the gut


  Help digest some foods, produce vitamin B(for energy) & vitamin K (for clotting blood), prevent harmful bacteria from surviving in the gut, boast our immune system by keeping bad bacteria under control.
• Biotechnology


  Is using living organisms to produce a useful product.
• Fungi are


  Along with bacteria, are decomposers that break down organic matter to substances such as carbon & nitrogen compounds.
• Carbon & nitrogen compounds are reused by living organisms through

  Photosynthesis & nitrates from the soil
• Fungi that cause minor health problems for humans

  Athletes foot, ringworm
• Fungi are important for human health


  Provide powerful medicines (eg control cholesterol (statins)), provide us with immunosuppressant medications which prevent transplant patients from rejecting organs such as livers, heart and kidneys, penicillin & other antibiotics are based on natural chemicals produced by fungi.
• How do bacteria become resistant to antibiotics?


  Bacteria reproduce every 20 minutes, reproduction provides the opportunity for mutation to occur in DNA eg. It may develop enzymes that destroy a particular antibiotic, or a mutation can cause an extra thick cell membrane to be made, which prevents the antibiotic from getting into the bacteria
• Misuse of antibiotics:


  Overuse of a certain antibiotic, not finishing a corse of antibiotics, bacteria that become resistant to antibiotics become known as 'super bugs' eg MRSA
• Food spoilage & how to prevent it

  Refrigeration, freezing, pickling, salting & syrup, dying, pasteurising, canning
• Photosynthesis


  Is the process by which plants make their own food using light
• word equation


  Chlorophyll

  Carbon dioxide + water——————————--> glucose + oxygen

  Sunlight
• Photosynthesis chemical equation


  Chlorophyll

  6CO2 + 6H2O ————------> C6H12O6 + 6O2

  Sunlight
• How plants photosynthesise


  Take in Carbon dioxide from the water through thinly pores called stomata (stoma), taking in water from the soil by their roots, sunlight is absorbed by chloroplasts in the cells, chlorophyll allows carbon and water to combine to form glucose, the energy for this reaction come from sunlight trapped by the chlorophyll, oxygen is given off as a waste product.
• As a chemical process


  Involves a number of steps, and new substances are formed
• As a biological process


  Occurs in the chloroplasts of living cells where enzymes that are essential to the process are present, it occurs in living cells & involves a number of steps
• Carbon cycle


  The constant cycling of carbon atoms.
• Factors affecting photosynthesis


  light intensity, carbon dioxide concentration and temperature