2.7 Microorganisms and Applications Flashcards
How frequently do bacteria duplicate?
Every 20 minutes
How do we grow bacteria?
We grow it in a nutrient rich broth at 30°C exactly
Why is the nutrient rich broth kept at 30°C?
It provides a stead rate of reproduction and reduces the chances of growing pathogens (bacteria) that are dangerous to humans (who have a temperature of 37°C).
What temperature range do bacteria grow in?
5°C-60°C
What are the 5 main safety measures taken in aseptic technique?
- Keep a general sterile environment
- Flame the loop before and after putting it in the culture bottle and petri dish.
- Flame the rim of the culture bottle after use
- Keep the lid on the petri dish as much as possible
- Make sure the dish is not airtight become incubating (which causes an anaerobic environment).
Why do we make sure the petri dish is not airtight before incubation?
To prevent the growth of anaerobic bacteria that are especially dangerous to humans.
How do we add bacteria to the petri dish?
Through a streaking pattern that slowly reduces the bacteria in each line
In the end you are left with single colonies of bacteria.
What is a pathogen?
An organism or microorganism that causes disease.
What are the 5 main types of pathogens?
Viruses Bacteria Fungi Worms Protozoa (Single cell organisms with a nucleolus)
What is the structure of a virus?
- RNA Genome (in the centre)
- H and N spikes (Attaches to cells)
- Capsid (which contains the RNA)
- Envelope (around the virus)
What is the structure of a bacteria?
- Pili (Attachment)
- Bacteria Flagellum (For movement)
- Capsule (Outside- for protections)
- Cell Wall (Medium)
- Plasma Membrane (Inner)
- Cytoplasm
- Ribosomes (small granules)
- Plasmids (Larger that ribosomes)
- Nucleoid (Loose bundle of DNA)
What are the 5 dangerous pathogens to remember, how are they transmitted and what is there scientific name?
Cholera (Bacteria)- Contaminated water- Vibrio cholerae
Spanish Flu (Virus)- Airborne droplets from coughs and sneezes- Influenza
HIV (Human Immunodeficiency Virus) causes AIDS (Acquired Immune Deficiency Syndrome)- Bodily fluids (sex) and contaminated needles (drugs)
Malaria (Parasite)- Female mosquitos- Plasmodium spp
Chlamydia (Bacteria)- Bodily fluids- Chlamydia trachomatis
What are the two types of white blood cells?
Phagocytes
Lymphocytes
What is the job of a phagocyte?
To ingest microorganisms and break them down.
They attack any foreign cell.
*Phagocytes fight
What is the job of a Lymphocyte?
To produce antibodies that destroy/ weaken microorganisms and anti-toxins which neutralise poisons produced by pathogens.
What are antigens and their purpose?
They are chemical ‘markers’ on the surface of cells that help the body tell the difference between our own body cells and invading microorganisms.
What are antibodies and their purpose?
They are produced by the lymphocytes and are produced to attach to antigens of a pathogen and clump them together (Which makes it easy for phagocytes to consume).
What are memory cells?
White blood cells that remember to antigens of a previous pathogen.
What are monoclonal antibodies? (mAbs)
They are identical copies of one type of antibody that binds to a specific antigen.
What is the process of creating monoclonal antibodies?
1) A mouse is vaccinated with a specific antigen which starts the formation of anti-bodies
2) Spleen Cells, which produce lymphocytes are taken from the mouse in an operation.
3) Spleen Cells are fused with human cancerous white blood cells called myeloma cells to form hybridoma cells.
4) The hybridoma cells with divide rapidly and produce millions of monoclonal antibodies.
What is the name given to cancerous human white blood cells and why are they used in the creation of monoclonal antibodies?
Myeloma cells are used as they dived very quickly, far quicker than spleen cells. When they are fused with spleen cells, they create a cells that divides far quicker and still produces the desired anti-body.
What is the name given to the cell formed by the fusion of mouse spleen cells and myeloma?
Hybridoma cells
What is aseptic technique?
A way of dealing with potentially hazardous pathogens with as little contamination as possible.
What are the uses for monoclonal antibodies?
- Pregnancy tests- monoclonal antibodies bind to the hormone HCG, sparking a colour change.
- Cancer diagnostics- Some mAbs have a dye attached to them and will glow under UV when attached to the antigens of a cancerous cell
- Cancer Treatment- Some mAbs have drugs attached to them. And others can alert the immune system to the cancer cells presence which destroys it.
What are the limitations of mAbs?
- They are expensive to produce
- Some people are allergic to the mice used
- There can be unwanted side effects due to the complicated nature of the human body
- There are ethical issues such as the use of mice and the operations on them
What are the 3 pre-medical steps in drug testing?
1) Testing on cells/ tissue in a lab (pre-clinical)
2) Testing on animals (pre-clinical)
3) Testing on healthy human volunteers (clinical)
What are the 6 steps for investigating the effects of antibiotics on bacteria growth?
1) Cut 4 wells in an agar fully infected with a bacteria (using a cork borer).
2) Label wells 1-3 under the petri dish (using a market)
3) Fill wells 1-3 with different anti-biotics (hand sanitizer) and the 4th with liquid soup
4) Seal the petri dish, leaving an airgap
5) Incubate the dish for several day at 30°C
6) Examine the results and measure the clear zones around the different wells to determine the how effective each anti-biotic is.
Who discovered Penicillin?
Alexander Fleming
Who created vaccines?
Edward Jenner
What are the types of blood?
A
B
AB
O- works with any, no antigen
Conditions for fermentation?
23-28°C
Oxygen
6.5 pH
Aseptic- only one micro-organism
What is the binomial name for penicillin
Penicillium (italics)
