2.8 Disease, Defence and treatment (new) Flashcards
What is the function of a CELL WALL?
Protects + maintains shape
What is the function of a CELL MEMBRANE?
Controls substances entering and leaving the cell
What is the function of CYSTOPLASM?
Chemical reactions take place here
What is the function of a CHROMOSOME?
Contains DNA
What is the function of a SLIME CAPSULE?
Prevent bacteria drying out / Allows bacteria to stick together
What is the function of a FLAGELLA?
Allows movement
What is the function of PLASMID?
Small ring of DNA
What MICRO - Organisms cause disease?
Pathogens
Two examples of harmless bacteria?
- bacteria is in yogurt
- yeast in wine / beer
Four examples of pathogens
- bacteria , virus, protists, fungi
What is the causative agent of AIDS?
H.I.V (human immunodeficiency virus)
How does AIDS affect a person?
- Infects lymphocytes
- leads to a lack of immunity to other infections
How can AIDS be prevented?
Condom or disposable gloves
What is the causative agent of Chlamydia?
Chlamydia trachmatis (bacteria)
How does chlamydia affect an infected person
- infertility
- conjunctivitis
- lung problems in babies
How can Chlamydia be prevented?
By using condoms
What is the causative agent of Malaria?
Plasmodium (protist)
How does Malaria affect a person?
- destroys red blood cells
- causing fever
How do you prevent the spread of Malaria?
- killing mosquitos
- vaccines
How does the body defence itself from disease?
- skin forming a barrier against micro-organisms
- blood clots to seal wounds
- phagocytes IN THE BLOOD ingesting micro-organisms
- lymphocytes producing antibodies and antitoxins
What is an antigen?
- They are Protein molecules on cell membranes
How do LYMPHOCYTES kill microbes?
- A lymphocytes recognises the antigen of an invading organism
- The antigen on the foreign cell CAUSES lymphocyte to MULTIPLY into clone cells
- then they SECRETE a lot of antibodies SPECIFIC to the antigen into the BLOODSTREAM
- The antibodies attach to the antigens on the microbes
- kill them for them or allow them to be engulfed by pathogens.
What is the function of antibodies?
- the antibodies attach to the antigens on the microbes
- to KILL them or allow them to be engulfed by phagocytes
How does a vaccine produce memory cells?
the vaccine causes the IMMUNE SYSTEM to produce COMPLEMANTARY antibodies
- The antibodies target the antigen and ATTACH THEMSELVES to it in order to create memory cells.
- These will quickly respond to the antigen if it is encountered again
What does a vaccine contain?
- contains antigens derived from a diseased causing organism
How do you have immunity after a vaccine?
- (After an antigen is encountered) memory cells REMAIN in the body
- Produced QUICKLY , LARGER numbers of antibodies if the same antigen is encountered again
- (hopefully destroying microbes BEFORE SYMPTOMS are felt) THIS IS IMMUNITY
How were antibiotics ( Inc. Penicillin) produced?
- produced by living organisms ( fungi)
How were antibiotics ( Inc. Penicillin) produced?
- produced by living organisms ( fungi)
How do antibiotics cure bacterial infections?
- by KILLING bacteria or preventing their growth
How do some bacteria (MRSA) become resistant to antibiotics?
over use of antibiotics
How do you control MRSA?
- doctors prescribe antibiotics APPROPRIATELY
- patients should always complete the full course of antibiotics
- the agricultural use of antibiotics should be restricted
How can you make sure new drugs are safe?
By testing EXTINSIVELY, at a LARGE SCALE and RIGUROUSLY.
What do all drugs have?
Side effects
3 Arguments FOR animal testing?
- helps researchers to find drugs and treatments
- Improves human health
- helps ensure safety of drugs
3 Arguments AGAINST animal testing?
- Animals are killed or kept in captivity
- it is very expensive
- some substances tested may never be used for anything useful
What is the process of developing new medicines?
- tested using computer models and skin cells grown using human stem cells in the laboratory.
- tested on animals
- tested on healthy volunteers to check that they are safe.
What are 4 uses of monoclonal antibodies?
• diagnosis of diseases including Chlamydia and HIV
• tissue typing for transplants
• supporting chemotherapy for cancers
- Pregnancy testing
How are MONOCLONAL antibodies produced?
1-An antigen is injected into a mouse.
2-The mouse NATURALLY produces lymphocytes, which produce antibodies SPECIFIC to the antigen.
3- Spleen cells are fused with human cancerous white blood cells (MYELOMA CELLS) to form hybridoma cells which DIVIDE INDEFINITELY.
5-These hybridoma cells DIVIDE and produce MILLIONS of monoclonal antibodies SPECIFIC to the original antigen.
