Diseases Flashcards
Histamine
A chemical produced by the mast cells that causes inflammation, runny nose and itchy throat.
Infectious disease
A disease that can be spread by physical contact
Interferon
A chemical released to inactivate a virus.
Antiseptic
Used on (only) the human body to prevent further growth of microbes.
Disinfectant
Destroys and kills microbes on non living objects. Eg. Bleach
Binary fission
The cell copies it’s DNA then splits into 2 separate cells - bacteria
An example of a prion
Mad Cow Disease
An example of a virus
Influenza
An example of bacteria
Cholera
Phagocytosis
The process of white blood cells (phagocytes) engulfing and destroying foreign matter in the body.
An example of a fungi
Athletes foot
Third line of defence specific/non-specific?
A specific response to each pathogen.
What are 3 examples of the first line of defence
Tears, intact skin, saliva, mucus, sweat, stomach acid.
Pathogens in the 3rd line of defence have what on them?
They have different antigens on their cell surfaces. So the white blood cells produce types of antibodies but only some can attach to the antigen.
How can the clumping together of antibodies when they attach to antigens destroy the pathogens?
It rips them apart and attracts phagocytes to come and engulf them.
Interferon
Chemicals released by infected cells to signal and warn neighbouring cells that its under attack by pathogens and attracts phagocytes
Fevers
Increase blood flow and body temp - faster flowing blood allows phagocytes to reach the infected area faster, interferons are more effective and under the high temperature the pathogens are less effective.
Why do we take Antihistamine tablets?
To take away the effect of the histamine that the body produces. To remove the symptoms caused by the body mistaking harmless substances like pollen grains for harmful pathogens. This is an allergic reaction.
An example of an antigen
Bacteria and other allergens such as pollen.
What are 2 aseptic techniques?
Wiping the bench before the experiment.
Using a Bunsen burner to clean the air around the agar plate and to remove bacteria - flame sterilisation
Having a different person turn the tap off and on during an experiment
Tape/seal plates
What is the inflammatory response?
A general response to an infection (2nd line of defence).
What is the smallest type of microbe?
Virus
How do prions reproduce?
Cells containing prions burst releasing more infections prions to infect other cells
How do bacteria reproduce?
Binary fission
How do viruses reproduce?
By infecting another host cell
How do fungi reproduce?
When they have absorbed enough food they can reproduce, they do this by producing spore cases full of spores ready to be released.
What do spore cases do?
Protect and grow the spores inside until they are ready, which they then burst out and fly away.
What is the purpose of the spores?
To spread more fungi to other food sources - their way of reproducing.
Are viruses considered living or non living?
Both
Why are viruses considered both living and non living?
They are considered to be non living because they cannot reproduce alone, they need a host and they are not made up of cells. However they are considered living because they have their own DNA.
Where can pathogens enter the body?
Eyes, mouth, skin, genitals, ears, nose and cuts in skin.
How are diseases transmitted?
Transmission by vectors, contact, air, sexual contact and water.
What is production by viruses called?
Lytic cycle
How does the lytic cycle work?
The virus attaches its self to a cell.
It pushes its DNA to the nucleus in the cell.
The DNA now gets photocopied by the nucleus.
There is now to many viruses in the cell so it explodes releasing them.
Why are agar plates turned upside down in the incubator?
Because its easier for the bacteria to grow, and condensation forms on the top lid of the plates and if the bacteria was on the bottom plate, the condensation droplets would fall on the bacteria disturbing its growth (spreading the colonies)
How do you label an agar plate?
You label an agar plate on the same side as the bacteria is growing on so incase you loose the lid then you still have the bacteria and you know what stage it is at.
How is antibody production different between the first and second exposure to a pathogen?
2nd = faster, larger and longer. Antibody production is a lot slower and less amount during the initial exposure than it is on the second exposure. This is because after the first exposure some white blood cells stay in the body, these are known as memory cells and they make the second reaction the the exposure a lot faster because they know what type of antibodies need producing to destroy the specific antigens.
What is herd immunity?
When most of the population is vaccinated against a particular disease therefore there are fewer host that can contract the disease and then be spread to others who are unvaccinated.
Is algae a pathogen?
No
What causes athletes foot?
Fungus
How is the flu spread?
Droplets when humans cough and sneeze
Antigen
A chemical on the surface of a pathogen that is recognised as foreign to the body.
Antibodies
Proteins that destroy pathogens
What are the types of vaccinations you can get?
Live but weakens pathogens, dead pathogens or partial fragment that still have the antigens.
What could a better vaccination be?
Live pathogens in a weakened form that can still reproduce. This results in a good immune response and can provide life long immunity I within 1-2 doses. Dead pathogens result in a weaker immune response and would require several doses.
How are the dead pathogens killed?
Radiation, heat or chemicals.
How does a vaccination work?
Memory cells are produced which then remain in the body to produce antibodies if their is a second infection.
An example of the second line of defence
White blood cells (phagocytes), inflammation and fever, interferon and histamine
What is a zone of inhibition?
The clear region around the anti microbial disc that has no microbe growth
Phagocytes
Certain types of white blood cells that circulate in the bloodstream waiting to engulf and destroy pathogens.
Which is stronger antiseptic or disinfectant?
Disinfectant
Eukaryotes
Have a cell nucleus
Prokaryotes
Have NO cell nucleus
How can we prevent the transmission of diseases?
Washing our hands regularly, covering our nose and mouth when sneezing and not sharing our water bottles
What’s an example of an antiseptic?
Betadine
What’s an example of a disinfectant?
Bleach
Why aren’t disinfectants used on the human body?
Because they are too harsh on the human skin.
What diseases can be spread via air?
Flu - sneezing
Pathogen
A disease causing agent
Is a bigger zone of inhibition better than a smaller one?
Yes because it means its killed more bacteria
What is the bacterial lawn?
The area around the zone of inhibition that has bacteria coveting it.
What are some controlled variables of the experiment?
The amount of bacteria on the plate
The temp of the incubator
The time in the incubator
What was the independent variable of the prac?
The type of antiseptic
What was the dependent variable in the prac?
Measuring the effectiveness of the antiseptic by measuring its zone of inhibition.
What is a colony?
A group of microbes (millions)
Why are viruses and prions nether prokaryotic or eukaryotic cells?
Because they are not cells.
Which pathogens are living?
Bacteria, fungi, protist and virus is living and non living
Which pathogens are cellular?
Bacteria, fungi, protist.
What does bacteria consist of?
A single cell
What does a virus consist of?
DNA within a protein coats
What does a fungi consist of?
Many cells (microscopic)
What do prions consist of?
Abnormal protein
What do protists consist of?
Called organisms
Which cells are prokaryotic? And which are eukaryotic?1
Bacteria is prokaryotic
Fungi and protists are eukaryotic
What pathogens have genetic material?
Bacteria, virus, fungi and protists.
Which pathogens have a cell wall?
Bacteria and fungi.
What is an example of a protist disease?
Malaria
An example of a protist is?
Malaria
What does a prion reproduce?
A mis-folded protein bumps into a normal protein, causing it to mis-fold
What is experimental control?
The agar plate that is uncontaminated, base line of the experiment.
Memory cells
White blood cells that form into memory cell after the first exposure to a disease, causing the second exposure to be a faster reaction. They remember a previous antigen and can produce antibodies quickly if the same antigen enters the body again.
Why are agar plates sealed?
To prevent contamination and spread of bacteria
What is an example of a 3rd line of defence?
Antibodies, antigens antihistamines.
