Infection and response Flashcards
(44 cards)
what is a pathogen
disease-causing organisms
what are examples of pathogens(4)
viruses
bacteria
fungi
protisits
how do bacteria affect the human body?
bacteria produce toxins which damage our cells
how do viruses affect the body?
viruses enter our body cells and reproduce inside them destroying our cells and making them burst
3 main viral diseases
HIV- human immunodeficiency virus
TMV- tobacco mosaic disease
Measles
3 bacterial diseases
gonorrhea
salmonella
rose black spot
what are communicable diseases?
diseases that can be spread
how can pathogens be spread?(4)
airborne
direct contact
droplet infection
water
How is gonorrhea spread
via sexual contact
Why is it difficult to develop drugs to kill viruses?
Viruses are usually found within body cells, so it is hard to kill the virus without damaging the body’s tissues.
What are the steps of phagocytosis?
1 First, the phagocyte tracks down a pathogen and binds to it.
2 The phagocyte’s membrane will then surround the pathogen and engulf it.
3 Finally, enzymes inside the phagocyte break down the pathogen in order to destroy it.
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What are bacteria?
Bacteria are tiny unicellular (single cell) organisms that are found almost everywhere.
Can a particular type of antibiotic kill all types of bacteria?
No. Each antibiotic is specific to an individual type of bacteria, or specific to a group of bacteria.
How does vaccinating a large proportion of the population help the people who didn’t get vaccinated?
Widespread vaccination can result in herd immunity, which help prevent outbreaks of disease.
This means the disease is very unlikely to spread from an infected person to someone who is not vaccinated, because almost everyone else is vaccinated.
What are the symptoms of TMV?
It gives a distinctive ‘mosaic’ pattern of discolouration on the leaves which affects the growth of the plant due to lack of photosynthesis.
How does the skin act as a defence against pathogens?
1 It covers the body, physically preventing pathogens from entering.
2 It secretes oils and antimicrobial substances that kill pathogens.
Which organism did aspirin originate from?
Willow tree.
What does the drug ‘digitalis’ treat?
Heart failure
What does HIV stand for?
HIV stands for Human Immunodeficiency Virus.
This is because it affects humans, it weakens the immune system (immunodeficiency), and it is a virus.
What are the initial symptoms of HIV?
Flu like illness
Can an antibiotic kill viruses?
No they can only kill bacteria
Which body cells does HIV attack?
Immune cells - specifically, a type of white blood cell.
With reference to drug testing, what is a placebo?
A placebo is a substance or treatment that looks like the real treatment, but contains no active drug.
What is antibiotic resistance?
Occasionally, by random chance, bacteria evolve so that antibiotics no longer kill them. In these cases we say that the bacteria has developed ‘antibiotic resistance’.
