2.1 Different Types of Disease Flashcards
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What is Disease?
A disorder of structure or function of an organism that is a direct consequence of a change or disruption of function of a biological system at a molecular and cellular level. Can be grouped into infectious and non-infectious.
Infectious v Noninfectious
Infectious diseases are caused by harmful organisms that get into your body from the outside, like viruses and bacteria. For example the flu, measles, HIV, strep throat, COVID-19 and salmonella are all examples of infectious disease. Noninfectious diseases aren’t caused by outside organisms, but by genetics, anatomical differences, getting older and the environment you live in. Cancer, diabetes, congestive heart failure and Alzheimer’s disease are all examples of noninfectious diseases.
Pathogens
- Diseases are transmitted from organism to organism via pathogens
- pathogens have the ability to destroy cellls or release toxins
- Six maintypes:
- Bacteira
- Fungi
- Protists
- Viruses
- Parasites
- Prions
Bacteria
- Small single-celled (unicellular) organisms
- Bacteria are vital to the planets ecosystems, with the ability to survive extreme conditions
- The human body is full of bacteria
- For example: Pneumonia, food poisoning, cholera, Wound infections
- Good bacteria: bacteria in the gut, yoghurt, kombucha, milk, cheese
Fungi
- Microorganisms, they are eukaryotes and have cells
- They are heterotrophs: get energy to live from feeding on organic matter of other organisms
- Reproduce through spores
- For example: Ringworm, Athletes foot
Protists
- Group of mostly unicellular eukaryotic organisms, belonging to the Kingdom Protista
- Heterotrophs: asorb nutrients from hosts
- Can be found in most terrestrial, aquatic, and marine habitats as free-living forms and as parasites of other protists, of fungi, and of plants and animals.
Viruses
- Infectious microbe of nucleic acid (DNA or RNA) surrounded by a protein coat
- Viruses are not made out of cells, they can’t keep themselves in a stable state, they don’t grow, and they can’t make their own energy. Therefore, Viruses cannot replicate alone, must infect and attach to host cells, virus takes over host cells, using components of the cell to make hundreds or thousands of copies
- Host cell will eventually burst and release even more virus particles in host body
- For example: influenza, common cold, chicken pox, ebola, AIDS
Parasitic Worms
- Organisms that live in and feed on food in the hosts intestines for nutrients
- Worms lack digestive systems, but have a developed reproductive system to lay many eggs that will pass through faeces
- For example: tapeworm and thread worm
Binary Fission
- asexual reproduction by a separation of the body into two new bodies.
- During binary fission, the DNA molecule divides and forms two DNA molecules. The cell then grows to create room for each molecule to move towards the opposite side of the bacterium. At the same time, the cell membrane divides to form 2 daughter cells. After division, the new cells grow and the process repeats itself.[2]
Viral replication
