Module 3 Flashcards
What are the five major types of microbes
Viruses, bacteria, fungi, protists, algae
Edit major microbes
Explain what a virus does and what it is
These are the smallest and simplest biological entities. They are acellular, and the DNA/RNA is in a protein shell
A virus can’t do anything by itself, unless it meets a host cell. (Depends on host cell for replication/metabolism) (steals nutrients and utilises host cell machinery)
Many viruses cause disease in humans, animals and plants
Explain what a bacteria does and what it is
These are normally unicellular (prokaryotes). They are able to reproduce, independent of a host cell. They also have their own metabolism
They can function as primary producers and decomposers
Explain what a fungi does and what it is
They are normally large complex cells(eukaryotes), however they could also be single-celled.
They have a membrane bound nucleus, and contain complex organelles like mitochondria, golgi apparatus
Fungi are heterotrophs so they would have to absorb nutrients from external sources. And they could reproduce sexually or asexually
Fungi are primarily decomposers, breaking down dead organic material and recycling nutrients in ecosystems. Some fungi form symbiotic relationships with plants, helping them absorb nutrients
Explain what a protist does and what it is
Protists are a diverse group of mostly single-celled eukaryotic organisms, which means they have a nucleus and other organelles enclosed within membranes. Protists don’t fit neatly into other kingdoms like plants, animals, or fungi, so they are often considered a “catch-all” group for eukaryotes that don’t fall into these categories.
They can do various functions like decompose and photosynthesise, however many are also predators.
Explain what an algae does and what it is
Algae are a diverse group of primarily aquatic, photosynthetic organisms. They are similar to plants in that they contain chlorophyll and produce their own food through photosynthesis, but they lack many structural features of land plants, like roots, stems, and leaves. Algae are found in a wide range of environments, including freshwater, saltwater, damp soil, and even on rocks or in snow.
They can reproduce sexually or asexually
What are some key inventions and ideas in microbiology
Microscopes, agar plates, spontaneous generation, germ theory, Koch’s postulates, Penicillin
Who came up with the term ‘cells’
Robert Hooke came up with it in his book called “micrographia”
Who discovered bacteria and protists
Antonie van Leeuwenhoek in 1684 by using powerful microscopes (300x)
What did Louis Pasteur contribute to the field of microbiology
Developed vaccines
Developed the process of pasterusation
Fermentation
Disproved spontaneous generation
What was spontaneous generation
The belief that live organisms can be generated from non-living organisms, without the involvement of pre-existing life
I.e. believed that maggots came from rotting flesh (just like that - no other factor)
What was the ‘proof’ for spontaneous generation
John needham used broth that was boiled then sealed in flasks. Microorganisms then appeared in the broth of hay water, suggesting that life could spotaneously arise from broths
How was spontaneous generation challenged by Pasteur and Redi
Redi showed that maggots on meat came from fly eggs - not the meat itself
Pasteur conducted an experiment where he used a swan bottled flask to see if microorganisms could grow. Basically this swan bottled flask acted to stop bacteria from coming in from the air - provides air to the liquid, but prevents bacteria from getting in as they get stuck in the swan bottle neck. However, when the curved neck was removed, air could enter and bring microorganisms which grow in broth. This suggests that microbes in air was responsible for contamination
What was the germ theory of disease
Believed that microbes were the causative agents of disease (previously believed that it was miasma - bad air which caused disease)
germs are transmitted from one individual to another from contaminated surfaces etc
Koch’s postulates were an important aspect to this theory
What were Koch’s postulates for disease
An organism that causes a disease must:
Be able to be found in all organisms which have the disease
Be able to be isolated
The isolated organism should be able to be reintroduced to another organism and cause disease (i.e. produce disease in experimentally infected host)
Be reisolated from the experimentally infected host
What was penicillin
It was discovered by Alexander Fleming who found a random fungi (penicillium) who’s juices were able to kill bacteria. –> as well as many bacterias
Penicillin was mass produced by Florens and Chain from 1935-1945, which helped with WW2
How many lives did penicillin save
100 000 in WW2, and over 200 million lives since then
What else was Robert Koch well known for in his contributions to microbiology
He develped staining methods for microscopy
Use of solid growth medium (agar) which allowed for isolating colonies (which wasn’t achievable before)
We now use agar in everyday life
What are normal flora
These are normal microbes that live in us and on us, and dont normally cause disease for us
They are normally acquired at birth, from diet and environment
WHat are the benefits of a microbiota
Primes immune system
Improves digestion
Nutritional benefits
Competes with pathogens (for consumption of nutrients, which is good)
What are the drawbacks of microbiota
Potentially causing disease
Weakened immune system
Wrong location of microbiota could have negative impacts
Changes in conditions could cause microbiota to have a negative impact
What are pathogens ? What are the two types
These are disease causing microorganisms. The two types are obligate and opportunistic
What are obligate pathogens
These cause disease no matter the situation they are in (always cause disease)
What are opportunistic pathogens
These cause disease when optimal conditions arise. (i.e. under specific conditions)
What are some conditions which might be optimal for opportunistic pathogens
Temperature
Weakened immune system
Wrong location
Large numbers
Antiobiotic resistance
What is the concept of one health
Focusses on looking at health from a bigger picture
We need to consider animals, plants and environment when trying to manage human viruses
In other words, its encouraging us to consider the environmental origins of disease as well
Influence of urbanisation, globalisation, climate change etc.
Describe a major problematic infectious disease
Mycobacterium tuberculosis
This bacterium causes tuberculosis. Spreads person-to-person by airbone droplets such as coughing. It infects the lungs, causing cough, chest pain, weight loss and potentially death
Could be latent for many years, and approx 1/3 of the worlds population is infected
There is a large infection rate in Africa and SEA due to lack of medical facilities
What are the steps involved in food production
Production (i.e. initial natural production of food such as animals, plants etc) –> processing (actually processing the natural produce into something edible)–> distribution –> retail/restaurant –> Consumer
Explain how microbes could benefit the production stage
Rumen microbes help cows digest grass
Some fungi act as symbiotes to boost plant growth
Some microbes are useful for maintaining soil health (recycling wastes into nutrients)
Explain how microbes could benefit the processing stage
Microbes are needed for some processing, especially with the need for fermentation
Explain how microbes could benefit the retail/restaurant stage
Some microbes act as food sources in retail such as some fungi (mushrooms), algae
Explain how microbes could benefit the consumer stage
Boosting consumer/peoples gut microbiomes
Explain how microbes could have a detrimental impact on the production stage
Pathogens could kill animals and plants are cause diseases which could be passed on to humans
Post harvest contamination can ruin crops
irrigation water could be contaminated with pathogens
Explain how microbes could have a detrimental impact on the processing stage
Factories could be contaminated with microbes, having a negative impact
Explain how microbes could have a detrimental impact on the distribution stage
Refrigeration needed to stop microbial growth
Explain how microbes could have a detrimental impact on the retail/restaurant stage
Poor hygiene can result in microbial growth on food
Explain how microbes could have a detrimental impact on the consumer stage
Poor gut microbiota causes poor health (controlled by what we eat)
How can microbes enhance food production in plants
They can help fix nitrogen (which is necessary to maintain good health)
Kill animal and plant pathogens
Break down organic wastes into inorganic nutrients
Breaks down toxins e.g. pesticides
How can microbes enhance food production in animals
The cellulose in plants is thick and thus hard to digest. However, rumen microbes are able to help with the digestion here, to turn cellulose into sugars and organic acids
What is mutualism
Both organisms benefit
What are examples of useful mutualistic relationships
Mycorrhizal fungi, rhizobium bacteria
How can mycorrhizal fungi have a beneficial impact
Mycorrhizal fungi are in most plants roots , and they help enhance water and inorganic nutrient uptake, and receive sugars from the plants in return
how can rhizobium bacteria have a beneficial impact
Rhizobium bacteria are in legume roots
They help fix nitrogen (i.e. turn N2 in air to nitrogen (ammonia) that the plants can use). They also receive sugars in return
