Microbiology intro Flashcards
When is a person in good health?
- Some might say when the body and mind are fully balanced
- Others may describe as the body is working as it normally does (Homeostasis)
What is healthy?
Maintenance of internal stability whilst in changing environment conditions (dynamic, changing of internal conditions to survive external challenges
What is remaining healthy also defined as?
Maintaining homeostasis
How do we maintain our homeostasis?
▪ Appropriate level of physical activity
▪ Adequate nutrition (energy and components)
▪ Good quality sleep
▪ Mental stimulation
—Socialization
—Active brain
—Emotional
▪ Stress management
—Environmental, Social, Biological
▪ Strong Immune System
—Natural Defences
—Quick response
What is our metabolic homeostasis and how do we maintain it?
Every living organism depends on maintaining complex metabolic chemical reactions:
* Regulating blood sugar, temperature, Acid base balance
* Sensor to detect changes
* Effector mechanism
* Negative feedback mechanisms to support regulation.
What is becoming sick also known as?
A disturbance in homeostasis
What can cause a disturbance in homeostasis (becoming sick)?
▪ From outside the body (Exogenous, having an external cause or origin) - pathogens, environment, diet
▪ From inside the body (Endogenous,having an internal cause or origin) - lifestyle choices, organ & system failure, genetics
▪ Chronic – Long lasting
▪ Acute – Short term
▪ Mild or severe sickness
Define exogenous.
having an external cause or origin
ie: pathogens, environment, diet.
Define endogenous.
having an internal cause or origin.
ie: lifestyle choices, organ and system failure, genetics.
What is a disease?
A disorder of structure or function in an organism especially one that produces specific symptoms or that affects a specific location and is not simply a direct result of physical injury.
Define pathogen.
A disease causing microorganism.
What are microorganisms?
A tiny unseen organism not visible without manification.
It is a broard term used to group many different organisms together such as viruses, bacteria, fungi, protozoa, algae, prions.
They can also be classified in different domains of life as prokaryotes and eukaryotes.
How many microorganisms are in humans?
There are the same amount of microorganisms in our own bodies than we have actual cells, if not more.
What are microorganisms essential for?
These are essential for all areas of our life such as:
- Health – digestion, help produce vitamins in the gut like K and folic acid, outcompete dangerous bacteria, genetic engineering.
- Food and drink – cheese, yoghurt, beer.
- Medicine – research, antibiotics, insulin production (in bacteria)
- Environment – water waste systems, recycling dead animal and plants releasing nutrients.
What is Fecal microbiota transplantation (FMT)?
patient is given a solution of fecal matter from a healthy donor – To change microbial composition.
When is Fecal microbiota transplantation (FMT) used?
Used for recurrent c.difficule infection when treatment with antibiotics is iunsuccessful. Treatment of this infection using fmt has seen a >90% cure rate.
What are prokaryotic cells?
Cells with no defined nucleus and no membrane bound organelles (no mitochondria, lysosomes etc).
Includes all bacteria and possess a simpler structure than eukaryotic cells.
Function of plasma membrane in prokaryotic cells?
Plasma membrane separates the external environment from the internal cytoplasm. It creates an impermeable barrier to most molecules.
Function of cell wall in prokaryotic cells.
Cell wall provides strength and rigidity: but permeable to many small molecules.
What are the prokaryotic structure?
Nucleoid
Cell Wall
Plasma membrane
Capsule
Cytoplasm
Ribosomes
Flagellum
Fimbriae
Function of nucleoid in Prokaryotic structures?
Contains DNA and used for replication
Function of cell wall in Prokaryotic structures?
– Gives strength to the cell to stop it bursting due to differences of environmental conditions inside the cell and outside
Function of plasma membrane in Prokaryotic structures?
acts as a barrier controlling what enters and
leaves the cell
Function of capsule in Prokaryotic structures?
protection and helps keep bacteria together
Function of cytoplasm in Prokaryotic structures?
Liquid within cell holding nutrients etc
Function of ribosomes in Prokaryotic structures?
Free floating and helps with protein production
Function of Flagellum in Prokaryotic structures?
controls the movement of the cell
Function of Fimbriae in Prokaryotic structures?
help gram negative bacteria stick to each other
What are eukaryotic cells?
Unlike prokaryotes, eukaryotic cells contain extensive internal membranes that define a collection of subcellular structures – organelles
The cytoplasm also contains a network of fibres called the cytoskeleton, which give the cell strength and rigidity and also control movement within the cell
Include all plants and animals as well as many single celled organisms: algae, amoebae, fungi and moulds. (Eukaryotic – cells with a true nucleus)
How do plant cells differ from animal cells?
They are surrounded by a rigid cell wall for structure, support and rigidity.
Contain a large membrane bound vacuoule and chloroplasts.
DIfferences between prokaryotic organism and eukaryotic organisms?
Prokaryotes have no nucleus and no membrane bound organelles (no mitochondria, no lysosomes, etc).
Eukaryotes have cells which are organised into complex structures by internal membranes and a cytoskeleton. Have a nucleus.
Prokaryotes mostly single celled but some multicellular.
Eukaryotes more complex in structure and function than prokaryotic organisms.
Prokaryotes are the oldest forms of life. Older than eukaroytes.
What are viruses and how they work?
Viruses are obligate intracellular parasites – they are unable to metabolise, so hijack cellular machinery of prokaryotes or eukaryotes in order to reproduce.
What is the difference in surface area to volume ratio between prokaryotes and eukaryotes?
Prokaryotes have a larger surface area to volume ratio giving them a higher
metabolic rate, a higher growth rate and consequently a shorter generation time
compared to Eukaryotes.
Difference of dna between prokaryotes and eukaryotes?
Prokaryotes contain only a single loop
of stable chromosomal DNA, while eukaryote DNA is found on tightly bound
and organised chromosomes.
Difference of size between prokaryotes and eukaryotes?
Prokaryotes are usually much smaller than eukaryotic cells.
DIfference between location of processes between eukaryotic and prokaryotic cells?
In prokaryotes many processes occur across the cell membrane; rather than
within the cell.
WHat is the most fundamental difference between prokaryotes and eukaryotes?
The most fundamental difference is that eukaryotes do have “true” nuclei
containing their DNA, whereas the genetic material in prokaryotes is not
membrane-bound.
Where are bacteria found?
Found everywhere
What can bacteria do?
Many cause illness
Some cause spoilage of food
Some bacteria are essential such as skin flora and gut flora
Many are harmeless, many are mutualistic
How do bacteria reproduce?
They reproduce by binary fission.
What is binary fission also known as?
Prokaryotic fission
What kind of reproduction is binary fission ?
asexual reproduction
Describe the process of binary fission.
1) Cell elongates and DNA is replicated
2) Cell wall and plasma membrane begin to divide
3) Cross-wall forms completely around divided DNA
4) Cells separate
Define virus.
A virus is a simple microorganism consisting of either RNA or DNA surrounded by a coating of either protein and fat, or glycoprotein.
How does a virus work?
Virus needs to hijack another cell in order to reproduce (some viruses are referred to as a phage – eats bacteria, impairs fitness / lysis, e.g EBV)).
What are some viruses also referred to as?
as a phage cus they eat bacteria.
Compare the size of viruses to other microorganisms?
Very small when compared to other microorganisms
What does a virus replicate with?
other living organisms.
WHy do we get symptoms when we have a virus?
▪ The immune system will detect the virus and have a response to it.
▪ This immune response causes us to have symptoms for example those of the
common cold.
What are the major stages of a viruses life cycle?
attachment,
entry,
uncoating,
replication,
maturation,
and release
How dangerous are viral infections?
▪ Can be short lived infections
▪ Some viruses cause severe and permanent damage to body systems such as HIV.
Are fungi prokaryotes or eukaryotes?
They are eukaryotes so they have a defined nucleus and organelles
They are larger than porkaryotes such as bacteria.
What are the three types of fungi?
1) Moulds (filamentous) growth and multicellular structures
2) Yeasts (non-filamentous) and tend to be single celled
3) Mushrooms which produces spores.
Is fungi a bigger issue for plants or humans?
Major issue for plants rather than humans
Where is fungi used alot?
Extensively used in the food industry
What are protozoa?
Most are single-celled eukaryotes.
How do protozoans reproduce?
Not all reproduce by mitosis as with animal cells some do by binary fission like bacteria.
Where do protozoans live for part of their lives?
They tend to live at least part of their life cycle with the host bodies.
Examples of protozoan?
Examples: Giardia and malaria (genus Plasmodium).
What are algae?
Algae are eukaryotic organisms with nuclei.
They are photosynthesic organisms
Algae have many types of life cycles.
What is the size of algae?
They range in size from microscopic to up 60 metres in length (kelp)
Does not always fit with definition of microorganism
What are prions?
Misfolded proteins with the ability to transmit their misfolded shape onto normal variants of the same protein.
What do prions cause?
Cause neurodegenerative diseases in humans and many other animals.
Why are prions different to other microorganisms?
Different to other microorganism such as viruses, bacteria, fungi and parasites, as they all contain nucleic acids (DNA, RNA or both).
Why are prions overlooked by our immune system?
Because just a misshaped protein it is not recognised by our immune system so gets over looked
What are the two forms of transmission of prions?
1.genetically as a dominant trait
2. infection
Examples of prion disorders?
- Inherited – Familial Creutzfeldt-Jakob disease
- Infectious – BSE (bovine spongiform encephalopathy
