Monera/ Bacteria Flashcards
What kingdom does bacteria belong to?
Monera
What type of organism is a prokaryotic?
An organism that does not contain a distinct nucleus or membrane-bound organelle.
Bacteria can only be seen with a…
microscope
Is bacteria single-celled or multicellular?
single celled
Do bacteria reproduce sexually or asexually?
asexually
What is asexual reproduction?
Reproduction involving only one parent & the offspring are genetically identical to that parent.
What conditions can bacteria survive?
High/Low temperatures, High/low pH, Anaerobic conditions, High pressure.
What are the parts that are in every bacterium?
Cell wall, Cell membrane, Loop of DNA, Cytoplasm, Ribosome, Storage granule
What is the function of the cell wall?
Protection of the cell.
What is the function of the cell membrane?
Controls what goes in and out of the cell.
What does the loop of DNA contain?
Contains genes that control the cell.
What is the cytoplasm?
Clear, jelly-like component of the cell.
What is the function of ribosomes?
Site of protein synthesis.
What are the functions of cytoplasm?
Maintains the shape of the cell, Metabolism.
What does the storage granule do?
Stores water & nutrients.
What are the parts that are in some bacteria?
Capsule, Flagellum, Plasmid
What is the function of the capsule?
Further protection from harsh environments.
What is the function of the flagellum?
Allows movement.
What does the plasmid contain?
Contains extra genetic information.
How are bacteria classified?
By shape.
What are round bacteria found in?
Pairs, chains, and clusters.
Eg: Pneumonia & E. coli
What are rod bacteria examples?
Eg: Salmonella & Tetanus.
What are spherical bacteria examples?
Eg: Cholera & Syphilis.
What is the reproduction method of bacteria?
Asexual: binary fission.
What are the steps of binary fission?
A DNA strand in a bacterium cell replicates itself, the cell elongates with a strand of DNA at each end, and the cell splits in the middle into two identical daughter cells.
What is an autotrophic organism?
An organism that creates its own food.
What is a heterotrophic organism?
An organism which obtains its food from another source.
What are the types of autotrophic bacteria?
Photosynthetic and chemosynthetic.
What do photosynthetic bacteria do?
Make their own food using sunlight.
Eg: green sulphur bacteria.
What do chemosynthetic bacteria do?
Use energy from chemical reactions to generate food.
Eg: Nitrifying bacteria.
How do heterotrophic bacteria obtain food?
Secrete enzymes into their surroundings & absorb digested food.
What are the types of heterotrophic bacteria?
Saprophytic and parasitic.
What are saprophytic bacteria?
Organisms that take in their food from dead organic matter.
Known as decomposers, feed off decaying plants/animals. Eg: Bacteria of decay found in soil.
What are parasitic bacteria?
An organism that obtains its food from a live host & usually causes it harm.
What is mutation of bacteria?
The DNA loop in a bacterium cell changes slightly when replicating itself.
What is antibiotic resistance?
Mutated bacteria are no longer killed by an antibiotic and can reproduce quickly in an environment with no competition.
How does antibiotic resistance impact the use of antibiotics?
If bacteria change, antibiotics will no longer work, leading to bacteria dying and mutated bacteria multiplying due to lack of competition.
What are antibiotics?
Chemicals produced by microorganisms that stop the growth or kill other microorganisms without damaging human tissue.
What factors affect bacterial growth?
Temperature, oxygen concentration, pH, external solute concentration, pressure.
What is a limiting factor?
Something that slows down a process when it is in short supply.
What is the optimum temperature for most bacteria?
20-30 degrees, but some can tolerate higher temperatures.
What is the effect of low oxygen concentration on aerobic bacteria?
It will slow down bacterial growth.
What do anaerobic bacteria need to survive?
They do not need oxygen to survive.
Eg: Clostridium.
What are facultative anaerobes?
Bacteria that can respire with or without oxygen.
Eg: E. coli.
What are obligate anaerobes?
Bacteria that can only respire in the absence of oxygen.
Eg: Tetanus.
What is the optimum pH for most bacteria?
7-8, but there are exceptions.
What happens to bacteria in high external solute concentration?
They dehydrate and cannot reproduce.
How does high pressure affect bacterial growth?
It usually inhibits growth as bacterial cell walls are not strong enough.
What are the advantages of bacteria?
Used in industry, e.g., Lactobacillus in bioreactors for milk products, and genetically modified bacteria for drugs and vitamins.
What are the disadvantages of bacteria?
Can cause diseases (pathogenic bacteria) and lead to food decay.
What are pathogenic bacteria?
Bacteria which can cause harm to an organism.
What is asepsis?
The absence of all pathogens.
What is sterility?
The absence of all microorganisms.
What happens in the lag phase of the bacterial growth curve?
Bacteria adapt to their environment with little to no change in population.
What happens in the log phase of the bacterial growth curve?
Conditions are suitable for exponential growth, with the population doubling each generation.
What happens in the stationary phase of the bacterial growth curve?
No growth occurs; the rate of death equals the rate of birth.
What happens in the decline phase of the bacterial growth curve?
The bacteria population declines with a faster rate of death than birth.
What happens in the survival phase of the bacterial growth curve?
Some bacteria survive due to endospore formation despite competition.
What products can bacteria be used to make?
Cheese, amino acids, drugs & alcohol.
How can microorganisms be used?
As food themselves.
What do bacteria and fungi produce?
Edible forms of protein called ‘Single cell protein’.
What are the two ways bacteria can be used for processing?
Batch processing and continuous flow processing.
What is batch processing?
A fixed amount of sterile nutrient is added to a bioreactor at the start, and the bioreactor is emptied at the end of the production run.
What is an advantage of batch processing?
It is inexpensive.
What is continuous flow processing?
Nutrients are constantly fed into the bioreactor while the product is withdrawn constantly.
What is a disadvantage of continuous flow processing?
It is expensive and requires monitoring.
What is bioprocessing?
The use of enzyme-controlled reactions to produce a product.
What is a bioreactor?
A vessel in which bioprocessing takes place.
Why would antibiotic resistance arise in bacteria?
Overuse - people take too many antibiotics.
What part of the bacterium cell is responsible for antibiotic resistance?
Plasmid.
Is a bacteria cell motile and why?
Yes, as they have a flagellum.
What is a pathogen?
A disease-causing organism.
Name two beneficial bacteria.
Lactobacillus & Bifidobacteria.
Name two harmful bacteria.
E. coli & Salmonella.
What do the X and Y axes on a growth curve represent?
X = Time, Y = Number of microorganisms (population).
What is endospore formation?
When Bacteria can survive unfavourable conditions by producing endospores.
1.Chromosome replicates, new chromosome is surrounded by an endospore. The endospore has a tough wall which can withstand harsh conditions like high temps and chemicals etc.
2.Cell breaks down due to conditions and the endospore remains dormant until conditions change.
3.When conditions are favourable the endospore absorbs water and the wall breaks allowing the bacterium to replicate by binary fission again.
What are the benefits of symbiotic bacteria?
Production of vitamins.
