Monera Flashcards
Are monera prokaryotic or eukaryotic?
Prokaryotic
How does monera reproduce?
Asexual - binary fission
Explain binary fission
When the bacterium cell gets to a certain size, the DNA strand replicates
2 identical strands
The cell grows and elongates and the cell splits = 2 similar sized cells
Are monera single celled or unicellular?
Single celled
What are the cell walls of monera made up of?
Sugars and protein
Nutrition of monera
Heterotrophic and autotrophic
[saprophytic, parasitic, chemosynthetic and photosynthetic]
How do endospores form?
The chromosome replicated and the new strand is enclosed by an endospore that was formed inside the parent plant
Parent cell breaks down and the endospore remains dormant
When conditions are suitable, endospore absorbs water and walls break down
What is sometimes present in a monera cell
Capsule
Mesosome
Plasmid
Flagellum
What is the function of mesosomes?
Respiration
What is the function of plasmid?
Contains genes responsible for bacterial resistance to antibiotics
What is the function of the cell wall?
Prevents swelling and bursting in solution less concentrated
What is the function of the flagellum?
Bacterial movement
What is a saprophytic bacteria?
Bacteria that feed on dead matter
What is parasitic bacteria?
It’s a bacteria that lives on a live host and causes harm
What are photosynthetic bacteria and give an example
Bacteria that use light to make food eg, purple sulfur
What are chemosynthetic bacteria and give an example?
Bacteria that use energy from chemical reactions to make food eg, nitrifying bacteria
What is an economic benefit of bacteria?
Lactobacillus
Genetically modified such as e.coli = make drugs and insulin
Economic disadvantage of bacteria?
Cause diseases eg, bacteria that cause cholera
Food decay - lactobacillus turns milk sour
What are the three types of bacteria and give examples?
Round - coccus - pneumonia and sore throat
Rod - bacillus - TB and Tetanus
Spiral - spirillum - syphilis and cholera
How do bacteria evolve resistant to new antibiotics?
Short life cycle + fast rate of reproduction
Potential abuse of antibiotics
Overuse
Failure to complete treatment allow bacteria to survive and grow
What is batch culture?
Fixed amount of sterile nutrient is added to micro organisms in bio reactor
Micro organisms go through lag, log, stationary phases
Nutrients are used up and the product is formed
Product is made at log or stationary stage and stopped before decline stage
What is continuous flow?
Nutrients added continuously [at all times] and at the same time the culture medium [with micro organisms] are withdrawn continuously. Maintained at log phase and the product formed all ten time for a long period of time
What is the difference between asepsis and sterility?
Asepsis - free of pathogens
Sterility - free of micro-organisms
What is the optimum temp and ph for bacteria?
Temperature - 20-30 degrees
Ph - most neutral ph
What are aerobic bacteria and give an example
Require oxygen for respiration eg, streptococcus
What are anaerobic bacteria and give an example
Doesn’t require oxygen to respire
Clostridium
What are facultative bacteria and give an example
Can respire with or without bacteria eg, e.coli
What are obligate anaerobes and give an example
Can only respire in absence of oxygen eg, clostridium tetani [causes tetanus]
What are antibiotics?
Chemicals produced by micro-organisms that stop the growth of, or kill other micro organisms without damaging human tissue
What is the lag phase?
Bacteria are adapting to new environment, little if any increase
What is the log phase?
Bacteria have adapted and are reproducing at their maximum rate
What is the stationary phase?
No increase in bacterial numbers, lack of food, lack of space
Death rate = birth rate
What is the decline phase?
Bacteria numbers fall when the death rate is greater than rate of reproduction
Give one way in which bacteria cope with unfavourable conditions
Forcing endospores
Distinguish between batch processing and continuous flow in food processing. Refer to stages in answer
Batch - fixed amount of nutrients added at beginning, all stages occur
Continuous flow - nutrients are constantly added to bioreactor, Log stage is maintained
Give an example of a harmful member of the monera
Bacterium of disease - streptococcus pyogenes
Under what circumstances does a bacterial cell form an endospore?
Harsh conditions
Name two types of heterotrophic nutrition used by bacteria?
Parasitic
Saprophytic
Describe how oxygen demand changes as the number of bacteria in the water changes and give a reason
No.of bacteria inc and oxygen demand inc
No.of bacteria dec and oxygen demand dec
More bacteria require more o2
Diagram of growth curve of bacteria!!
Know how to draw
What are the purpose of antibiotics
Treat infections
Explain what is meant by antibiotic resistance and explain how it may develop
Bacteria fungi are not killed and become immune to antibiotics
Develops - misuse of antibiotics
Other than being prokaryotic, state two ways in which a typical bacterial cell differs from a typical human cell
Cell wall, plasmid
Role of parasites in the overal scheme of nature
Natural selection
