Microbiology 1 Flashcards
Define microbiology?
- The study of microorganisms
- Micro = small
- Biology = the study of living things
What is microbiology important for?
- Medicine
- Environmental science
- Food and drink production
- Fundamental research
- Agriculture
- Pharmaceutical industry
- Genetic engineering
Describe the process of producing antibiotics.
- Produced from microorganisms
- Antibiotics are isolated from natural microorganisms by the process of fermentation
- Many microbial cells convert raw materials or substrate into valuable organic compounds
- microbial cells produce intracellular and extracellular enzymes important for the success of pharmaceutical fermentation process
Define eukaryotic cells.
Any cell that contains a clearly defined nucleus and membrane bound organelles
Define prokaryotic cells.
Any unicellular organism that does not contain a membrane bound nucleus or organelles
Describe DNA replication of eukaryotic cells.
Highly regulated with selective origins and sequences
Describe DNA replication of prokaryotic cells.
Replicates entire genome at once
Describe how antibiotic resistance spreads. (from animals)
Animals get antibiotics and develop resistance in their guts
- Drug-resistant b bacteria can remain on meat from animals - when not handled or cooked properly, the bacteria can spread to humans
- Fertiliser or water containing animal faces and drug-resistant bacteria is used on food crops
- Drug-resistant bacteria in the animal faces can remain on crops and be eaten - these bacteria can remain in the human gut
- Resistant bacteria spreads further in the community
Describe how antibiotic resistance spreads (starting from humans).
- Person gets antibiotics and develops resistant bacteria in his gut
- Person stays home and in th general community and spreads resistant bacteria
- Person gets care at a hospital, nursing home or other inpatient care facility
- Resistant germs and bacteria spread to other patients and healthcare providers within the healthcare facility
- Resistant bacteria spreads further in the community
Describe the bacterial cell wall.
Thick and rigid due to peptidoglycan (murrain)
What are the two distinct structural types for bacterial cells?
Gram negative - does not retain dye methyl violet
Gram positive - retain the stain
State the two major roles of the bacterial cell wall.
a) to protect the cell against osmotic rupture particularly in dilated media and also against certain possible mechanical damage
b) To assign bacterial shapes, their subsequent major division into Gram positive and gram negative microorganisms and their antigenic attributes
Describe the structure of gram-negative cells.
- Have much thinner layer of peptidoglycan, making the wall less sturdy
- The structure is made more complex by the presence of a layer of lipoprotein, polysaccharide and phospholipid known as the outer membrane
Describe the structure of gram-positive cells.
- Relatively simple in structure
- Comprising several layers of peptidoglycan connected to each other by cross-linkages to form a strong, rigid scaffolding
- Contain acidic polysaccharides called teichoic acids
- Phosphate groups impart on overall negative charge to the cell surface
How do most bacteria grow?
Binary fission - one cell undergoes division to give rise to the formation of two cells
