Microbiology Flashcards
What are viruses and how do they replicate?
Small infectious agents
Can only replicate inside other living cells
What are prions and how are they replicated?
Infectious abnormally folded protein
Replicated by inducing normal proteins to form an amyloid plaque
Replicates itself without the need for genetic information
Describe protozoas
Single-celled
Heterotrophic
Eukaryotic
Describe helminths and how are they separated?
Multicellular
Worm like parasites
Separated into shapes:
Flukes
Tapeworms
Roundworms
Describe bacteria
Microscopic
Single-celled
Prokaryotic
Describe the cell walls and colour of gram positive and gram negative
Gram positive has thick cell wall and becomes dark purple
Gram negative has inner and outer membrane and becomes light pink
Describe endotoxins
Lipopolysaccharide complex associated with the outer membrane of gram -ve
Describe exotoxins
Usually secreted by bacteria and act at a site removed from bacterial growth
What are the 5 shapes of bacteria?
Cocci = round
Coccobacilli = oval thing
Bacillus = rod
Vibrio = sausage shape
Spirochete = spirally thing
Cytosol
Contents of cell within plasma membrane excluding nucleus and organelles
Nucleus
Contains DNA, site of transcription
Cytoplasm
Contents of cell within plasma membrane excluding nucleus
RER
Has ribosomes bound to cytosolic surface, involved in protein synthesis
SER
No ribosomes bound, involved in lipid synthesis
Golgi Apparatus
Sorting and modification of proteins
Mitochondria
Site of ATP production
Peroxisome
Oxidation of organic molecules resulting in their breakdown
What is the role of endosome?
Processes and sorts molecules that have been internalised into the cell
What do lysosomes contain and what is their role?
Contains digestive enzymes that break down macromolecules
Plasma Membrane
Selectively permeable layer that surrounds the cell
Phospholipid and protein
Chemical messengers interacting with receptors
Anchors cells to the extracellular matrix
What can normal bacterial flora do and what can it be disrupted by?
Protection against pathogenic bacteria
Aiding digestion
Vitamin production
Stimulation of immune response
Can be disrupted by:
Compromised immune system
Ageing
Antibiotic treatment
Prolonged hospitalisation
Pathogenic and non-pathogenic bacteria
Pathogenic bacteria can cause or has the potential to cause disease or infection
Non-pathogenic bacteria do not cause disease
Name 5 virulence factors
Factors that make bacteria pathogenic:
Entry into host
Antibiotic resistance
Toxin production
Immune evasion
Invasiveness
How are viruses classified?
Viruses can’t be classified by disease so are classified by their nucleic acid
Viral Replication and Protein Synthesis
Nucleic acid is copied and viral proteins are produced
