Intro to infection Flashcards
What are the 4 major groups of human pathogens?
Protozoa
Fungi
Bacteria
Viruses
Which 2 groups of human pathogens are eukaryotes
protozoa
fungi
what type of cell is bacteria
prokaryote
What are viruses
non-living/obligate parasites
How is DNA stored in prokaryotes
single circular chromosome
How are proteins coded for in prokaryotes
using a gene structure rather than introns/exons
How do bacteria maintain their shape
rigid cell wall
which structures are usually present in a prokaryotic cell
cell envelope
cytoplasmic membrane
DNA (single chromosome)
ribosomes
What structures are sometime found in a prokaryotic cell
Flagellum
fimbriae
capsule
What is a nucleoid in a prokaryote
contains dna and associated proteins (not histomes)
no membrane
no defined location
What is the cytoplasmic membrane made up of
lipid bilayer
What are the main functions of the cytoplasmic membrane
retain cytoplasm
selective barrier
transport
reaction surface
What drives the ATP synthase for energy across the plasma membrane of the prokaryote
electrons passed through electron acceptors
This leads to protons being passed outside the membrane forming a gradient
What is the central dogma for prokaryotes
gene
mRNA
ribosome
protein
2nd structure etc
export/assembly
What is the cell wall made up of
peptidoglycan
what does the cell wall contain
repeated sugar chains
peptide side bridges
What makes a cell wall gram positive
multi-layer and often a secondary polymer
what makes a cell wall gram negative
outer membrane
often contains LPS
contains periplasmic space
What is Lipopolysaccharide (LPS)
Takes up most of the outer surface of gram negative bacteria
Antigen
What is the function of Flagella and Fimbriae in both gram positive and negative bacteria
sex
motility
What do prokaryotes need for growth
food source
oxygen and hydrogen
nitrogen source - salts
What prokaryotes need body temperature for growth
mesophiles
What is bacterial survival dependant on
pH of environment
When is bacterial growth in a stationary phase
when there is a limiting factor, leads to a gradual decline
how are bacteria cooperative
can form communities from colony development and differentiation - i.e. biofilms
