Bacteria and fungi

Question 1

What bacteria causes tuberculosis

Answer 1

Myobacterium tuberculosis

Question 2

What is a microorganism

Answer 2

an organism that we can only see through a microscope
bacteria, algae, fungi and protozoa are all microorganisms

Question 3

What bacteria causes diphtheria

Answer 3

Corynebacterium diphtheriae

Question 4

What bacteria causes cholera

Answer 4

Vibrio cholera

Question 5

What bacteria causes whooping cough

Answer 5

Bordetella pertussis

Question 6

What bacteria causes plague

Answer 6

Yertinia pestis

Question 7

What bacteria causes gonorrhoea

Answer 7

Neiserria gonorrhoea

Question 8

What bacteria causes salmonella

Answer 8

Salmonella enterditis

Question 9

Name the 3 good bacteria and the key words

Answer 9

Key words microbiome, probiotic, microbiota, gut bacteria

Lactobacillus
Streptococcus
Bifdobacterium

Question 10

What did robert Koch do

Answer 10

Father of microbiology
He found the causative agents of 3 diseases:

Anthrax, Tubercolosis and cholera

Question 11

Kochs postulates - what are they

Answer 11

WHITEBOARD!!! YOU KNOW THIS

Question 12

What is an asymptomatic carrier

Answer 12

They carry the disease but they don’t have the active form (but they can still pass it onto others)

Question 13

What is the tree of life, which ones are eukaryotes and which ones are prokaryotes

Answer 13

Bacteria , archaea , fungi

Bacteria and archaea are PROKARYOTES
fungi, protozoa and algae and EUKARYOTES

Question 14

CELL WALLS OF BACTERIA, FUNGI, VIRUS AND PROTIST

Answer 14

bacteria = peptidoglycan
fungi = chitin
virus = capsid instead (NO CELL WALL)
protist = NO CELL WALL

Question 15

explain the structure of peptidoglycan in bacteria cell wall

Answer 15

we have NAG and NAM (repeating units of sugar type molecules)

the sheets of NAG and NAM are linked by peptide bridges which hold the sheets together on a horizontal plate

then these sheets build up in layers by amino acids joining them into those layers

Question 16

Gram positive colour

Answer 16

Purple / blue

Question 17

Gram negative colour

Answer 17

Pink/red

Question 18

describe gram negative peptidoglycan components

Answer 18

thin peptidoglycan
no teichoic acids
also has outer membrane

Question 19

Outer membrane in gram negative contains

Answer 19

Lipopolysaccharide
Lipoproteins
Phospholipid
Porin protein

Question 20

Gram negative - what is lipopolysaccharide composed of

Answer 20

Lipid A (endotoxin)
core polysaccharide
O - specific polysaccharide

Question 21

Gram positive structure

Answer 21

Thick peptidoglycan
Teichoic acids
In acid-fast cells, contains mycolic acid
NO OUTER MEMBRANE

Question 22

Gram positive cell walls

Answer 22

Teichoic acids
Lipoteichoic acid links to plasma membrane
Wall teichoic acid links to peptidoglycan

May regulate movement of cations

Polysaccharides provide antigenic variation
May change immune responses of indivuals

Question 23

gram staining method - explain each step

Answer 23

1) crystal violet - primary stain that is added
Gram positive goes purple
Gram negative goes blue

2) iodine - mordant makes dye less soluble so it adheres to the cell wall

3) alcohol - decolourizer washes away the stain of gram negative cells
cell effect = gram negative goes colourless

4) safranin - counter stain which allows dye adherence of gram negative cell walls
cell effect = gram negative goes pink
gram positive goes purple

Question 24

Describe the structure and purpose of a capsule

Answer 24

This is the further outler layer
It is made up of a polysaccharide

its function is to protect against phagocytes (primary response) and protect against antimicrobial agents (secondary function)

Question 25

Capsules are most common in gram negative bacteria which are these

Answer 25

Escherichia coli, Klebsiella pneumoniae, Haemophilus influenzae

Question 26

Capsules are also present in gram positive cells which are

Answer 26

Streptococcus pyogenes possess a hyaluronic acid capsule Considered a virulence factor for Streptococcus sp

Question 27

Plasma Membrane in bacterial cell

Answer 27

Has a phospholipid bilayer Peripheral proteins Integral proteins (within bilayer) Transmembrane proteins

Question 28

Prokaryotic Ribosomes

Answer 28

Assemble proteins from amino acids based on mRNA have 70 s 16 s RNA

Question 29

Plasmids = in prokaryotes

Answer 29

Small circular or linear DNA molecules Carry unessential genes (doesn’t mean its unimportant) Can confer pathogenic and therapeutic properties Transferable between bacteria

Question 30

some bacteria can make endospores - which ones are these

Answer 30

Highly resistant survival structures produced by some Gram +ve Bacteria: Bacillus, Clostridium Highly dehydrated Contains essential macromolecules Calcium dipicolinate and small acid-soluble proteins absent from vegetative cells, help as receptors

Question 31

Flagella - the different types

Answer 31

a) monotrichous b) amphtrichous c) lophotricous d) petritrichous

Question 32

Flagella - structure

Answer 32

Outside cell wall Made of chains of flagellin Attached to a protein hook Anchored to the wall and membrane by the basal body

Question 33

3 different structure of fungi

Answer 33

1) unicellular 2) filamentous 3) dimorphic

Question 34

what are yeasts

Answer 34

they are unicellular fungi candida species is more common Thrush Candida auris Emerging pathogen Superbug

Question 35

Moulds

Answer 35

The fungal biomass consists of hyphae Generate spores

Question 36

Dimorphism

Answer 36

Pathogenic dimorphic fungi are yeast at 37°C, and mold like at 25°C

Question 37

Spores

Answer 37

Many fungi (possibly all) produce spores Very small and easily dispersed Many wind dispersed Exposed to spore all the time Immune status that determines infection Environmental factors Temperature Humidity

Question 38

Fungal Infections(Mycoses)

Answer 38

Cutaneous mycoses (Tinea ...) subcutaneous mycoses = Deeper tissue infection AND Puncture wounds

Question 39

Systemic Mycoses, true and opportunist pathogens (fungal infections deep in the body)

Answer 39

true pathogens = start in the lungs and spread to the body Opportunist pathogens = accosiated with immune response (candida sp, aspergilus ap and cryptococcus)

Question 40

good and bad fungi

Answer 40

Penicillium spp.—antibiotic production Penicillium roqueforti—blue cheese Penicillium spp.—blue and green molds on bread, cheese, fruits, vegetables Aspergillus flavus—aflatoxins (moldy peanuts) A. flavus/A. niger--aspergillosis

Question 41

Candida Infections

Answer 41

Commonest fungal infection May be superficial or systemic Associated with body flora disruption and immune issues

Question 42

Penicillium chrysogenum

Answer 42

Penicillin prevents cross-linking of small peptide chains in peptidoglycan, the main wall polymer in bacteria. Newly formed cells are abnormal in shape and susceptible to osmotic lysis.