Microbes

Question 1

4 types of micro organisms

Answer 1

Viruses
Bacteria
Fungi
Parasites

Question 2

Size order of microorganisms (small to big)

Answer 2

Prions, proteins, virus, mycoplasma/chlamydiae/rickettsiae, mitochondria, bacteria, eukaryotic cells, worms

Question 3

Virus structure (inside to out)

Answer 3

DNA/RNA (single/double strand, -ve/+ve)
Protein coat
Envelope
Spikes (act as receptors to attach to host cells)

Question 4

How can viruses be treated

Answer 4

By interfering with spike proteins and the way they interact with host cells to prevent attachment

Question 5

How are viruses classified

Answer 5

Baltimore classification (7 classes)
Based on what nucleic acid they contain

Question 6

What are bacteriophages

Answer 6

Infect bacteria by feeding on them
Can code for virulence factors
Don’t infect humans directly

Question 7

Bacteria structure (inside out)

Answer 7

Chromosomal DNA (double strand, wrapped into a tight ball)
Plasmids (mobile DNA loops, can transfer to other bacteria and carry resistance genes)
Ribosomes
Plasma membrane
Cell wall
Capsule (polysaccharide)

Question 8

Bacterial shapes

Answer 8

Coccus (circular and round plural = cocci)
Spirillus (spiral)
Bacillus (rods)

Question 9

Arrangement of cocci

Answer 9

Cluster (staph)

Chain (strep)

Question 10

Gram positive

Answer 10

Peptidoglycan holds stain = positive
No outer lipopolysaccharide protein membrane

(Still has plasma membrane, periplasmic space)

Question 11

Gram negative

Answer 11

Has lipopolysaccharide and protein outer membrane

Still has plasma membrane, peptidoglycan BUT THINNER and periplasmic space between layers

Question 12

Aerobes

Answer 12

Can survive in presence of oxygen

Question 13

Obligate aerobes

Answer 13

Require oxygen to survive

Question 14

Anaerobes

Answer 14

Can survive without oxygen

Question 15

Obligate anaerobes

Answer 15

Need an oxygen free environment to survive (unless spores)

Question 16

How do spores work?

Answer 16

Dormant form

Thick coating which protects it from oxygen, temp, chemicals, dehydration

Question 17

How are bacteria and fungi named

Answer 17

Linnaean taxonomy (genus then specie)
Surname then first name 
Names can change and can contain info about growth, typing or anti microbial susceptibility

Question 18

Mechanisms of bacterial pathogenesis

Answer 18

Virulence factors and toxins

Question 19

Virulence factors

Answer 19

Host entry (polysaccharide capsule)
Adherence (pilli)
Invasiveness (collagenase allows to easily move through matrix)
Iron sequestration (siderophores and co factor for many enzymes)

Question 20

Toxins

Answer 20

Exotoxins - made inside cell and released to outside

Endotoxins - lipopolysaccharide bacteria wall breaks and is released when cell is broken down

Question 21

Prokaryotes vs eukaryotes

Answer 21

Prokaryotes
Chromosomes are circular and usually single
No nuclear envelope or nucleoli
No membrane bound organelles
Cell wall present (peptidoglycan)
Plasma membrane has no carbohydrate/sterols
Ribosome 70s

Eukaryotes
Multiple chromosomes
Membrane bound nucleus and nucleoli
Membrane bound organelles
Cell wall present in plant cells (no peptidoglycan)
Plasma membrane has carbohydrate and sterols
80s Ribosome

Question 22

Two types of fungi

Answer 22

Yeast (single celled) - Candida albicans (thrush)

Moulds (multicells) - dermatophytes (athletes foot)

Question 23

Parasites two types

Answer 23

Protozoa (single celled) - plasmodium falciparum (malaria)

Helminths (worms, multicellular) - tapeworm, ringworm, roundworms

Question 24

Bacteria present on skin (gram positive)

Answer 24

Staphylococcus aureus
Staphylococcus epidermidis
Streptococcus (group A)

Corynebacterium species
Proprionibacterium acnes

Question 25

Examining bacteria

Answer 25

MCS
Microscopy, culture, sensitivity
Full blood count
Culture bacteria

Question 26

Shapes of fungi

Answer 26

Hyphae and form thread like filaments

Question 27

Gram stain test

Answer 27

Crystal violet and iodine then stripped with alcohol