Lectures 1-3

Question 1

Anton van Leeuwenhoek (1632-1723)

Answer 1

first simple microscope (200x)

Question 2

Aristotle

Answer 2

spontaneous generation
abiogenesis

challenged by Redi in 1600s and conclusively disproved by Pasteur 1800s

Question 3

Robert Koch

Answer 3

discovered mycobacterium tuberculosis

had 4 postulates:
1.

Question 4

Alexander Fleming

Answer 4

discovery of antibiotics
syphillus
Penicillin notam

Question 5

Edward Jenner

Answer 5

smallpox

Question 6

how have causes of death changed over the years

Answer 6

way fewer deaths from infectious diseases

highest killers changed from flu/pneumonia/TB to heart disease/cancer/stroke

Question 7

how is the ‘tree of life’ generated

Answer 7

comparison of nucleic acid sequences

Question 8

Woese

Answer 8

defined/named the group - Archea - using phylogenetic taxonomy

Question 9

3 domains of life

Answer 9

bacteria
eukaryota
archaea

Question 10

which organelles contain their own DNA

Answer 10

mitochondria and plastids

Question 11

where do mitochondrial proteins cluster on the bacterial tree

Answer 11

near the alpha-proteobacteria

Question 12

where do chloroplast proteins cluster on the bacterial tree

Answer 12

near the origin cyanobacteria

Question 13

what does serial endosymbiosis require

Answer 13

a gradual change from prokaryote to eukaryote

Question 14

archezoa

Answer 14

protozoa that primitively lacks mitochondria

Question 15

microsporidia

Answer 15

spore-forming fungus that contain mitochondrion

Question 16

hydrogen hypothesis

Answer 16

a way in which the mitochondrion arose as an endosymbiont within a prokaryote (an archaeon), giving rise to a symbiotic association of two cells from which the first eukaryotic cell could have arisen.

Question 17

interspecies hydrogen transfer

Answer 17

syntrophic process

Question 18

endosymbiosis

Answer 18

one bacterium engulfs the other
both bacteria benefit from arrangement
internal bacteria is passed on down generations

evidence shown through DNA and ribosomes in cyanobacteria

Question 19

endosymbiotic gene transfer

Answer 19

inevitable

genome decreased in size

Question 20

reclimona americana mitochondrial genome

Answer 20

most gene rich mitochondrial genome

more genes than human genome

Question 21

cytoplasmic membrane

Answer 21

phospolipid bilayer
strengthened by hopanoids
essential for mycoplasmas

class of phospholipids =phosphatidylethanolamine

Question 22

what is different about archaea cytoplasmic membrane

Answer 22

ether group not ester on the phospholipid

Question 23

cell wall

Answer 23

peptidoglycan - murein

can be 90% gram +ve and 10% gram -ve

Question 24

outer membrane

Answer 24

different from cytoplasmic membrane
not just phospholipids

second lipid bilayer - gram -ve
large polysaccharide component

Question 25

3 lens types on light microscope

Answer 25

ocular - eyepiece
objective
condenser

Question 26

numerical aperture

Answer 26

light gathering ability

Question 27

calculation for diameter of smallest resolvable object

Answer 27

0.5lamda/numerical aperture

Question 28

3 components of cell wall

Answer 28

periplasm
peptidoglycan
outer membrane (contains lipopolysaccharides)

Question 29

where can biofilms form

Answer 29

1. solid substances in contact with moisture
2. soft tissue surfaces in living organisms
3. liquid air interfaces

biofilms often called slime

Question 30

capsules

Answer 30

polysaccharide or protein or both

surround bacteria outside outer membrane

play a role in pathogenesis and biofilm formation

tightly packed - most stains cannot adhere to capsule

enhances ability of bacteria to cause disease

Question 31

what initiates the formation of a biofilm

Answer 31

attachment of free-floating micro-organisms to a surface
- attach via weak, reversible van der waals

anchor permanently using pili if not immediately separated

Question 32

5 stages of biofilm development

Answer 32

1. Initial attachment - free-floating bacteria attach - adhesion - (weak, reversible Van der Waals)
2. Irreversible attachment - bacterial cells aggregate and attach - formation of monolayer
3. Maturation I - growth and division of bacteria
4. Maturation II - mature biofilm formation
5. Dispersion - part of biofilm disperses to provide free-floating bacteria for further colonisation

Question 33

cell surface structures

Answer 33

fimbriae and pili
biofilm
capsule
flagella

Question 34

fimbriae and pili

properties and function

Answer 34

proteinaceous but can be glycosylated
roles in pathogenesis, biofilm formation and conjugation
involved in twitching motility

Question 35

what is a fimbriae

Answer 35

short pilus
found in gram -ve bacteria
some contain lectin to target specific cells
used to attach the bacteria to a surface

Question 36

what are pili

Answer 36

hair-like appendages found on the surface of many bacteria

Question 37

flagella

Answer 37

Multimeric protein complex traversing both inner and outer membranes

helical in shape (central rod surrounded by rings)

involved in locomotion

Question 38

4 types of flagellar distribution on bacteria

Answer 38

1. peritrichous - many flagella all over
2. polar/monotrichous - single flagellum at one end
3. lophotrichous - tufts of flagella
4. amphitrichous - single flagella at either end

Question 39

endospore

Answer 39

a dormant, tough, non-reproductive structure produced by a small number of bacteria from the Firmicute family

function of most endospores is to ensure the survival of a bacterium through periods of environmental stress.