Exam 1 Lecture 1

Question 1

Robert Hooke

Answer 1

First to visualize “cells”

Question 2

Antonie van Leeuwenhoek

Answer 2

First to visualize microbes

Question 3

How far can we see with the unaided human eye?

Answer 3

40 micrometers (10^-6 m)

Question 4

Which tools can we use to best visualize microbes?

Answer 4

light microscope, electron microscope, x-ray crystallography

Question 5

Edward Jenner

Answer 5

reported cowpox vaccination against smallpox (one of the first successful vaccines)

Question 6

Florence Nightingale

Answer 6

discovers that hygiene is the best way to prevent infection/illness

Question 7

Louis Pasteur

Answer 7

pivotal in disproving spontaneous generation hypothesis, developed swan-necked flask experiment, shows microbes as causative agents of disease

Question 8

Koch

Answer 8

formed Koch’s postulates to show microbes as causative agents of disease

Question 9

Hans Christian Gram

Answer 9

developed gram stain, which is a key method to differentiate between gram-positive and gram-negative bacteria

Question 10

Paul Ehrlich

Answer 10

discovered arsphenamine aka 606 or salvarsan, the first effective treatment for syphilis

Question 11

Alexander Fleming

Answer 11

best known for discovering the world’s first broad antibiotic, penicillin

Question 12

Ernst Chain and Howard Florey

Answer 12

successfully purified and concentrated penicillin, also played a role in increasing the production of penicillin

Question 13

Gerhard Domagk

Answer 13

discovered sulfonamides as an effective treatment for bacterial infections

Question 14

Avery, MacLeod, McCarty

Answer 14

discovered that DNA is the substance that leads to bacterial transformation - this was proved by injecting purified DNA from Streptococcus into harmless bacteria of a mouse. the bacteria became virulent

Question 15

Watson, Crick, Rosalind Franklin

Answer 15

figured out the structure of DNA (helical)

Question 16

Sanger

Answer 16

discovered protein sequencing and DNA sequencing

Question 17

Rich Roberts

Answer 17

known for isolation of restriction enzymes, essential to cutting out specific regions of DNA

Question 18

Herb Boyer, Stanley Cohen

Answer 18

made significant contributions to recombinant DNA technology

Question 19

Kary Mullis

Answer 19

invented PCR, which is used to amplify a small sample of DNA

Question 20

Next Gen Sequencing

Answer 20

developed in the 2000s, allows for rapid and cheap DNA/RNA sequencing

Question 21

Cocci (coccus)

Answer 21

spherical

Question 22

Bacilli (bacillus)

Answer 22

rod-shaped

Question 23

Coccobacilli

Answer 23

intermediate between cocci and bacilli (short rods)

Question 24

Fusiform (gram-neg)

Answer 24

spindle-like shape

Question 25

Vibrio (gram-neg)

Answer 25

curved-rod shape

Question 26

Spirilla (gram-neg)

Answer 26

corkscrew (spiral) shape, rigid, flagella on outside of cells, most are NOT pathogenic

Question 27

Spirochetes (gram-neg)

Answer 27

corkscrew (spiral) shape, flexible, flagella is on the inside of cells in the periplasm, pathogenic (Lyme’s disease, syphilis)

Question 28

What are the multi-cellular arrangements bacteria can take on?

Answer 28

diplococci, chains, clusters, tetrad, biofilms

Question 29

What ribosomes do prokaryotes have?

Answer 29

70S

Question 30

What does the 70S ribosome consist of?

Answer 30

5S, 16S, 23S rRNA sequences (16S critical to identify start codon!)

also over 50 proteins

Question 31

Do prokaryotes contain sterols?

Answer 31

No - they contain hopanoids

Question 32

What is significant about Mycoplasma?

Answer 32

They do not have a cell wall! Therefore do not contain structures that are common for GP and GN bacteria (ex: do not contain PG). They do, however, contain cytoplasmic membrane

Question 33

Lipoteichoic acid

Answer 33

characteristic of Gram + bacteria, they are teichoic acids anchored to lipid membrane

Question 34

Do all bacteria have capsule/slime layer?

Answer 34

No, it depends on the species of bacteria specifically within GP and GN

Question 35

Do all bacteria have pili/flagella?

Answer 35

No, it depends on the species of bacteria specifically within GP and GN and if they have transformative/motility/adhesive properties

Question 36

O-specific side chains of LPS are found in…

Answer 36

LPS of Gram negative bacteria

Question 37

True or false: gram negative bacteria have outer membrane and inner membrane

Answer 37

True

Question 38

What does Lipid A do?

Answer 38

It is endotoxin, and when cell is lysed, endotoxin is released and can overstimulate the immune response

Question 39

What are functions of core polysaccharide of LPS?

Answer 39

• largely serve as disguise mechanisms to fool the immune system
• important for complement resistance

Question 40

Bacterial structures provide 4 main things:

Answer 40

1. staining differences
2. triggers innate response
3. triggers adaptive immune response
4. targets for small molecules that we can antibiotics or antimicrobials

Question 41

Framework for what is causing infection

Answer 41

Staining pattern, morphology, specimen site, patient history

Question 42

True or false: we can use DNA sequences to identify bacteria

Answer 42

True - we can use this information to diagnose, come up with a treatment plan, administer the appropriate antibiotic to interrupt infection

Question 43

How can we classify bacteria? (5 things)

Answer 43

1. Taxonomy
2. Phylogeny
3. Phenotype
4. Genotype
5. Microbiome

Question 44

Phenotype can tell us:

Answer 44

morphology, biochemical capabilities; fatty acid (membrane and by-products); mycolic acid analysis (found in the membrane of Mycobacteria)