WEEK 2 (part II): BACTERIAL GROWTH, NUTRITION, METABOLISM, AND GENETICS

Question 1

energy source: light
carbon source: CO2

Answer 1

Photoautotroph

Question 2

energy source: light
carbon source: organic compounds

Answer 2

Photoheterotroph

Question 3

energy source: chemical
carbon source: CO2

Answer 3

Chemoautotroph

Question 4

energy source: chemical
carbon source: organic compounds

Answer 4

Chemoheterotroph

Question 5

Psychrophiles/Cryophiles

Answer 5

0°C to 20 °C

Question 6

Mesophiles

Answer 6

20°C to 45 °C

Question 7

Thermophiles

Answer 7

50°C to 60 °C

Question 8

Requires oxygen for growth

Answer 8

Obligate aerobes

Question 9

Can grow either with or without oxygen

Answer 9

Facultative anaerobes

Question 10

Cannot grow in the presence of oxygen

Answer 10

Obligate anaerobes

Question 11

Can survive in the presence of oxygen but
do not use oxygen for metabolism

Answer 11

Aerotolerant anaerobes

Question 12

Requires a reduced level of oxygen for growth

Answer 12

Microaerophiles

Question 13

do not require high salt concentration but
grows in 2% to 15% salt concentration.

Answer 13

Facultative halophiles

Question 13

Requires extra carbon dioxide (5% to 10%)

Answer 13

Capnophiles

Question 14

requires high salt concentrations or hypertonic environments (30% salt).

Answer 14

Obligate halophiles

Question 15

little or no cell division; intense metabolic
activity

Answer 15

Lag Phase

Question 15

AKA “Exponential growth phase”; cell
begins to divide; active cellular
reproduction with constant minimum
generation time; cells are at their most
active state

Answer 15

Log (Logarithmic) Phase

Question 16

Time required for one cell to divide into two
cells

Answer 16

Generation Time (Doubling time)

Question 16

the density (cloudiness or turbidity) of
bacterial culture in log phase can be
correlated to CFU/ml of the culture.
Method used in AST.

Answer 16

Density measurement

Question 17

used to estimate the number of bacteria.

Answer 17

Direct counting under the microscope

Question 17

growth rate slows down (# of new cells = #
of microbial deaths = population stabilizes)
period of equilibrium

Answer 17

Stationary Phase

Question 18

growing dilution of colony-forming units per
milliliter(CFU/ml)

Answer 18

Direct plate count

Question 18

logarithmic decline; number of deaths
exceeds the number of new cells formed

Answer 18

Death Phase

Question 19

used the phenotypic markers for the identification of bacteria

Answer 19

Metabolic differences

Question 19

Two mechanisms of Carbohydrate utilization

Answer 19

Fermentation and Respiration

Question 20

obligate aerobes and facultative anaerobes ➢ Aerobic process of energy production ➢ ATP-generating process; glucose is completely broken down

Answer 20

Respiration (oxidation)

Question 21

➢ Anaerobic process of energy generation ➢ The end products are mixtures of lactate, butyrate, ethanol, and acetoin

Answer 21

Fermentation

Question 22

➢ Major pathway in conversion of glucose to pyruvate ➢ Anaerobic; does not require oxygen ➢ Used by many bacteria, including members of Enterobacteriaceae ➢ End-product: 2 molecules of pyruvic acid

Answer 22

Embden-Meyerhof-Parnas (EMP Glycolytic Pathway)

Question 22

➢ Used by heterolactic fermenting bacteria like Lactobacilli and Brucella abortus, which lacks some of the enzymes required in EMP pathway. ➢ Provides pentoses for nucleotide synthesis ➢ While it does involve oxidation of glucose, its primary role is anabolic rather than catabolic.

Answer 22

Pentose Phosphate pathway

Question 23

➢ Converts glucose-6-phosphate (rather than glucose) to pyruvate and glyceraldehyde phosphate ➢ Aerobic process used by Pseudomonas, Alcaligenes, Enterococcus faecalis, and other bacteria lacking certain glycolytic enzyme ➢ End-product: glyceraldhyde-3-phosphate and pyruvic acid

Answer 23

Entner-Doudoroff pathway

Question 24

Aerobic Pathways

Answer 24

Aerobic Utilization of Pyruvate (oxidation)

Question 24

allowing complete oxidation of pyruvate

Answer 24

Krebs Cycle (TCA Cycle)

Question 25

generate energy in the form of ATP *This cycle results in the production of acid and the evolution of carbon dioxide.

Answer 25

Electron Transport Chain

Question 25

eukaryote: cytoplasm prokaryote: cytoplasm

Answer 25

Glycolysis

Question 26

eukaryote: mitochondrial matrix prokaryote: cytoplasm

Answer 26

Krebs Cycle

Question 27

eukaryote: mitochondrial inner membrane prokaryote: plasma membrane

Answer 27

ETC

Question 28

This results to results to acid production resulting to color change

Answer 28

Sugar Fermentation

Question 28

➢ Determine the ability of an organism to use sodium citrate, malonate or acetate as the sole source of carbon ➢ Indicator: Bromthymol blue

Answer 28

Citrate, Malonate, or Acetate Utilization

Question 29

➢ Determines the end products of glucose fermentation ➢ First pathway produces mixed acid (MR becomes red) ➢ Second pathway produces acetoin (VP becomes pink-red)

Answer 29

MR-VP (Clark and Lubs medium)

Question 29

Yeasts → ethanol

Answer 29

Alcohol fermentation

Question 30

Streptococcus and Lactobacillus → lactic acid

Answer 30

Homolactic fermentation

Question 31

Lactobacillus → mixed acids (lactic, formic and acetic acid; alcohols)

Answer 31

Heterolactic fermentation

Question 31

Propionibacterium acnes → propionic acid

Answer 31

Propionic acid fermentation

Question 32

Escherichia, Salmonella, and Shigella → mixed acids (lactic, acetic, succinic and formic acids)

Answer 32

Mixed acid fermentation

Question 32

Klebsiella, Enterobacter, and Serratia → acetoin and 2,3-butanediol

Answer 32

Butanediol fermentation

Question 33

Clostridium spp., Fusobacterium, and Eubacterium → butyric acid, acetic acid, etc.

Answer 33

Butyric acid fermentation

Question 33

A pairs with?

Answer 33

T

Question 34

___ pairs with C

Answer 34

G

Question 34

A DNA sequence that carry hereditary information that encodes for a specific product (peptide/ RNA)

Answer 34

Gene

Question 35

Duplication of chromosomal DNA for insertion into a daughter cell

Answer 35

Replication

Question 35

all genes taken together within an organism. (e.g. 103 – 106 ) ➢ i. Chromosome ➢ ii. Extrachromosomal elements

Answer 35

Genome

Question 36

Contains all genes essential for growth and replication

Answer 36

Chromosome

Question 36

encodes products that are determinants of antimicrobial resistance

Answer 36

Plasmids

Question 37

simplest mobile piece of DNA

Answer 37

IS (insertion sequence)

Question 37

mobile elements that contain additional genes

Answer 37

Transposons

Question 38

is the synthesis of single stranded RNA (w/ the aid of the enzyme RNA polymerase) using one strand of the DNA as the template

Answer 38

Transcription

Question 39

code consists of triplets of nucleotide bases.

Answer 39

Codons

Question 39

triplet of bases on the tRNA that bind the triplet of bases on the mRNA. It identifies w/c amino acid will be in a specific location in the protein

Answer 39

Anticodon

Question 40

➢ synthesis of specific protein ➢ conversion of mRNA sequence into amino acids ➢ the number and sequence of amino acids in a polypeptide & thus the character of particular protein are determined by sequence of codons in the mRNA molecule.

Answer 40

Translation

Question 40

Method by which genes are transferred or exchanged between homologous regions on 2 DNA molecules

Answer 40

Genetic Recombination

Question 40

Insertion or deletion of one or more nucleotide pairs.

Answer 40

Frameshift mutation

Question 41

Change in the original nucleotide sequence of a gene or genes.

Answer 41

Mutations

Question 41

Change in one base

Answer 41

Base Substitution (Point mutation)

Question 42

Two courses of Transduction

Answer 42

Lytic Cycle and Lysogenic Cycle

Question 43

Uptake and incorporation of naked DNA into a bacterial cell

Answer 43

Transformation

Question 43

able to take up free DNA. ➢ H. influenzae ➢ S. pneumoniae ➢ N. gonorrhoeae

Answer 43

Competent

Question 43

phage DNA incorp. to bact. genes; phage DNA expressed in site; lysis ensues at later time

Answer 43

Lysogenic Cycle

Question 43

Transfer of bacterial genes by a bacteriophage

Answer 43

Transduction

Question 43

replication of bact. chrom. disrupted; phage particles formed; cell lysed and phage released

Answer 43

Lytic Cycle

Question 43

➢ Mobilization of donor bacterium’s Plasmid ➢ Plasmid is replicated

Answer 43

Plasmid Transfer

Question 43

➢ Due to cell-to-cell contact- sex pilus ➢ Mobilization of donor bacterium’s chromosome ➢ Both plasmids and chromosomal genes can be transferred by this method

Answer 43

Conjugation: Donor to recipient strain

Question 43

produced by bacteria to cut incoming foreign DNA to prevent incorporation into their genome

Answer 43

Restriction Enzymes

Question 43

be incorporated into chromosome of plasmids. “Jumping genes”

Answer 43

Transposon Transfer