2.1 Bacterial properties

Question 1

Bacterial nomenclature

Answer 1

Genus species – all italicized or underlined if cannot italicize.

Question 2

two examples of bacteria given nomenclature

Answer 2

Bacillus anthracis – causitive agent of anthrax
Escherichia coli (E. coli)

Question 3

common bacterial shapes

Answer 3

coccus, bacillus, vibrio, coccobacillus, spirillum, spirochete

Question 4

coccus

Answer 4

round, sphere-like

Question 5

baccilus

Answer 5

rod-like

Question 6

vibrio

Answer 6

comma shaped

Question 7

coccobaccilus

Answer 7

either short rods or elongated coccus – whichever way you want to think about it

Question 8

spirillum

Answer 8

sprial, rigid.

Question 9

spirochete

Answer 9

sprial, flexible

Question 10

how doe bacterial cells divide

Answer 10

by binary fission

Question 11

process of binary fission

Answer 11

during each cell division cycle, the cell has to replicate its chromosomes.
- then by the process of binary fission, the large cell forms a division septum with half of the cytoplasm and its components as well as one copy of the genetic information on either side of the cell.
- the septum is completed, and the cell divides into two identical daughter cells through cell separation.

Question 12

the process of cell division leads to what of the bacterial population

Answer 12

amplification – cells produced overtime increases in a logarithmic manner.

Question 13

what can we calculate from the bacterial growth curve

Answer 13

the generation time for cells dividing by binary fission

Question 14

what does the generation time mean

Answer 14

the time it takes for the population number to double.

Question 15

what are the 4 stages of the bacterial growth curve

Answer 15

1. lag phase, 2. log phase, 3. stationary phase, 4. death/decline phase.

Question 16

lag phase

Answer 16

–prior to completing cell division, when bacterial cells are introduced into fresh new environment to promote growth. – right now no increase in number of living bacterial cells.

Question 17

log phase

Answer 17

when cells recognize they have been provided with food, they grow in size and transition to log phase.
– when bacterial cells are the most sensitive to antibiotics.
– the time when disease symptoms develop in an infected person
- time most bacteria are continually growing and dividing
- exponential increase in number of living cells.

Question 18

stationary phase

Answer 18

• plateau in number of living bacterial cells because all food is gone.
• rate of cell division and death are roughly equal.

Question 19

death/decline phase

Answer 19

exponential decrease in number of living bacterial cells.

Question 20

a typical prokaryotic cell – draw

Answer 20

Question 21

gene expression in bacterial cells

Answer 21

on DNA strand we have mRNA strands that have been transcribed. On each mRNA, there are multiple ribosomes that synthesize the proteins. these ribosomes are called poly ribosomes or polysomes because they can be translating a single mRNA at the same time.

Question 22

what does the ‘S’ in the 30S, 50S… stand for

Answer 22

svedberg units – measure of a particle size based on its sedimentation rate

Question 23

small subunit of ribosome – its components

Answer 23

30S – 21 proteins and 1 piece of 16S rRNA

Question 24

large subunit of ribosome – its components

Answer 24

50S – 31 proteins – 2 pieces of 5S rRNA and 23S rRNA

Question 25

bacterial genome

Answer 25

chromosome or 'nucleoid' is highly organized -- if it wasnt, it would be a great tangled ball that cannot be separated and copied.