Test 2 Questions Flashcards
What three enzymatic activities are required outside of the cytoplasmic membrane in order to complete peptidoglycan polymerization and insertion into the cell wall, and what are the roles of those three enzymatic activities?
Transglycosylase- Polymeries Glycan
Transpeptidase- Crosslinks peptide chains
Autolysins- Cleave existing wall to allow insertion of more PG.
BRIEFLY describe the TWO defining characteristics that differentiate Passive and Active transport.
Passive transport does not require energy, goes from high concentration to low concentration (with concentration gradient). Active transport requires energy and goes from low to high concentration (against concentration gradient).
In E. coli cells, the proteins that cause cell division to happen precisely at the cell center are called the ____ system.
Min
The sugar-rich outermost layer of Gram-negative bacterial cells is called:
LPS (lipopolysaccaride)
Peptidoglycan precursor molecules are attached to ____ while being transported across the cell membrane.
Bactoprenol
Abundant fixed protein filaments on a cell surface are called:
fimbriae
When a bacterial culture no longer has sufficient energy available for cellular repair, it will enter____phase.
death
Directional motility with respect to a chemical gradient is called:
chemotaxis
The energy source for ABC transporters is:
ATP
An organism that grows optimally at pH 3.7 is classified as a:
acidophile
The time between inoculation of a batch culture and the beginning of growth is called the _____ phase.
lag
The arrangement of flagella all over the cell surface is called:
peritrichous
Organisms that require oxygen but are killed by full atmospheric oxygen concentration are called:
Microaerophiles
During ____, a chemical is transported in the same direction as a proton.
symport
____ are the filamentous structures involved in twitching motility.
pilli
Gram-positive bacteria have _____ -linked lipids.
ester
The polymers that comprise the capsule of a bacterial cell are called:
polysaccharides
A particular growth media inhibits the growth of all gram-positive bacteria. Gram-negative bacteria that are capable of fermenting the sugars present in the media produce a visible color change while bacteria that cannot ferment the sugars produce no color change. This growth media is best described as:
1)Selective
2)Differential
3)Neither selective or differential
4)Both selective and differential
Both selective and differential