Things to Know (Test 2)

Binary fission

Method by which most bacterial and archaeal cells reproduce. Cell replicates DNA and divides into two identical daughter cells.

Replisome

Group of proteins needed for DNA synthesis.

Chromosome partitioning

Process of separating duplicated chromosomes so each daughter cell gets one copy during cell division. Par A and Par B insure process is correct.

FtsZ protein

Forms a ring meeting at the cell’s center and helps divide the cell by guiding septum formation.

Growth

Refers to population growth rather than growth of individual cells.

Generation (doubling) time

Time required for the populations to double in size. Varies by species and environmental conditions.

Neutrophiles

Growth optimum between pH 5.5 and 8. Most bacteria and protists fall into this category.

Antimicrobial Agent

A substance that kills or inhibits the growth of microorganisms.

Conditions Influencing the Effectiveness of Antimicrobials

• Population size (Larger populations take longer to kill)

• Concentration or intensity of microbial agent

• Contact time (Longer exposure=more killed)

• Temperatures (Higher temps enhance chemical activity)

• Local environment.

Natural Control Mechanisms

• Predation, macrophages

• Toxin-mediated killing using bacteriocins

• Viral-mediated lysis using pathogen specific bacteriophage lysis.