MicroExam 2 (Edited)

mother cells

original cells that start the process of division

daughter cells

identical genetic cell copies of mother cells

cell division

when a single cell splits into 2 or more cells (how they grow and reproduce)

binary cells

two identical cells

budding

makes small “baby” cell that grows before detaching- common in yeasts

lag phase

bacteria are adjusting to their environment (little to no growth)

log phase

rapid cell division leading to exponential growth (where bacteria grows fastest)

stationary phase

nutrients are developed (growth slows down, rate of new cells=cell death)

decline (death phase)

more cells die than reproduced

cell mass

measure how cloudy a culture is (more cloudy=more bacterial cells)

cell number

count how many living cells are present

spectrophotometer

shines light through bacterial culture and measures cloudiness (turbidity)

serial dilutions

help calculate the concentration of microorganisms in the original liquid sample

hydrostatic pressure

pressure from water due to its weight

quorum sensing

how bacteria talk to each other by releasing chemical signals to work together

biofilms

groups of bacteria together on surfaces (like plaque on teeth) they create a protective layer to help them survive

prokaryotes

has only 1 chromosome (bacteria)

eukaryotes

have bigger and multiple chromosomes

genes

made up of nucleotide sequences which form RNA

central dogma of biology

transfer of genetic info

3’

where new nucleotides are added

triplet codon

3 nucleotides code for amino acid (mRNA)

AUG

start codon

UAA, UAG, UGA

stop codons

recombination

combining of genes (DNA) from 2 different cells

vertical gene transfer

when genes pass from parents to offspring

horizontal lateral gene transfer

pass genes to other microbes of the same generation

griffith

pneumococcal infections in mice

transduction

method of transferring genetic material using a bacteriophage

prions

have protein parts but no nucleus (mad cow disease)

transformation

cell absorbs and incorporates foreign genetic material from its environment through its cell membrane

naked DNA

genetic material outside of DNA

bacteriophage

virus that infects bacteria

lytic cycle

rapid replication of viral particles using the host cells machinery- pathogenic (destruction of bacterial cell)

lysogenic cycle

viral DNA is copied each time host cell divides- nonpathogenic

virulent phage

capable of causing infection and destruction and death of bacterial cell

temperate phage

does not cause disruptive infection

prophage

DNA that is incorporated into host bacteria

specialized transduction

(lysogenic cycle) phage inserts at specific location in cell

generalized transduction

(lytic cycle) phage can inject DNA anywhere in bacterial cell

conjugation

male bacteria uses long pili and connects it to female bacteria to transport DNA

lederbergs experiment

made mixture of 2 strains, and strains by themself, growth only occured with mixture of 2 strains because bacteria were conjugating

plasmid DNA

smaller circular DNA than regular DNA

F+ cels

contain plasmids (male bacteria)

F- cells

lack plasmids (female bacteria)

high frequency recombinations

part of F plasmid is transferred along with adjacent chromosomal genes (replicates more than 1000x)

transposon gene

bounded by inverted repeated terminals (can transport/jump from one place to another)

synchronous growth

all cells divide at the same time (rare)

Nonsynchronous Growth

cells divide at different times (normal in nature)

obligate aerobes

Need O₂.

Obligate Anaerobes

Killed by O₂.

Facultative Anaerobes

Can live with or without O₂

Microaerophiles

Need small amount of O₂

Aerotolerant Anaerobes

Don’t use O₂ but aren’t harmed by it.

Streak Plate Method

Spread bacteria on agar to isolate single colonies.

Pour Plate Method

Mix sample with melted agar → colonies form inside agar.

Synthetic/Defined Media

Exact chemical composition known.

Complex Media

Contains unknown components (e.g. nutrient broth, agar).

Selective Media

Promotes growth of one type, inhibits others

Differential Media

Shows visible differences (e.g., color change).

Replication

DNA makes new DNA

Transcription

DNA makes RNA as the first step in protein synthesis

Translation

RNA links amino acids together to form proteins

Reverse transcription

RNA can make DNA