Lecture 13- Archaea and Bacteria Flashcards
Microbiome definition
Community of microorganisms that inhabit a particular environment or organism, playing a crucial role in various biological processes.
bacterial colony definition
Visible cluster of bacterial cells that have grown and multiplied on an agar plate.
Enrichment culture definition
a growth of bacteria where there are certain conditions that enrich bacteria w/ certain qualities
Steps to enrichment cultures
- Environmental sample with many types of cells
- Culture the sample
- Select specific environment conditions (temp, salt, nutrients, etc)
- Isolote the cells that grow rapidly
The goal of enriching cultures
detect and obtain cells with specific characteristics
Difference in characteristics between archaea and bacteria
bacteria have peptidoglycan in the cell wall while archaea don’t
Extremophiles definition
organisms that THRIVE in high-salt, high-temp, low-temp, or high-pressure environments
Why are tardigrades not considered extremophiles?
They endure extreme conditions, not thrive in them.
How to comment on the diversification of bacteria and archaea?
- Genetic variation
- morphological diversity
- metabolism
Lateral gene transfer allows for the acquisition of diverse traits which include:
- transformation
- transduction
- conjugation
Transformation definition
bacteria or archaea naturally take up DNA from the environment released by cell lysis or secreted
Transduction definition
viruses pick up DNA from one prokaryotic cell and transfer it to another cell
Conjugation definition
genetic information transferred by direct cell to cell contact- includes an event called plasmid transfer
Process of DNA transfer by transformation
- dead cell releases DNA into the environment
- New DNA incorporated into living cell by recombination
Process of DNA transfer by transduction
- Bacteriophage infects host which produces phages with both viral and bacterial DNA
- Bacteriophage injects donor DNA into the recipient bacterial cell.
Process of recombination via conjugation
- portion of main chromosome is copied and transferred through conjugation tube to recipient cell
- transferred portion of chromosome recombines with chromosome in recipient cell
Plasmid transfer via conjugation
- two bacterial cells come into contact. one cell contains plasmid
- copy of plasmid is transferred from donor cell to recipient cell through a conjugation tube
how can genetic variation can translate to morphological diversity
- Varied size
- Varied Shape
- Varied motility
Gram positive definition
- most cells dye purple
- contain peptidoglycan cell wall
Gram negative definition
- most cells dye pink
- contain two cell walls sandwiching a peptidoglycan layer
Fundamental needs of organisms
- Acquire chemical energy
- obtain molecules with C-C bonds
Autotrophs definition
C-C bonds Self synthesized from CO2, CH4, or other simple molecules
Heterotrophs
C-C bonds from molecules produced by other molecules
Phototrophs
energy acquisition from sunlight
