BIO5 - Microbiology Flashcards
Do all niches on the planet harbor microorganisms?
Yes
Name the three groups of microorganisms
Microorganisms are viruses, prokaryotes (bacteria and archaea), eukaryotes (fungi, algae, etc.)
How do bacteria proliferate (multiply)?
Bacteria reproduce by asexual duplication. Meaning a single bacteria cell divides into two with identical genome.
How is the bacterial growth rate calculated
What do bacteria and Archaea have in common (as opposed to eukaryotes)
As opposed to eukaryotes, bacteria and archaea are prokaryotes, meaning that they do not have membrane-bound organelles such as a nucleus, mitochondria, or the endoplasmic reticulum within their cells.
How can CO2 absorption in the ocean be facilitated?
It has been postulated that a good way to facilitate CO2 absorption in the oceans would be to facilitate algae growth. One way of doing this could be to simply add iron to the ocean. However, there is quite a lot of research that shows this would not be a good idea. It has therefore been proposed that adding glacial rock flour could be a sustainable alternative.
(The absorption of carbon dioxide by the ocean can be facilitated by Emiliania huxleyi, a species of marine algae that uses photosynthesis to produce energy. During a specific stage in its life cycle, E. huxleyi incorporates CO2 into its calcium carbonate shell (coccoliths), effectively capturing carbon dioxide.)
What are (some of the) adverse effects of microorganisms?
Microorganisms can have a lot of adverse effects ranging from food spoilage to Covid-19.
Name some (biotechnological) uses of microorganisms
We use microorganisms to produce drugs and other technology, to enhance foods (resistance, growth rate, GMOs). We use yeast for wine and beer production and create this yeast with biotechnology.
What is meant by synthetic biology?
Synthetic biology is the science of redesigning biological organisms for useful purposes, by engineering them to have new abilities, or creating new ones from scratch
How can one determine the abundance of microorganisms in a niche?
To determine the abundance of microorganisms in a niche, researchers typically use methods such as:
Culturing Techniques: Growing microorganisms on selective media to isolate and count viable cells.
Molecular Techniques: Using techniques like quantitative PCR (qPCR) or digital droplet PCR to quantify specific microbial DNA.
Metagenomics: Analyzing genetic material directly from environmental samples to assess the diversity and abundance of microorganisms without the need for culturing.
Microscopy: Counting cells using fluorescent microscopy or flow cytometry after staining with specific dyes.
How can one determine the functions of microorganisms in a niche?
The functions of microorganisms in a niche can be determined through:
Metagenomic Sequencing: Identifying genes present in microbial communities that indicate metabolic capabilities and potential functions.
Functional Assays: Measuring specific activities, such as nutrient cycling (e.g., nitrogen fixation, carbon degradation) through biochemical assays.
Transcriptomics: Analyzing RNA expression profiles to understand which genes are actively being expressed under certain conditions.
Proteomics: Studying the protein composition of microorganisms to identify functional roles in biochemical pathways.
How do bacteria evolve (so rapidly)?
Because of their exponential growth, bacteria experience many generations in short amounts of time. I.e. a lot of mutations happen, diversifying their genepool. This is especially effective if they have environmental stress or other selective pressures. Furthermore, bacteria can directly exchange genetic material through horizontal transfer.
What is the advantage of heterogeneity in a microbial population?
Heterogenity leads to increased resilience in the population. Furthermore, it allows the individual organisms to perform specialized tasks, increasing colony efficiency.
Why can rRNA gene be used as a phylogenetic marker of all life?
The rRNA gene (especially the 16S rRNA gene in prokaryotes and 18S rRNA in eukaryotes) is an effective phylogenetic marker because:
Highly Conserved: rRNA genes are conserved across all domains of life, making them suitable for studying evolutionary relationships.
Presence in All Organisms: All living organisms have ribosomal RNA, allowing for comparisons across different life forms.
Variable Regions: The rRNA gene contains both conserved and variable regions, enabling researchers to distinguish between closely related species and assess broader evolutionary relationships.
Name one disadvantage and one advantage of bacterial biofilms
Advantage: Enhanced Survival: Biofilms provide a protective environment for bacteria, making them more resistant to environmental stresses, such as desiccation, antibiotics, and immune responses.
Disadvantage: Challenging Treatment: Bacterial biofilms can be difficult to eradicate in clinical settings, leading to persistent infections and complications in medical device-related infections.
