Microbio review 1 Flashcards

When did Earth begin to become oxygenated and what group of organisms were responsible for this?

In the tree of life, Eukarya are more closely related to Bacteria than Archaea.

Which is NOT an appropriate example of a microorganism and the domain of life that it belongs to?

Everything that is smaller than 1 mm is considered a microorganism

Which of the following is NOT considered a microorganism?

What are the 5 main functions an organism must have in order to be considered a “living organism"?

What functions are viruses missing that consider them to be a “non-living organism?”

How do viruses fit into the domain of life

Antonie van Leeuwenhoek was the first to build the microscope, with a resolution 0.2 μm, in 1676. What kinds of organisms can you see with a 0.2 μm resolution?

If you are in a lab looking at bacterial cells under a microscope with an ocular lens of 10x and with a 40X objective lens, what is the total magnification of the microscope field?

In order to see bacterial cells underneath a microscope, scientists may have to prep samples with dye in order to see cell morphology and internal structures. However, some organisms already contain molecules that help us see them. What are some examples of these molecules?

During times of nutrient deprivation, cells are found to get smaller in response to this. Why would cells want to decrease their cell size in a nutrient deficient state opposed to increasing their cell size?

You are a student in the lab accessing your gram stain results from a soil sample that you collected from the campus pond. Upon looking into the microscope you see many purple clustered circular cells. What can you conclude from these results?

Gram negative bacteria are surrounded by two layers of _________, between which lies the cell wall. Fill in the blank

Many different organisms will produce a cell wall made out of various types of molecules in certain configurations. Based on the different types of cell walls we talked about in class, which type has the strongest structure in terms of rigidity and preventing cell lysis?

Peptidoglycan is made of two different sugars—N-acetylglucosamine (G) and N-acetylmuramic acid (M), and has four different amino acid attachments. One chain (sugar backbone G-M-G-M) is connected via _______ and cross-links to another chain via _______.

What components of bacterial cells differ from eukaryotic cells?

What components of eukaryotic cells differ from bacterial cells?

Instead of having intracellular transport mechanisms, bacterial cells are able to move nutrients, molecules, ect. via ________?

Bacteria have circular chromosomes that are compacted via supercoiling and Eukaryotes have linear chromosomes that are compacted via histone proteins.

Plasmids are “extrachromosomal” meaning that they contain extra DNA that bacteria can incorporate into their chromosomes to gain functions. What are some examples of functions bacteria can gain from plasmids?

When a bacterial cell is passing a plasmid over to another bacterial cell this process is done via _________?

In the central dogma of genetic information flow DNA is __________ to RNA and then __________ to protein

The enzyme RNA polymerase is responsible for making a RNA transcript while using DNA a “blueprint”. Where in the DNA does RNA polymerase dock onto to start this process?

What genetic components are found in eukaryotic cells but not in bacterial cells?

Bacteria are able to encode for multiple genes in one mRNA polycistronic transcript. What is the area in the DNA called where this transcript is transcribed from?

In Bacteria and Eukarya, transcription and translation are a simultaneous process that happens in the cytoplasm

Quorum sensing is a mechanism that allows bacteria to sense how many bacteria are around them. Why would this be important for many bacterial species?

During times of nutrient exhaustion, bacteria may have an operon, or cluster of genes, that they can express to process alternative nutrients. This operon is expressed only in the presence of the alternative nutrients

Some species have to activate specific activator proteins or sensor kinases that trigger transcription of specific genes. Many species are only able to achieve this

What are the steps in order that are involved in biofilm formation?

During attachment and colonization, what genes are NOT upregulated/downregulated in biofilm forming bacteria

Why are biofilms beneficial for many bacterial species

While biofilm formation can be beneficial for the bacterial organisms, it can be extremely problematic in human settings such as hospitals. What is NOT a reason why biofilms may be problematic in a hospital setting?

During times of extreme stress, some bacteria are able to adapt by differentiating into a new cell type known as endospores with often completely different characteristics. This is a non-reversible process that is considered a survival mode for many bacterial species

Heterocysts are

The chemical reaction that turns N2 gas into ammonia is oxygen sensitive. What are some ways that heterocysts combat this in oxygen producing cyanobacteria?

example of anabolism

What kind of organisms will you most likely not find in soils

Planting legumes that have root nodule-forming bacteria can save farmers from purchasing fertilizers because the bacteria

Decomposition in the soil is initiated by microorganisms that are

The main primary producers in the surface ocean of tropical and subtropical latitudes are

Microbial mats in the surface sediments around deep sea hydrothermal vent systems are mainly composed of