MICRO 302 Lecture pt 2

All photolytic reactions that capture light energy to create chemical energy will also release free oxygen (O2).

False

Bacteriorhodopsin uses light energy to remove electrons from water, releasing free oxygen and generating a proton motive force.

False

Both Archaea and Bacteria use sigma factors to bind to a promoter and control multiple genes (in operons).

False

Carbohydrates make better antigens than proteins - all other variables being equal.

False

Cell mediated immunity can be transferred in convalescent serum.

False

Glycolysis requires both a membrane and oxygen as the terminal electron acceptor.

False

If Nirenberg's lab had put in poly-T instead of poly-U, they still would have seen cell-free translation of a chain of phenylalanine.

False

If looking at a polyribosomal complex, the longest peptide chains are those on the ribosomes next to the Shine Dalgarno sequences.

False

If you don't know the cause of a disease, you could most successfully use intraspecific quorum sensing inhibitors to treat their infection (by reducing the toxin gene production)

False

Immune tolerance means that the immune system can tolerate low levels of some viruses and other pathogens, but not others.

False

Most chemicals (e.g. Ethidium bromide) or processes (UV) used to induce mutations are specific to a region of DNA.

False

Standard conditions are those that are normally seen in living cells.

False

The prevalence of a disease is the number of new cases over a given time period.

False

The type of attenuation seen in the trp and his operon in E. coli is also commonly seen in eukaryotes.

False

You can get COVID_19 from the mRNA vaccine because it can change your DNA.

False

Macrophages are the most numerous and first to arrive leukocyte (upon an inflammatory signal).

false

Members of a polyphyletic group are more closely related than members of a monophyletic group.

false

One of the biggest disadvantages of subunit vaccines (like the flu vaccine) is that they can revert to virulent forms and cause the disease they were designed to prevent.

false

Perforin and granzyme are both virulence factors that cancer cells release to kill nearby cells.

false

Skin is for the most part uniform as a micro-environment, so most people have similar bacteria on their hands, face, and torso.

false

When growing in culture, E. coli uses the most glucose when it is ____.

fermenting glucose

The Reductive TCA cycle will ___.

fix carbon dioxide and cost reducing power

Intercalating agents (like ethidium bromide) will typically cause ___.

frameshift mutations

You would expect the terminal electron acceptor to ______ (for any form of respiration).

have a higher Eo than NADH

A community with an overgrowth of 1-2 species and very little else would be described as having ___.

high abundance but low species richness

Cytokines provide communication between white blood cells (leukocytes) and the body and ___.

increase blood cell development in the bone marrow, serve as chemoattractants for other leukocytes , kill target cells , activate other leukocytes to release other cytokines and proliferate

If you touch a doorknob and then your face, you may pick up cold or flu viruses. This type of transmission is ___.

indirect fomite

If tryptophan levels are low, a ribosome will slow at the leader sequence (because there are 2 trp codons in this region). This will ___.

keep the RNA polymerase on the DNA

A person with gut dysbiosis (e.g. IBD, Clostridium) typically has ____ than someone without gut dysbiosis.

less microbial diversity in their gut

Tetanus bacteria generally grow in a puncture wound, releasing toxins that act at a distance in the body (i.e. lockjaw). The bacteria, however stay in one place. This is a ____ infection.

localized

ALL enzymes work by ___.

lowering the energy of activation of a chemical reaction

The enzyme found in tears and saliva that breaks down peptidoglycan is ___.

lysozyme

The Pfizer and Moderna vaccines are both ___.

mRNA vaccines

Strong promoters differ from weak promoters because they ____.

match the consensus sequence for the sigma factor better

Which type of -omic study looks at the expression of genes within the entire community, not a single species?

metatranscriptomics

A pathogen with an LD50 of 100 is ___ virulent compared to a pathogen with an LD50 of 1000.

more

If you make a toxin with the A domain from pertussis toxin and the B domain from botulism toxin, this new toxin would target ___.

nerve cells/the neuromuscular junction (like botulism)

You find a bacterial strain that cannot use lactose because it has a stop codon in the middle of its lacZ gene that is not normally there. This mutation is a ___.

nonsense mutation

Once the complement cascade is complete, a target cell has been labeled for leukocytes, and those leukocytes will be drawn to the site by chemo attractants. What do we call this labeling (making the target cell easier to engulf)?

opsinization

Homologous sequences that have the same (or very similar) function in different sequences are called ____.

orthologs

Both chemolithotrophs and chemoorganothrophs ____.

oxidize reduced molecules to make chemical energy (ATP)

The leaves of a plant and all the microbes coating them are part of the ___.

phylosphere

Which of the following allow a pathogen to stick to a host cell?

pili or fimbriae ,capsules (on bacteria) ,adhesins (on bacteria) ,spike proteins (enveloped viruses)

The fact that there are thousands of alleles for HLA- A means that the major histocompatibility complex (MHC I) is ____.

polymorphic

Nutrients you eat that you don't digest that feed your gut microbiota are ___.

prebiotics

removing all the autoinducers from the culture media would____.

prevent quorum-sensing regulated genes from being expressed

Which component of PCR gives the process specificity?

primers

Which of the following genetic features is found in the DNA, but not RNA or protein?

promoter

In fermentation, NADH is the electron donor and ____ is the electron acceptor.

pyruvate

Nitrogenase is an enzyme complex that ___.

reduces atmospheric nitrogen

All biosynthetic reactions require ____.

reducing power, energy via APT, essential elements

If a molecule of glucose was sent through glycolysis and the TCA cycle, the carbons would be found ___.

released as carbon dioxide

Genes are NOT regulated by turning off and on their ____.

replication

Which of the following genes would you expect to see on the chromosome, but not on a plasmid?

ribosomal RNA genes

The molecule that recognizes changes in the extracellular environment is called the ______ in a 2-componet system.

sensor kinase

DnaK is a protein that ___.

serves as a sigma factor for GroEL , Not Selected binds to RpoH to prevent heat shock protein production , Not Selected Correct answer: more than one of these is correct re-folds damaged/denatured proteins , Not Selected replicates DNA in thermophiles

Which form of horizontal gene transfer requires a temperate phage to move DNA around?

specialized transduction

Both anaerobic respiration and fermentation ____.

take place without oxygen

If you were to analyze the DNA from a plant cell's chloroplasts, you'd expect it to be most similar to ____.

the DNA of a cyanobacterial chromosome

Agrobacterium species are used ___.

to add DNA to plants

Cellular respiration generates a proton motive force, so requires a membrane.

true

In the U-tube experiment, if gene transfer occurred when the filter was shut, the researchers would conclude cell-cell contact was not necessary for genes to be transferred.

true

You find a mutant bacterial strain that does not grow on minimal media, but will grow if you supplement the media with tryptophan. You would call this strain a ___.

tryptophan auxotroph

Pure fermentors may run their ATPase molecules backwards, which will ____.

use ATPase to make a proton motive force

The growth rate of microbes in nature ___.

varies greatly

Microbes that are transmitted from mother to offspring directly are transmitted ____.

vertically

If you put your gene of choice in a pUC plasmid (in the LacZ gene's multi-cut site) and transform E. coli with your plasmid, the colonies that likely have your insert will be ____ on Xgal IPTG plates.

white

Streptokinase is an enzyme made by Streptococcus bacteria. This enzyme will ___.

break clots to allow bacteria to move

Cell mediated immunity can be transferred in convalescent serum.

false

Exotoxins are only found in Gram positive cells, while endotoxins are only found in Gram negative cells.

false

If tryptophan is available in the environment, you would expect to see the Trp operon genes transcribed and translated, so they can use this amino acid.

false

Glycolysis will yield _____ATP (net) that is made by ____.

2: substrate-level phosphorylation

How much energy (in the form of high-energy phosphate bonds) does it cost to make a short (200 amino acid) peptide?

602

A signal-blind mutant is one that lacks ___.

Autoinducer receptors

If you wanted the strongest (highest affinity) antibodies (for developing anti-sera), you'd want to gather serum from your test animals ___.

at least 5 days after a challenge (late in the process)

Anoxygenic photosynthesis uses ___ as an electron donor and ___ to generate a PMF.

H2S:cyclic photophosphorylation

Which antibody isotype (class) is commonly found on mucous membranes?

IgA

If you needed to isolate nitrogen fixing bacteria from soil, you should culture your soil sample on media __.

Lacking nitrogen (ammonia) in normal air

ALL cells with a nucleus have ___.

MHC I

CD 4+ T cells will recognize antigen that is presented on ___.

MHC II

You find 2 molecules (from the Mars rover samples). Molecule A has an Eo of 0.5 V and Molecule B has an Eo of -0.3. Which molecule would be the electron acceptor if these molecules were in an electron tower.

Molecule A

Electrons released in glycolysis and the TCA cycle are carried to the electron transport chain on ____.

NADH

Most pathogens will reduce their virulence when they are in a population for many generations. This is called __.

balanced pathogencity

If RNAse had prevented the transformation of R cells to S cells in the Avery experiment, but DNAse and protease did not, the researchers would have concluded ____.

RNA is the genetic material

The SOS response is triggered by ______.

RecA binding to single stranded DNA

A phylotype is

a group of organisms that share a common ortholog (e.g. nitrogenase)

Which nucleotide could you label to measure replication, without measuring transcription?

Thymine

Activated CD8+ T cells will kill the antigen presenting cells that activate them.

True

As nutrients and amino acids become scarce, the concentration of uncharged tRNAs increases.

True

Enzymes will typically have an optimum pH and temperature.

True

Glycolysis is a mostly amphibolic pathway, meaning most of the enzymes can work in catabolism and anabolism.

True

In general, diseases with a higher Ro will need more of the population immune for that population to achieve herd immunity.

True

Slow growing species are the easiest to isolate with enrichment cultures

True

Strains of bacteria with a loss of function (lof) mutation in DNA polymerase I will typically have more mutations than wild type bacteria.

True

The new variants of COVID-19 that are appearing are examples of changes in the pathogen side of the disease triangle.

True

The process by which a molecule loses electrons is oxidation.

True

A person with allergies (e.g. hayfever) would likely have an elevated ____ count on a CBC and differential blood count.

basophil and mast cell

You are studying a new sigma factor (SigmaXYZ) and find it binds to 4 different promoters, and each of these promoters controls the expression of 2-3 genes. You would describe this system as the ____.

XYZ regulon

A change in the DNA of the promoter of the lac operon causes a significant increase in beta galactosidase expression. Is this a mutation?

Yes, it is a change in DNA

When the stringent response is triggered, which genes are turned on?

amino acid biosynthesis

Which proteins add the amino acids to the 3' end of a tRNA?

amino acyl tRNA synthetases

If a protein binds to DNA and increases expression of a nearby gene or operon, that protein is ___.

an activator

Autotrophs get their carbon from ____.

carbon dioxide

If you add arginine to culture media where E. coli have actively been making their own arginine, the transcription and translation of the arginine biosynthesis genes will be drastically reduced. In this situation, arginine acts as a(n) ____.

co-repressor

The fact that the genetic code is degenerate, but different species "preferentially" use different codons is describe as that species ___.

codon bias

You are studying 2 different microbial communities. Community #1 has 400 new species collected when you collect 1000 samples and when you collect 2000 samples, you find 402 new species. Community #2 has 300 new species when you collect 1000 samples, and 500 new species when you collect 2000 samples. Which community is more diverse?

community 2

Genes that are not regulated at the level of transcription or translation are ____ expressed.

constitutively

ALL forms of PCR will ____.

copy DNA

C3H/HEJ mice are not as responsive to LPS vs other mice because they have ___.

defective TLR4s

The wobble position most directly contributes to the genetic code's ____.

degeneracy

The one part of central metabolism that doesn't provide carbon intermediates for biosynthesis is ___.

electron transport

All organisms need reducing power for biosynthesis. This provides ____

electrons

A cytokine storm is a beneficial immune response that activates immunity to a given pathogen.

false

Adding bacteria to a toxic spill is a form of bioremediation called biostimulation.

false