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41 Cards in this Set
- Front
- Back
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Free-living cells are called ..., while those in a biofilm are called ...
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planktonic
sessile |
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The first step in biofilm formation is that a few cells attach to a surface, they communicate with each other, and start forming a ... that prevents the cells from being washed off the surface. These initial cells form ...
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polysaccharide
microcolonies |
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Biofilms protect cells from:
1. 2. 3. |
1. phagocytosis
2. antibiotics 3. chemical disinfectants |
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... is probably the best known example of a biofilm and the formation starts with the attachment of a few cells of ...
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dental plaque
Streptococcus mutans |
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what is the cause of periodontal disease:
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As the polysaccharide layer continues to grow, a specialized micro-environment is formed. The thick plaque becomes anaerobic, so that other organisms become trapped and grow. It is these organisms which cause periodontal disease.
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Cystic Fibrosis is a genetic disease that causes mucus to build up in the lungs. Most patients die from ... infections
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Pseudomonas aeruginosa
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Most bacteria, when growing in the body, use glycolysis. This produces large amounts of ... In order for glycolysis to continue, the ... must be oxidized back to ...
There are two ways by which bacteria can do this: 1. 2. |
NADH
NADH NAD+ 1. respiration 2. fermentation |
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In respiration, the electrons from ... are passed down an electron transport chain. the electron transport chain is composed of what 3 modules:
1. 2. 3. |
NADH
1. dehydrogenase 2. quinone 3. terminal reductase |
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The ... in the electron transport chain uses oxygen to accept the electrons and the oxygen is reduced to ...
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terminal reductase
water |
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In other words, aerobes use oxygen to oxidize NADH. This produces an ... which allows ... to produce ...
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electrochemical gradient
ATPase ATP |
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One of the most common quinones used by bacteria is ... which is also know as ...
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menaquinone
vitamin K |
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Humans get their vitamin K from ... and ... Vitamin K is necessary for ... synthesis. Vitamin K deficiency reduces ... ability.
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intestinal bacteria
food prothrombin blood clotting |
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anaerobes do not have ... therefore, they use ... to oxidize the NADH back to NAD+ and have special pathways which use ... to oxidize NADH. this is the ... pathway
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electron transport chain
fermentation pyruvate fermentation |
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An operon is;
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two or more genes with the same promoter
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how many messenger RNAs are there in one operon:
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one
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Many genes and operons in bacteria are regulated and each gene in an operon starts with ... codon and ends with ... codon
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AUG
nonsense |
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induction is when:
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the external signal turns transcription on
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repression is when:
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the external signal turns transcription off
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1. what is an inducible system:
2. what is a repressible system: |
1. one where transcription is turned on by an external signal
2. one where transcription is turned off by an external signal |
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example, the lac operon codes for enzymes that use lactose as a carbon source. The genes only need to be active when lactose is present.
what type of system is this: |
inducible
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example: The trp operon codes for enzymes that make the amino acid tryptophan. The genes only need to be active when tryptophan is not present.
what type of system is this: |
repressible
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1. the small molecule signal in an inducible system is call:
2. the small molecule signal in a repressible system is called: |
inducer
corepressor |
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Regulated genes or operons have ... that either help RNA polymerase to bind to the promoter, or prevent RNA polymerase from binding.
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proteins
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In systems under positive control, the protein that regulates transcription, called ..., turns transcription on.
In systems under negative control, the protein that regulates transcription, called ..., turns transcription off. |
an activator protein
a repressor |
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The lac Operon is a ... controlled ... system
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negatively
inducible |
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In the absence of lactose, the lacI gene makes a ... protein that binds to a region of DNA called the ... and when bound, it prevents RNA polymerase from initiating transcription
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repressor
operator |
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for the lac operon, when lactose is present, it is converted into the inducer, ... which binds to the ... and inactivates it. Now the RNA polymerase can initiate transcription and transcribe the three lac genes.
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allolactose
repressor protein |
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to where does RNA polymerase bind:
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promoter
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The lac operon is ... because lactose turns it on.
It is ... controlled because the regulatory protein turns transcription off. |
inducible
negatively |
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the trp operon is a ... controlled ... system
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negatively
repressible |
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In the absence of tryptophan, the ... is made, but is ... In the presence of tryptophan, the ... is ...
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trpR repressor
inactive trp repressor active |
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The trp operon is ... because tryptophan turns it off.
It is ... controlled because the regulatory protein turns transcription off. |
repressible
negatively |
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the ara operon is a ... controlled ... system
In the absence of ..., the activator protein is made and is ... In the presence of ..., the activator protein becomes ... |
positively
inducible arabinose inactive arabinose active |
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The ara operon is ... because arabinose turns it on.
It is ... controlled because the regulatory protein turns transcription on. |
inducible
positively |
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what is an example of catabolite repression:
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when glucose turns off lac operon
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Catabolite repression ensures that the organism will use ... first and only use the other available carbohydrates when the glucose is ...
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glucose
exhausted |
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In the absence of glucose, ... converts ATP into ... This binds with a protein called CAP (Catabolite Activator Protein). This complex binds to the activator binding site and helps RNA polymerase initiate transcription at the ...
When glucose is present, it reduces the activity of ..., so less ... is made |
adenylate cyclase
cAMP promoter adenylate cyclase cAMP |
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The lac operon is positively controlled because the ... regulatory protein turns transcription on.
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CAP
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MRSA (...) strains of Staphylococcus aureus are resistant to all known ... antibiotics. This includes all penicillins, carbapenems and cephalosporins. This is because these strains have two genes that MSSA strains don’t have. One of these genes is ..., which makes a protein that breaks down ...
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methicillin resistant Staph. aureus
β-lactam blaZ β-lactam antibiotics |
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The blaZ gene is ... and ... controlled. the presence of a ... antibiotic inactivates the ...
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inducible
negatively β-lactam repressor |
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when testing for the presence of β-lactamase the culture needs to be grown with a very low level of ... this will induce the ... gene and allow the cells to produce β-lactamase. if the test is done without inducing β-lactamase, ... strains will appear to be ...
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penicillin
blaZ MRSA MSSA |
