35. How thymine dimer mutations are repaired after UV damage (see notes on light
repair and excision repair)
Give this one a try later!
a. Light repair
i. DNA photolysase cleaves the bonds between thymine dimers.
ii. photolysase is an enzyme that is light-sensitive.
iii. It detects abnormal pyrimidine binding T's and C's which include thymine
dimers
b. Excision repair
i. excise mutations by a series of enzymes. Remove incorrect bases and
add correct ones.
6. Differentiate mRNA vs tRNA vs rRNA
Give this one a try later!
, a. mRNA (messenger)
i. transports the DNA master code to the ribosome
ii. contains codes for sequence of amino acids in protein
b. rRNA (ribosomal)
i. forms the major part of a ribosome and participates in protein synthesis
c. tRNA (transfer)
i. brings amino acids to ribosomes during translation
d. miRNA (micro)
i. regulation of gene expression and coiling of chromatin
ii. contains codes for regulatory RNAs
5. Microbicidal vs microbiostatic drugs and which one is preferred and why?
Give this one a try later!
a. Microbicidal: killing microbes (preferred)
b. Microbiostatic: inhibiting microbes
18. Differentiate Inducible vs repressible operon
Give this one a try later!
a. Inducible
i. The operon is normally in the OFF mode
ii. Operons encode enzymes that act in catabolism
iii. The operon is only turned on by a nutrient in the environment
1. Enzymes encoded by operon are only present when nutrient is present
2. Ex lactase is only expressed when lactose is present
b. Repressible
i. operon is normally in the ON mode
, ii. contains genes coding for anabolic enzymes
1. synthesizes amino acids
iii. several genes in a series are turned off by the product synthesized by
the enzyme
1. ex when too much of the amino acid is made, the genes needed to make
more AA are turned off
31. The methods for determining microbial susceptibility to chemotherapeutic agents,
such as the Disk Diffusion assay, E-test, tube dilution assay) Know how to interpret the
Kirby-Bauer Disk Diffusion assay. (E-Test)
Give this one a try later!
b. E-test
i. Has a strip that contains different concentrations of drug
ii. Helps to determine the minimum amount of the drug needed to inhibit
the growth of the pathogen
31. The methods for determining microbial susceptibility to chemotherapeutic agents,
such as the Disk Diffusion assay, E-test, tube dilution assay) Know how to interpret the
Kirby-Bauer Disk Diffusion assay.
(tube dilution assay)
Give this one a try later!
c. Tube dilution assay
i. MIC: the smallest concentration (highest dilution) of drug that visibly
inhibits growth
1. Useful in determining the smallest effective dosage of drug
2. Provides a comparative index against other antimicrobials
3. In clinical laboratories, these tests are performed by automated
machinery
ii. Drugs are diluted in series
iii. Inoculate and incubate
, iv. Look for growth (MIC)
v. The dilution of the first tube in the series that shows no growth is the MIC
34. Describe the different types of mutations (missense, point, silent, frameshift,
nonsense, back-mutation) and be able to identify them from a given DNA sequence.
(Convert DNA to mRNA to amino acid sequences and then compare with the original
sequence to determine if it is a missense, silent, etc.)
Give this one a try later!
a. Point mutation
i. Small mutations that affect only a single base on a gene
ii. Involve addition deletion or substitituion of single bases
1. Effects may be missense, nonsense, silent
iii. GCC-GCT
b. Lethal mutation
i. Mutations that lead to cell dysfunction or death
c. Neutral mutations
i. Produce neither adverse nor helpful changes
d. Missense mutation
i. Any change in the code that leads to a placement of a different amino
acid
ii. Ex serine > glycine
e. Nonsense mutation
i. Changes a normal codon into a stop codon that doesn't code for an
amino acid
ii. Ex serine > stop codon
f. Silent mutation
i. Alters a base but does not change the amino acid and has no effect
ii. The redundancy of code assures that certain amino acids will not be
altered by a change in the 3rd base of the codon
iii. CCU (proline) > CCC (proline)
g. Back mutation
i. Occurs when a gene that has undergone a mutation reverses to its
repair and excision repair)
Give this one a try later!
a. Light repair
i. DNA photolysase cleaves the bonds between thymine dimers.
ii. photolysase is an enzyme that is light-sensitive.
iii. It detects abnormal pyrimidine binding T's and C's which include thymine
dimers
b. Excision repair
i. excise mutations by a series of enzymes. Remove incorrect bases and
add correct ones.
6. Differentiate mRNA vs tRNA vs rRNA
Give this one a try later!
, a. mRNA (messenger)
i. transports the DNA master code to the ribosome
ii. contains codes for sequence of amino acids in protein
b. rRNA (ribosomal)
i. forms the major part of a ribosome and participates in protein synthesis
c. tRNA (transfer)
i. brings amino acids to ribosomes during translation
d. miRNA (micro)
i. regulation of gene expression and coiling of chromatin
ii. contains codes for regulatory RNAs
5. Microbicidal vs microbiostatic drugs and which one is preferred and why?
Give this one a try later!
a. Microbicidal: killing microbes (preferred)
b. Microbiostatic: inhibiting microbes
18. Differentiate Inducible vs repressible operon
Give this one a try later!
a. Inducible
i. The operon is normally in the OFF mode
ii. Operons encode enzymes that act in catabolism
iii. The operon is only turned on by a nutrient in the environment
1. Enzymes encoded by operon are only present when nutrient is present
2. Ex lactase is only expressed when lactose is present
b. Repressible
i. operon is normally in the ON mode
, ii. contains genes coding for anabolic enzymes
1. synthesizes amino acids
iii. several genes in a series are turned off by the product synthesized by
the enzyme
1. ex when too much of the amino acid is made, the genes needed to make
more AA are turned off
31. The methods for determining microbial susceptibility to chemotherapeutic agents,
such as the Disk Diffusion assay, E-test, tube dilution assay) Know how to interpret the
Kirby-Bauer Disk Diffusion assay. (E-Test)
Give this one a try later!
b. E-test
i. Has a strip that contains different concentrations of drug
ii. Helps to determine the minimum amount of the drug needed to inhibit
the growth of the pathogen
31. The methods for determining microbial susceptibility to chemotherapeutic agents,
such as the Disk Diffusion assay, E-test, tube dilution assay) Know how to interpret the
Kirby-Bauer Disk Diffusion assay.
(tube dilution assay)
Give this one a try later!
c. Tube dilution assay
i. MIC: the smallest concentration (highest dilution) of drug that visibly
inhibits growth
1. Useful in determining the smallest effective dosage of drug
2. Provides a comparative index against other antimicrobials
3. In clinical laboratories, these tests are performed by automated
machinery
ii. Drugs are diluted in series
iii. Inoculate and incubate
, iv. Look for growth (MIC)
v. The dilution of the first tube in the series that shows no growth is the MIC
34. Describe the different types of mutations (missense, point, silent, frameshift,
nonsense, back-mutation) and be able to identify them from a given DNA sequence.
(Convert DNA to mRNA to amino acid sequences and then compare with the original
sequence to determine if it is a missense, silent, etc.)
Give this one a try later!
a. Point mutation
i. Small mutations that affect only a single base on a gene
ii. Involve addition deletion or substitituion of single bases
1. Effects may be missense, nonsense, silent
iii. GCC-GCT
b. Lethal mutation
i. Mutations that lead to cell dysfunction or death
c. Neutral mutations
i. Produce neither adverse nor helpful changes
d. Missense mutation
i. Any change in the code that leads to a placement of a different amino
acid
ii. Ex serine > glycine
e. Nonsense mutation
i. Changes a normal codon into a stop codon that doesn't code for an
amino acid
ii. Ex serine > stop codon
f. Silent mutation
i. Alters a base but does not change the amino acid and has no effect
ii. The redundancy of code assures that certain amino acids will not be
altered by a change in the 3rd base of the codon
iii. CCU (proline) > CCC (proline)
g. Back mutation
i. Occurs when a gene that has undergone a mutation reverses to its
