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Review 6 Flashcards

1
Q

VIRAL Genetic Material

A

May be linear or circular DNA or RNA

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2
Q

Packaging DNA Supercoil in Prokaryotes

A

DNA GYRASE uses ATP to twist circular molecule into a supercoil

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3
Q

DEGENERATIVE CODE

A

More than one series of three nucleotides that code for an amino acid

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4
Q

UNAMBIGUOUS CODE

A

Any three nucleotides will code for one and only one amino acid

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5
Q

UNIVERSAL CODE

A

Almost every living organism uses the same code

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6
Q

Primer

A

A Primer is a small chain of RNA produced by RNA Polymerase called PRIMASE

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7
Q

Helicase

A

Unwinds the double helix separating two strands

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8
Q

Replisomes

A

BI-DIRECTIONAL replisomes proceed in BOTH directions

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9
Q

Topoisomerase

A

Cut one or both of the strands and unwrap the helix, releasing the excess tension
a. when helicase unwinds the helix at the origin, DNA gets wound more tightly upstream and downstream

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10
Q

Types of Prokaryotes Polymerase

A
  1. Pol 3 - Fast accurate elongation of the leading strand and Proofreading 3’ to 5; exonuclease activity correct mistakes by removing incorrect nucleotides
  2. Pol 2 - unknown
  3. Pol 1 - Removes primer and replaces it with DNA
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11
Q

Removal of RNA primers in prokaryotes and Eukaryotes

A

Prokaryotes - Pol 1

Eukaryotes - RNase H

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12
Q

Deletions

A

When a portion of a chromosome breaks off

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13
Q

Duplications

A

DNA fragments break free from one chromosome and incorporate into another

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14
Q

Aneuploidy

A

When a chromosome is copied

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15
Q

Polyploidy

A

When entire sets of chromosomes are copies

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16
Q

Translocation

A

Segment of DNA from one chromosome is inserted into another chromosomes

Transposons: excise themselves from a chromosome and reinsert themselves at another location

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17
Q

Proofreading

A

DNA polymerase checks its work and excises incorrectly matched bases.

daughter strand is identified by its lack of methylation and corrected accordingly.

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18
Q

Mismatch Repair

A

Occurs during the G2 phase of the cell cycle, using the genes MSH2 and MLH1.

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19
Q

Nucleotide Excision Repair

A

Fixes helix-deforming lesions of DNA (such as thymine dimers) via a cut-and-patch process that requires an excision ENDONUCLEASE

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20
Q

Base Excision Repair

A

Nondeforming lesions of the DNA helix (such as cytosine deamination) by removing the base, leaving an apurinic/apyrimidinic (AP) site.

AP EXONUCLEASE then removes the damaged sequence, which can be filled in with the correct bases

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21
Q

CONSENSUS SEQUENCE

A

Variations from the consensus sequence cause RNA polymerase to bind LESS tightly and LESS often to a given promoter causing the gene to be transcribed LESS

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22
Q

RNA Polymerase

A
  1. Pol 1 - rRNA
  2. Pol 2 - mRNA
  3. Pol 3 - tRNA
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23
Q

RNA Polymerase NOTE

A

NO proofreading activity, HIGH rate of errors

24
Q

REGULATION NOTE

A

Most happen in REPLICATION

25
LAC Operon
POSITIVE control system
26
TRP Operon
REPRESSION system produces enzyme for the production of Trp. INACTIVATED by the presence of Trp, repressor protein is ACTIVATED in the presence of trp. POSITIVE CONTROL SYSTEM
27
Peptide Bond in translation
Enzimatically attaches the two amino acids together,creating a peptide. Process is repeated until the polypeptide is complete
28
ATP Requirement for AA loading on TRNA
2 ATP
29
Prokaryote Ribosome
50S + 30S = 70S
30
Eukaryote Ribosome
60S + 40S = 80S
31
ATP/GTP Requirement for initiation
1 ATP/GTP
32
ATP/GTP Requirement for elongation
1 ATP/GTP
33
ATP/GTP Requirement for translocation
1 ATP/GTP
34
Pleiotropy
Alteration of a gene alters many different, unrelated aspects of the organism's total phenotype
35
Polygenism
Traits that are influenced by many different genes Example: Height is influenced by genes for growth factors, receptors, hormones, bone deposition, muscle...
36
Penetrance
The likelihood that a person with a given genotype will express the expected phenotype
37
Epistasis
Expression of alleles for one gene is dependent on a different gene. Example: A gene for curly hair cannot be expressed if a different gene causes baldness.
38
Nondisjunction
Sometimes homologous chromosomes fail to seperate during meiosis I and sometimes during meiosis II sister chromatids fail to separate. The result is gametes with two copies or no copies of a given chromosome.
39
Test cross
To deduce the genotype of a individual, cross it with a HOMOZYGOUS RECESSIVE
40
POPULATION
Individuals that are able to REPRODUCE with each other
41
Gene Pool
The sum total of all genetic information in a population
42
NOTE about Natural Selection
Natural selection DOES NOT introduce | genetic diversity, it acts on existing diversity to alter allele frequencies.
43
DIRECTIONAL NATURAL SELECTION
If natural selection removes one extreme, the population average over time will move in the other direction. Example: Giraffes get taller as all short giraffes die for lack of food. LOOK AT THE GRPAH FROM HANDOUT
44
DIVERGENT NATURAL SELECTION
Natural selection removes the members near the average, leaving those at either end. Example: Small deer are selected for because they can hide, and large deer are selected because they can fight but mid-sized deer are too big to hide and too small to fight.
45
STABILIZING NATURAL SELECTION
Both extremes are selected against, driving the population to the average
46
SPECIES
A group of organisms capable of MATING with each other and can produce viable reproductive offspring
47
ALLOPATRIC ISOLATION
Diverging of species due to geographic isolation
48
SYMPATRIC ISOLATION
One species gives rise to a new species in the same geographical area
49
HOMOLOGOUS STRUCTURES
Are physical features shared by two species that are a result of a common ancestor ex- bat wings, human hand, dogs paw and whale flipper all had a common ancestor
50
ANALOGOUS STRUCTURES
Serve the same function in two species but not common ancestors ▪ ex- birds wing and butterfly wing
51
CONVERGENT EVOLUTION
When two species come to possess analogous structures due to similar selective pressures. Ex-bat and bird wings
52
DIVERGENT EVOLUTION
Selection causes a species to branch out to many species
53
BINOMIAL CLASSIFICATION
Genus species
54
7 Taxonomical Categories
``` Kingdom Phylum Class Order Family Genus Species ```
55
7 Taxonomical Categories Acronym
King Philip Came Over For Great Sex

MCAT Miscellaneous (17 decks)

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