Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Genetics > 12| THE GENETIC CODE AND TRANSCRIPTION > Flashcards

12| THE GENETIC CODE AND TRANSCRIPTION Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Term that explains why multiple codons can code for a single amino acid

A

wobble hypothesis

  • Crick; occurs because that base has been chemically modified; redundancy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  • like DNA Poly in many ways
  • only difference is the strand, ribosenucleotides
  • and no primer required

describes what term

A

RNA Polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The sequence, TATAAT, which is an essential part of a promoter site on DNA for transcription to occur in bacteria is termed

A

pribnow box

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Molecules that bind to DNA elements

a. cis-acting
b. trans-acting

A

trans-acting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Genetic Code is….

name seven

A

1- Unambiguous (one triplet specifies one amino acid)
2 -Degenerate (redundancy, mostly at 3rd base)
3 -Commaless
4 -Nonoverlapping
5 -Universal ( recombinant DNA technology, exceptions to universal-ness are at the wobble base)
6 -Linear (ribonucleotide bases, composing mRNA as letters)
7 - Initiates and terminates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Some amino acids are specified by more than one codon, only tryptophan and methionine are coded by single codons.

This can be termed as… (think about the genetic code and what it is)

A

2 -Degenerate (redundancy, mostly at 3rd base)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the three termination (stop) codons?

A

UAG, UAA, UGA)

-They do not code for any amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When does initiation of transcription begin…

A

Signals in DNA indicate to RNA polymerase where it should start and end transcription.

These signals are special sequences in DNA that are recognized by the RNA polymerase or by proteins that help RNA polymerase determine where it should bind the DNA to start transcription.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Transcription Start Site, where transcription begins is achieved how….

A

Once RNA polymerase explores the length of DNA and recognizes the promoter region

  • Transcription begins when RNA polymerase binds to a promoter sequence. RNA polymerase uses othe template strand to make a new, complementary RNA molecule.
  • Transcription ends in a process called termination.
    ie: 3’—Promoter located —- initiator sequence (transcription begins)——————————— termination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Refers to sequences located toward the 5’ end of the coding strand…..

-promoter located here

A

Upstream

-downstream refers to the 3’ end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Encodes more than one related proteins, can be termed as a…

-genes in bacteria are called cistrons

A

polycistronic message

-euk have Monocistronic mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

T or F a single tRNA contains a single Anticodon?

A

T

-during translation codons pair with anticodons which allows the correct AA to be linked to a given codon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where might you find overlapping genes?

A

in viruses

ie: OX174 phage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

T or F there are different reading frames in different tissues

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

During RNA synthesis, this enzyme cleaves off triphosphate from the DNA template

A

RNA Polymerase

  • the initial step in gene expression is the synthesis under the direction of RNA polymerase from a strand of RNA complementary to a DNA template strand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Enzyme responsible for directing synthesis

A

RNA Polymerase

  • the initial step in gene expression is the synthesis under the direction of RNA polymerase from a strand of RNA complementary to a DNA template strand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The four main enzymes involved in transcription….

A

RNA poly

DNA PI, PII and PIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The three main enzymes involved in translation….

A

aatRNA
GTP Realease Factor
Peptidyl transferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

assembly of amino acids, DETERMINES SPECIFIC CHARACTERISTICS of the higher order of orginization

a. primary
b. secondary
c. tertiary
d. Quaternary

A

primary

  • “STRUCTURE”
  • single chain——> alpha / Beta —-> packed to a protein —-> oligometric macromolecule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

FOLDING of the alpha helix and beta sheets. H- between back bone to stabalize.

a. primary
b. secondary
c. tertiary
d. Quaternary

A

secondary

“FOLDING”

  • correct folding is dependent on chaperone proteins
  • single chain——> alpha / Beta —-> packed to a protein —-> oligometric macromolecule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Packaging 3D single unit related to the specific FUNCTION of any protein

a. primary
b. secondary
c. tertiary
d. Quaternary

A

tertiary

  • “FUNCTION”
  • single chain——> alpha / Beta —-> packed to a protein —-> oligometric macromolecule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Interacting macromolecule with more then 1 AA/ PP chain (combination of subunits)

a. primary
b. secondary
c. tertiary
d. Quaternary

A

Quaternary

  • single chain——> alpha / Beta —-> packed to a protein —-> oligometric macromolecule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

when beta pleated sheets of hemoglobin are altered as a result from a single AA change the result is

A

sickle cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What direction is the polypeptide chain…

“temis”

A

amino (N+) termis ——–> Carboxyl (C-) termis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What does a functional ribosome contain during elongation? ….. name four

A

mRNA
charged tRNA
monosome
peptidyl transferase

26
Q

“Elongation factors”, during translation in the ribosome

A

Elongation Factors = GTP (Mg 2+)

27
Q

Carries the AA (Anticodon) in translation

A

tRNA

28
Q

Roles of proteins…..

A

Enzymes (Biochemical reactions, metabolism), transport, structure, receptors, hormones, immunity

29
Q

a polymer made by reaction of two different monomers, with units of more than one kind….

A

Copolymer

-repeating sequences, to repeating triplets;
UG ————> UGU or GUG
UUG————> UUG, UGU or GUU
UAUG ————> UAU, CUA, UCU or AUC

-use of the triplet binding assay and repeating copolymers determined specific sequence triplet codons designating specific amino acids.

30
Q

What would you use if you wanted to force RNA into artificial synthesis

A

rNDPs, ribonucleoside diphospates

31
Q

Translation or Transversion;

a. pyrimidine replace and pyrimidine
b. purine replaces pyrimidine

A

translation (pyrimidine replace and pyrimidine).

transversion (purine replaces pyrimidine).

32
Q

– bind DNA, interfere with replication and repair. Can lead to cancer.

– component in cigarette smoke, heterocyclic amines, chard burgers. Chemically mutagenetic, mustard gas, Ethylmethyl Sulfonate (EMS)

termed;

a. Acridine Dyes
b. Adduct forming agents

A

Adduct forming agents

33
Q

– chemical mutagen dyes (colors) affecting positively/ negatively the bases

  • results in frameshift (side by side mutation)

a. Acridine Dyes
b. Adduct forming agents

A

Acridine Dyes

34
Q

How does repair recognize which strand is correct template and which contains the incorrect base?

A

the unmethylated strand after excision, it is temporarily unmethylated post replication

35
Q

Induced point mutations

-Result from influence of an extraneous functions

name five ways point mutations can be induced

A
  1. ionizing radiation – xrays, gamma rays, cosmic rays
    - penetrate deep tissue
    - form free radicals;
    - can break phosphodiester bond
    - result in point mut. And break 2. 2.chromosomes
    - radiation therapy; affects offspring
  2. UV- shorter (higer E) wavelengths more damaging
    - effect pyrimidine dimers, adj. thymidine residue
  3. Alkylating Agents
  4. Base Analogs
36
Q

Spontaneous point mutations can occur naturally

  • From replication errors and as modifications, normal biological/ chemical processes
A
  1. Depurination vs Demiation -base pairing keto
  2. Transposons
  3. Replication Error- slippage
  4. Oxidative damage
  5. Tautomeric Shift- spontaneous, loss of 1 nuc. Affects H- affinity. Base pairing change T=G, C+A

6.

37
Q

a type of Spontaneous point mutation that Disrupts reading frame. Byproducts/ free radicals/ exposure to high-energy.

A

Transposons

-Spontaneous point mutations can occur naturally

38
Q

What type of point mutation is being described by the following

  • HOT SPOTS: some DNA sequences are more susceptible to mutagen
  • SEQUENCE DEPENDENT
A

Spontaneous point mutations

-can occur naturally and have a variable rate genome to genome

39
Q

Elements that can move with in a genomes reading frame creating mutation and altering expression of genes. They may contribute to evolution and are used in genetic research such as cloning…

A

Transposons

-A transposable ELEMENT is a DNA sequence that can change its position within a genome, sometimes creating or reversing mutations and altering the cell’s genetic identity and genome size. Transposition often results in duplication of the same genetic material

40
Q

________ like transposons also move by a “copy and paste” mechanism but in contrast to the transposons described above, this copy is made of RNA, not DNA. The RNA copies are then transcribed back into DNA

A

Retrotransposons (defined as the same thing as transposons)

-A transposable ELEMENT is a DNA sequence that can change its position within a genome, sometimes creating or reversing mutations and altering the cell’s genetic identity and genome size. Transposition often results in duplication of the same genetic material

41
Q

Not all genetic traits become apparent at the same time during an organism’s life span. in most cases, the age at which a mutant gene exerts a noticeable phenotype depends on events during the normal sequence of growth and development. Ie Tay Sachs and huntingtons (expressed 30-50 yo), DMD (3-5 yo)

can be termed as

A

onset of genetic anticipation

-while genetic anticipation is the phenomenon where by a genetic disorder is passed onto the next generation at an earlier age with each generation. In most cases with an increase in severity is also noted.

42
Q

A final example involving genetic background is called _______, whereby the process of selective gene SILENCING occurs during early development. Impacting subsequent phenotypic expression.

A

Imprinting

-(aka genomic Imprinting or parental Imprinting )

43
Q

The proportion of mtDNA molecules that determines both the penetrance and severity of expression of some diseases….

A

Heteroplasmy

44
Q

Term that referes to a cell that has a uniform collection of mtDNA: either completely normal mtDNA or completely mutant mtDNA

A

Homoplasmy

45
Q

Also known as an abasic sites, this is a location in DNA that has neither a purine nor a pyrimidine base, either spontaneously or due to DNA damage.

A

an APURINIC (AP) site

46
Q

These point mutations can range from NEUTRAL or SILENT to LOSS or GAIN of FUNCTION to lethality

A

autosomal or X-linked

-not the same as somatic/ germ line mutations which occur in the body or the x and y linked regions

47
Q

Not affected by natural selection

a. mutations (may or may not alter structure or fx)
b. polymorphisms (discontinuous genetic variation resulting in the occurrence of several different forms or types of individuals among the members of a single species. A discontinuous genetic variation divides the individuals of a population into two or more sharply distinct forms.)

A

b. polymorphisms (discontinuous genetic variation resulting in the occurrence of several different forms or types of individuals among the members of a single species. A discontinuous genetic variation divides the individuals of a population into two or more sharply distinct forms.)

48
Q

affected by natural selection

a. mutations (may or may not alter structure or fx)
b. polymorphisms (discontinuous genetic variation resulting in the occurrence of several different forms or types of individuals among the members of a single species. A discontinuous genetic variation divides the individuals of a population into two or more sharply distinct forms.)

A

a. mutations (may or may not alter structure or fx)

49
Q

Three types of polymorphisms are…

-polymorphisms (discontinuous genetic variation resulting in the occurrence of several different forms or types of individuals among the members of a single species. A discontinuous genetic variation divides the individuals of a population into two or more sharply distinct forms.)

A
  1. SNP, single nucleotide polymorphism
  2. CNV, Copy number variation
  3. Epigenetics (Chemical modifications in enviroment)
    - polymorphisms (discontinuous genetic variation resulting in the occurrence of several different forms or types of individuals among the members of a single species. A discontinuous genetic variation divides the individuals of a population into two or more sharply distinct forms.)
50
Q

The four subcategories of point mutations…

-a single base pair change

A
  1. somatic/ germline
  2. induced - base analogs/ alkylating agents
  3. spontaneous- can be naturally occuring (hot spots)
  4. autosomal/ x-linked - neutral or silent, loss or gain
51
Q

Loss-of-function (complete loss of function)

a. null mutations
b. dominant mutations
c. haploinsuficancy
d. frame shift mutations (side by side mutation)

A

null mutations

  • dominant mutations and haploinsuficancy are a gain-of-function

dominant mutations-non functioning product inactivates wild-type

haploinsuficancy - results in enhanced, reduced, or new functions

52
Q

INSERTIONS OR DELETIONS, the most devastating mutation types cab happen at the stop codon, the earlier in the frame the worse

a. null mutations
b. dominant mutations
c. haploinsuficancy
d. frame shift mutations (side by side mutation)

A

frame shift mutations (reading frame shift; side by side mutation)

  • dominant mutations and haploinsuficancy are a gain-of-function. null mutations are Loss-of-function

dominant mutations-non functioning product inactivates wild-type

haploinsuficancy - results in enhanced, reduced, or new functions

53
Q

Name the repair mechanism

The enzymes, error rate is 1:100,000 bp

A

proofreading repair - exonuclease

54
Q

Name the six type of repair mechanism and there method…

A
  1. proofreading repair - exonuclease
  2. miss-match repair - recognized, excised, DNA poly fills in the gap
  3. post replicational repair - recA protein, recombinational exchange
  4. post replicational repair - SOS
  5. Light Damage Repair - reduced dimers
  6. Excision and Repair - cut out, DNA poly replaces, ligase seals
             a. base repair - glycolysis
         b. nucleotide repair - Pi+base
55
Q

Xeroderma Pigmentosum in Humans, the patients were deficient in DNA synthesis and this repair mechanism led to increased insight into this condition….

A
  1. Excision and Repair - cut out, DNA poly replaces, ligase seals
    b. nucleotide repair - Pi+base, dimers and gap fill
56
Q

Self splicing RNAs attract specific _______ RNA to the splicosome

A

snRNAs

-Self splicing RNAs include; ribozymes (Catalytic not in humans?), splicosomes and consensus sequences (near intron/exon junction)

57
Q

Different combinations within exons of the same gene that can be brough together to make isoforms (different related protein products) …

a. Self splicing RNAs
b. alternative splicing

A

alternative splicing

-Self splicing RNAs include; ribozymes (Catalytic not in humans?), splicosomes and consensus sequences (near intron/exon junction)

58
Q

phenotypes recorded by counting whole numbers Ie hens eggs

a. meristic trait
b. threshold trait
c. continuous trait

A

meristic trait

59
Q

a small number of discrete (discontinuous traits) phenotypic classes; environmental factors cause like DM II

a. meristic trait
b. threshold trait
c. continuous trait

A

threshold trait

60
Q

If true breading P1 generation is always homozygous (red x white) and the F1 generation is pink, the F1 will have an expanded phenotype pool closer or away from the mean range?

A

closer or Regresed towards the middle

Genetics (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions