Ap Biology Chapter 17 Test

Front 1

Transcription

Back 1

The making of RNA from DNA

Front 2

Translation

Back 2

Decodes an mRNA message into a protein

Front 3

Steps of Transcription

Back 3

DNA unwinds and hydrogen bonds break, A DNA strand acts as a template while the other is dorment

Front 4

What are the three basic steps of translation

Back 4

Initiation
Elongation
Termination

Front 5

Codon

Back 5

groups of three mRNA bases on mRNA

Front 6

Anticodon

Back 6

The three-base sequence on tRNA that base pairs with the codon on mRNA

Front 7

mRNA

Back 7

takes DNA message to ribosomes

Front 8

rRNA

Back 8

makes up ribosomes

Front 9

tRNA

Back 9

carries amino acid to the ribosome... it contains the anticodon

Front 10

Promoter

Back 10

DNA sequence where transcription starts- where RNA polymerase attaches and initiates transcription. It decides which strand of DNA is the template

Front 11

Transcription initiation complex

Back 11

when transcription factors recognize and bind to the promoter before RNA polymerase II can attach. It becomes transcription initiation complex.

Front 12

RNA polymerase

Back 12

Attaches and initiates transcription ... it untwists the double helix and binds to promoter

Front 13

snRNP

Back 13

small nuclear ribonucleoproteins... composed of proteins and small nuclear RNA ... they make up spliceosomes which snip out introns and exons.

Front 14

TATA box

Back 14

recognition sequence... is upstream from the start point

Front 15

template strand

Back 15

acts as a pattern for mRNA

Front 16

Coding strand

Back 16

lies dorment and is not used in protein synthesis.

Front 17

Ribozyme

Back 17

rna molecules which act as enzymes.

Front 18

intron

Back 18

long segments of noncoding base sequences... they occur within the boundaries of eukaryote genes

Front 19

exon

Back 19

expressed regions which code for proteins.

Front 20

snRNA

Back 20

small nuclear RNA make up spliceosomes and forms complexes with proteins to form snRNPs- small nuclear ribonucleoproteins... which are involved in splicing

Front 21

Posttranscriptional processing

Back 21

before mRNA can go to cytoplasm, it undergoes this... the removal of introns and splicing together of exons.

Front 22

Wobble

Back 22

phenomenon which enables the third nucleotide of some tRNA anticodons to pair with more than one kind of base codon.

Front 23

aminoacyl-tRNA synthetase

Back 23

attached to appropriate tRNA molecule to create an aminoacyl tRNA. Hydrolysis of ATP drives the process

Front 24

Polyribosome

Back 24

several ribosomes in strings

Front 25

spliceosome

Back 25

molecular complex-snips an intron out of the RNA transcirp and connects adjoining exons

Front 26

nonsense mutation

Back 26

when point mutation changes an amino acid codon into a stop codon, halting translation prematurely

Front 27

mutation

Back 27

changes in genetic information of a cell that may involve large portions of a chromosome or affect just one base pair of nucleotides

Front 28

silent mutation

Back 28

base-pair substitutions in thrid nucleotide that does not change amino acid translation

Front 29

missense mutation

Back 29

substiution that results in an incorrectly coded amino acid.

Front 30

frameshift mutation

Back 30

insertion or deletion that are not in multiples of three nucleotides which alters the reading frame.

Front 31

restriction enzymes.

Back 31

produced by bacteria to defend against attacking viruses. They destroy DNA of viruses by cutting DNA into pieces and will only cut at very specific sites on the DNA

Front 32

one gene-one polypeptide theory

Back 32

the metabolic pathway of each class was blocked at a different enzymatic step

Front 33

genetic transformation

Back 33

change caused by genes and it involves insertion of gnenes into an organism in order to change the organism's traits.

Front 34

selection

Back 34

the CFP gene is located on a plasmid as well as on the agar since it contains ampicillin. this is known as selection since we are selecting only those that have been transformed to grow

Front 35

gene regulation

Back 35

pGLO- the gene is regulated by arabinose which starts the transcription process. The genes are turned on when arabinose is present and off when it is not present

Front 36

phage

Back 36

virus that infects bacteria

Front 37

Beadle and Tatum experiment

Back 37

grew nutritional mutants that could not grow on the minimal medium that sufficed for wild-type mold. they identified the specific metabolic defect for each mutant. The metabolic pathway of each class was blocked at a different enzymatic step.

Front 38

Reading frame

Back 38

starts at start coon and reads each triplet sequentially

Front 39

initiation step of translation

Back 39

small subunit binds to mRNA and an initiator tRNA carrying methionine, which attaches to the start codon. Initiation factors and expenditure of GTP help large subunit of ribosome attaches to small one, forming translational initiation complex. The initiator tRNa fits into the p site.

Front 40

Elongation of Translation

Back 40

Proteins called elongation factors add amino acids... there are three steps...
Codon recognition... amino-acyl tRNA basepairs with mRNA codon in A-site. This requires energy from two GTP.
Peptide Bond Formation step:...an RNA molecule of large subunit catalyzes formation of peptide bond between carboxyl end of polypeptide and is held in the p site and amino acid in A site. the polypeptide is now held by the amino acid in the a-site.
Translocation...tRNA carrying the growing polypeptide is translocated to the p-site is moved to the e-site and is released. the next mRNA codon moves to the A-site as the mRNA moves through the ribosome

Front 41

Termination of translation

Back 41

occurs when a stop codon - uaa, uag, or uga reaches a-site of ribosome. a release factor binds to the stop codon and hydrolyzes the bond between the polypeptide and the tRNA in the p-site. The completed polypeptide leaves through the exit tunnel of the large subunit. the two ribosomal subunits and other components dissociate.

Front 42

Genetic code

Back 42

made of twenty amino acids and can make 64 codons. it is universal... same for all organisms... three mRNA bases code for one amino acid. Redundancy ccurs since similar codons have the same amino acid result.

Front 43

in beadle and tatum's study of Neurospora, they were able to identify three classes of mutants that needed arginine added to minimal media in order to grow. the production of arginine includes the following steps: precursor to ornithine to citrulline to arginine. What nutrient(s) had to be supplied for the mutants with a defective enzyme for the precursor to ornithine step to grow?
a. precursor only
b. ornithine only
c. citrulline only
d. ornithine or citrulline
e. precursor, ornithine, and citrulline

Back 43

d. ornithine or citrulline

Front 44

transcription invoolves the transfer of info from
a. dna to rna
b. rna to dna
c. mrna to an amino acid sequence
d. dna to an amino acid sequence
e. the nucleous to the cytoplasm

Back 44

a. dna to rna

Front 45

rna polymerase....
a.is the protein responsible for the production of ribonucleotides
b. is the enzyme that creates hydrogen bonds between nucleotides on the dna template strand and their complementary rna nucleotides.
c. is the enzyme that transcribe exons but does not transcribe introns
d. is a ribozyme composed of snRNPs.
e. begins transcription at a promoter sequence and moves along the template strand of DNA, elongating an RNA molecule in a 5 proime to three prime direction.

Back 45

e. begins transcription at a promoter sequence and moves along the template strand of DNA, elongating an RNA molecule in a 5 proime to three prime direction.

Front 46

how is the template strand for a particular gene determined?
a.it is the dna strand that runs from the five prime to three prime direction
b. it is the dna strand that runs from the three prime to five prime direction
c. it depends on the orientation of rna polymerase, whose position is determined by particular sequences of nucleotides within the promoter.
d. it doesn't matter which strand is the template because they are complementary and will produce the same mRNA
e. the template strand always contains the TATA box.

Back 46

C. it depends on the orientation of rna polymerase, whose position is determined by particular sequences of nucleotides within the promoter.

Front 47

which enzyme synthesizes tRNA?
a. rna replicase
b. rna polymerase
c. aminoacyl-tRNA synthetase
d. ribosomal enzymes
e. ribozymes

Back 47

b. RNA polymerase

Front 48

Which of the following is true of RNA processing?
a. exons are excised before the mRNA is translated
b. the RNA transcript that leaves the nucleus may be much longer than the original transcript.
c. assemblies of protein and snRNPs, called spliceosomes, may catalyze splicing.
d. large quantities of rRNA are assembled into ribosomes.
e. signal peptides are added to the five prime end of the transcript.

Back 48

c. assemblies of protein and snRNPs, called spliceosomes, may catalyze splicing.

Front 49

which of the following is not involved in the formation of a eukaryotic transcription initiation complex?
a. TATA box
b. transcription factors.
c. snRNA
d. RNA polymerase II
e. promoter

Back 49

c. snRNA

Front 50

A prokaryotic gene 600 nucleotides long can code for a polypeptide chain of how many amino acids (at most)?
a. 100
b. 200
c. 300
d. 600
e. 1800

Back 50

b. 200

Front 51

All of the following are transcribed from DNA except:
a.exons
b. introns
c. tRNA
d. rRNA.
e. promoter

Back 51

e. promoter

Front 52

what might introns have to do with the evolution of new proteins.

a. the excised introns are transcibed and translated as new proteins by themselves
b. introns are more likely to accumulate mutations than exon, and these mutations then result in the production of novel proteins.
c. introns that are self-excising may also function as hydrolytic enzymes for other processes.
d. introns provide more area where crossing over may occur (without interfering with the coing sequences) and thus increase the probability of exon shuffling between alleles.
e. introns often correspond to domains in proteins that fold independently and have specific functions. Changing domains between nonallelic genes could produce novel proteins.

Back 52

d. introns provide more area where crossing over may occur (without interfering with the coing sequences) and thus increase the probability of exon shuffling between alleles.

Front 53

A ribozyme is:
a. an exception to the one gene-one RNA molecule axiom.
b. an enzyme that adds the five prime cap and poly-A tail to mRNA.
c. an example of rearrangement of protein domains caused by RNA splicing.
d. an RNA molecule that functions as an enzyme.
e. an enzyme that produces both small and large ribosomal subunits.

Back 53

d. an RNA molecule that functions as an enzyme

Front 54

All of the following would be found in a prokaryotic cell except:
a. mRNA
b. rRNA
c. simultaneous transcription and translation
d. snRNA
e. RNA polymerase.

Back 54

the answer is d. snRNA is not found in prokaryotes because prokaryotes don't go through post-RNA processing.

Front 55

which of the following is transcribed and then translated to form a protein product?
a. gene for tRNa.
b. intron
c. gene for a transcription factor
d. five prime and three prime untranslated regions
e. gene for rRNA

Back 55

c. gene for a transcription factor.

Front 56

transfer RNA.
a. forms hydrogen bonds between its codon and the anticodon of an mRNA in the A site of a ribosome.
b. binds to its specific amino acid in the active site of an aminoacyl-tRNA synthetase.
c. uses GTP as the energy source to bind its amino acid
d. is translated from mRNA
e. is produced in the nucleolus.

Back 56

b. binds to its specific amino acid in the active site of an aminoacyl-tRNA synthetase.

Front 57

place the following events in the synthesis of a polypeptide in the proper order
1. a peptide bond forms
2. an aminoacyl tRNA matcfhes its anticodon to the codon in the a-site
3. a tRNA translocates from the A to the P site, and an unattached tRNA leabes the ribosome from the E site.
4. The large subunit attaches to the small subunit, with the initiator tRNA in the P site.
5. A small subunit binds to an mRNA and an initiator TRNA.
a. 45321
b. 45213
c. 54321
d. 54123
e. 54213

Back 57

e. 54213

Front 58

Translocation in the process of translation involves
a. the hydrolysis of a GTP molecule.
b. the movement of the tRNA in the A site to the P site.
c. the movement of the mRNA strand one triplet length
d. the release of the unattached tRNA from the E site
e. all of the above.

Back 58

e. all of the above

Front 59

which of the following type of molecule catalyzes the formation of a peptide bond?

a. RNA polymerase
b. rRNA
c. mRNA
d. aminoacyl-tRNA synthetase
e. protein ribosomal enzyme

Back 59

b. rrna

Front 60

which of the following is not true of an anticodon
a. it consists of three nucleotides
b. it lines up in the five prime to three prime direction along the five prime to three prime mRNA strand.
c. it extends from one loop of a trna molecule.
d. it may pair with more than one codon.
e. its base uracil base-pairs with adenine.

Back 60

b. it lines up in the five prime to three prime direction along the five prime to three prime mRNA strand.

Front 61

Several proteins may be produced at the same time from a single mRNA by
a. the action of several ribosomes in a string, called a polyribosome
b. several RNA polymerase moleculesworking sequentially.
c. signal peptides that associate ribosomes with rough Er.
d. containing several promoter regions.
e. the involvement of multiple spliceosomes.

Back 61

a. the action of several ribosomes in a string, called a polyribosome.

Front 62

A signal peptide
a. is most likely to be found on cytosolic proteins produced by bacterial cells
b. directs an mRNA molecule into the cisternal space of the ER.
c. is a sign to help bind the small ribosomal unit at the initiation codon
d. would be the first twenty or so amino acids of a protein destined for a membrane location or secretion from the cell
e. is part of the five prime cap.

Back 62

d. would be the first twenty or so amino acids of a protein destined for a membrane location or secretion from the cell

Front 63

A base deletion early in the coding sequence of a gene may result in.

a. nonsense mutation
b. frameshift mutation
c. multiplle missense mutations.
d. a nonfunctional protein.
e. all of the above

Back 63

e. all of the above

Front 64

base-pair substitutions may have little effect on the resulting protin for all of the following reasons except which one?

a. the redundancy of the code may result in a silent mutation.
b. the substitution must involve three nucleotide pairs, otherwise the reading frame is altered
c. the missense mutation may not occur in a critical part of the protein
d. the new amino acid may have similar properties to the replaced one.
e. the wobble phenomenon could result in no change in translation.

Back 64

b. the substitution must involve three nucleotide pairs, otherwise the reading frame is altered

Front 65

A mutation results in a defective enzyme a. In the following simple metabolic pathway, what would be a consequence of that mutation?
A------enzyme a------------>B-----------enzyme B------> C

a. an accumulation of A and no production of B and C
b. an accumulation of A and B and no product. of C
c. an accumulation of B and no production of A and C
d. an accumulation of B and C and no production of A
e. an accumulation of C and no production of A and B

Back 65

a. an accumulation of A and no production of B and C

Front 66

A portion of the genetic code is UUU=phenylalanine, GCC= alanine, AAA=lysine, and CCC= proline. Assume the correct code places the amino acids phenylalanine, alanine, and lysine in a protein (in that order). which of the following DNA sequences would substitute proline for alanine?
a. AAA-CGG-TTA
b. AAT-CGG-TTT
c. AAA-CCG-TTT
d. AAA-GGG-TTT
e. AAA-CCC-TTT

Back 66

d. AAA-GGG-TTT

Front 67

a particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is
a.TTT
b.UUA
c.UUU
d.AAA
e. Either UAA or TAA, depending on wobble in the first base

Back 67

c. UUU

Front 68

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5 prime CCG-ACG 3 prime
The following activated transfer RNA molecules are available. Two of them can correctly match the mRNA so that a dipeptide can form.

tRNA anticodon Amino Acid
GGC Proline
CGU Alanine
UGC Threonine
CCG Glycine
ACG Cysteine
CGG Alanine

The dipeptide that will form will be:
a. cysteine-alanine
b. proline-threonine
c. glycine-cysteine
d. alanine-alanine
e. threonine-glycine

CGG

Back 68

b. proline-threonine

Front 69

This figure represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine). Which of the following triplets of bases on the mRNA strand codes for this amino acid?

5' GAA 3'

a. UGG
b. GUG
c. GUA
d. UUC
e. CAU

Back 69

d. UUC

Front 70

Each of the following is a modification of the sentenct
THECATATETHERAT

a. THERATATETHECAT
b.THETACATETHERAT
c.THECATARETHERAT
d.THECATATTHERAT
e.CATATETHERAT
Which of the above is analogous to a frameshift mutation?
a, b, c, d, or e?

Back 70

d

Front 71

What is the relationship amond DNA, a gene, and a chromosome?
a. a chromosome contains hundreds of genes, which are composed of protein.
b. a chromosome contains hundreds of genes, which are composed of DNA
c. A gene contins hundreds of chromosomes, which are composed of protein
d. a gene is composed of DNA, but there is no relationship to a chromosome
e. a gene contains hundreds of chromosomes, which are composed of DNA

Back 71

b. a chromosome contains hundreds of genes, which are composed of DNA

Front 72

Each of the following is a modification of the sentence.
THECATATETHERAT
a.THERATATETHECAT
b.THETACATETHERAT
c.THECATARETHERAT
d.THECATATTHERAT
e.CATATETHERAT

which of the above is analogous to a single substitution mutation?
a, b, c, d, or e?

Back 72

c

Front 73

How is the template strand for a particular gene determined?
a. it is the DNA strand that runs from the five prime to the three prime direction.
b. it is the DNA strand that runs from the three prime to five prime direction.
c. it depends on the orientation of RNA polymerase, whose position is determined by particular sequences of nucleotides within the promoter.
d. it doesn't matter which strand is the template because they are complementary and will produce the same mRNA.
e. the template strand always contains the TATA box.

Back 73

b. it is the DNA strand that runs from the three to five prime direction.