CH 14

CH 14 HW 1

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In the diagram below, the gray unit represents ____

RNA polymerase

Which of the following would not be found in a bacterial cell?

Small RNAs in spliceosome

Which of the following is not part of the translation initiation complex?

TATA box

The tRNA shown in the figure above has its 3' end projecting beyond its 5' end. Which of the following will occur at this 3' end?

The amino acid will bind covalently.

Polypeptides are assembled from _____.

amino acids

Transfer RNA ___

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

An organism that produces light is called

bioluminescent

The type of mutation responsible for sickle-cell anemia is

both a point mutation and a nucleotide-pair substitution

What amino acid sequence does the following DNA nucleotide sequence specify? 3′−TACAGAACGGTA−5′

met-ser-cys-his

A ___________ mutation causes an early Stop codon to occur.

nonsense

The RNA that has an amino acid attached to it, and that binds to the codon on the mRNA, is called a

tRNA

Which of the following sequences shows a frameshift mutation compared to the wild-type mRNA sequence?

wild-type 5'-AUGCAUACAUUGGAGUGA-3' mutant 5'-AUGCAUACAUCUGGAGUGA-3'

Complete the following sentences. Match the words in the left column to the appropriate blanks in the sentences on the right

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No, in bacterial cells, the translation of mRNA can begin as soon as the 5 end of the mRNA molecule peels away from the DNA template. In eukaryotic cells, however, transcription and translation are separated in space and time as a result of the eukaryotyic cell`s nuclear membrane

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Ch 14 HW 2

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A stretch of bacterial DNA 600 nucleotides long can code at most for a polypeptide of how many amino acids?

200

A particular triplet of bases in the template strand of DNA is 5'-AGT-3'. The corresponding codon for the mRNA transcribed is

3'-UCA-5'.

Drag the appropriate tRNAs to the binding sites on the ribosome to show the configuration immediately before a new peptide bond forms. Note that one of the binding sites should be left empty.

E- site emptyP- site AUA with three amino acidsA- site UCC with one amino acid

The RNA segments joined to one another by spliceosomes are

exons

The flow of information in a cell proceeds in what sequence?

rom DNA to RNA to protein

of translation happens when the ribosome hits a stop codon on the mRNA.

termination

During transcription of the DNA in the figure above, where would the promoter be located?

to the right of the template strand Submit

Which of the following mutations would be MOST likely to have a harmful effect on an organism?

a single nucleotide insertion downstream of and close to the start of the coding sequence

Drag the terms on the left to the appropriate blanks on the right to complete the sentences.

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Examine the simple metabolic pathway above. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway?

2

Which of the following individuals was the first to suggest that genes dictate phenotypes through enzymes?

Archibald Garrod

How is the template strand for a particular gene determined?

It is established by the presence of the promoter.

Which enzyme synthesizes tRNA?

RNA polymerase

What name is given to the process in which pre-mRNA is edited into mRNA?

RNA processing

Where does translation take place?

Ribosome

Messenger RNA (mRNA)

carries information specifying amino acid sequences of proteins from DNADNA to ribosomes.

True or false. A tRNA with an anticodon complementary to the stop codon catalyzes the reaction by which translation is terminated.

false

CH 14 MC

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Drag the amino acid abbreviations to fill in the table. Not all labels will be used.

1: Cys 2: Ser 3: Leu

The direction of synthesis of an RNA transcript is ____

5' —> 3'

What is the correct tRNA anti-codon for the mRNA codon 5'-GCA-3'?

5'-UGC-3' The tRNA sequence 3'-CGU-5', which can also be written as 5'-UGC-3', is the correct anti-codon for the mRNA codon 5'-GCA-3'.

Using the table on the left, identify a 5′→3′5′→3′ sequence of nucleotides in the DNADNA template strand for an mRNAmRNA coding for the polypeptide sequence Cys-Gly-Leu.

5′−GAGTCCGCA−3

Which of these is currently considered the best definition of a gene?

A gene codes for either a polypeptide or an RNA molecule.

Transcription begins at a promoter. What is a promoter

A site in DNA that recruits the RNA Polymerase

Which of the following statements correctly defines the process of gene expression?

Gene expression is the process by which DNA directs the synthesis of proteins.

The initiator tRNA attaches at the ribosome's _____ site.

P

In eukaryotes there are several different types of RNA polymerase. Which type is involved in transcription of mRNA known as pre-mRNA?

RNA polymerase II

Translation occurs in the __

cytoplasm

Transfer RNA (tRNA)

serves as a translator molecule in protein synthesis; translates codons into amino acids.

Which of the following is not a post-translational modification that might be required of a protein before it becomes functional in a cell?

-Attachment of sugars to amino acids of the protein -Cleavage of a polypeptide chain -Binding of two or more polypeptide chains. -Removal of an amino acid

It can be assumed that a ribosome met a stop codon in a(n) intron(s) and translation stopped resulting in a shortened protein. In human cells introns are removed by RNA splicing before translation starts, but there is no RNA splicing in bacterial cells. Also, some part of amino acids in the resulting protein was incorrect because they had been translated from introns . This fact could cause the production of a nonfunctional protein.

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Siamese cat′′s fur is darker in the cooler parts of the skin (extremities), such as ears, nose, tail and paws. Conversely, warmer parts of the body are associated with lighter fur. The reason is that Siamese cats have a mutated tyrosinase, enzyme that produces pigment melanin. This mutant enzyme is temperature-sensitive, so the increase in the temperature decreases the activity of the tyrosinase. That is why cat′′s warm parts of the body are coated with melanin-lacking hair

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To understand this research, you must be familiar with some basic biology terminology. Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Not all terms will be used.

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Ch 14 Guided reading

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Part D - Which domain of the insulin precursor protein is affected by each SNP?Translation of the insulin mRNA produces a precursor protein of 110 amino acids, shown in the diagram below.

1. In patient 1, the SNP causes a Val 42→Gly amino acid change that is located in the: B chain 2. In patient 2, the SNP causes a Ala 74→Thr amino acid change that is located in the C peptide. 3. In patient 3, the SNP causes an Arg 55→Pro amino acid change that is located in the dibasic site. 4. In patient 4, the SNP causes a Tyr 103→stop change that is located in the A chain.

Drag the correct label to each target in the table. Labels may be used more than once.

1. yes no 2. no yes 3. yes yes 4.yes no

Using the results of your BLAST alignments, complete the table below by dragging one blue label to each blue target and one pink label to each pink target. Labels may be used once, more than once, or not at all. Answers for the example alignment presented above are included in the first row of the table as a guide.

125, T, G - top row 220, G, A

Using these additional alignments, complete the table you started in Part A.

164, G, C-top 309,C,G

Compare each patient's cDNA sequence to the wild-type cDNA sequence. Each patient has one nucleotide-pair substitution mutation. At which nucleotide location is the mutation found for each patient? Drag the numbers and letters to fill in the table. Numbers and letters may be used once, more than once, or not at all.

1: 143, T, G 2: 143, T, C 3: 147, C, G

If the sequence ATGCATGTCAATTGA were mutated such that a base were inserted after the first G and the third T were deleted, how many amino acids would be changed in the mutant protein?

2

Examine the table of codons in the figure above. A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be

3'-AAA-GAA-TAA-CAA-5'.

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5'-CCG-ACG-3' (mRNA). The charged transfer RNA molecules shown in the figure below (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form. The anticodon loop of the first tRNA that will complement this mRNA is

3'-GGC-5'.

Given the locally unwound double strand of DNA in the figure above, in which direction and on what strand does the RNA polymerase move during transcription?

3'→5' along the template strand

Life as we know it depends on the genetic code: a set of codons, each made up of three bases in a DNA sequence and corresponding mRNA sequence, that specifies which of the 20 amino acids will be added to the protein during translation. Imagine that a prokaryote-like organism has been discovered in the polar ice on Mars. Interestingly, these Martian organisms use the same DNA → RNA → protein system as life on Earth, except that there are only 2 bases (A and T) in the Martian DNA, and there are only 17 amino acids found in Martian proteins. Based on this information, what is the minimum size of a codon for these hypothetical Martian life-forms?

5 bases

Which components of the previous molecule will also be found in mRNA in the cytosol?

5' UTR E1 E2 E3 E4 UTR 3'

Examine the table of codons in the figure above. A peptide has the sequence NH2-phe-pro-lys-gly-phe-pro-COOH. Which of the following sequences in the coding strand of the DNA could code for this peptide?

5'-TTT-CCC-AAA-GGG-TTT-CCC

In the sequence alignment (Figure 1), count the number of each base at position -9. Order them from most frequent to least frequent.

7 G, 2 A, 1 C, 0 T

In the sequence alignment (Figure 1), count the number of each base at position 0. Order them from most frequent to least frequent.

8 A, 1 G, 1 T, 0 C

I ONLY MADE IT TO A ?

81.3 :(

Which of the following is transcribed and then translated to form a protein product?

A gene for a transcription factor

After transcription begins, several steps must be completed before the fully processed mRNA is ready to be used as a template for protein synthesis on the ribosomes. Which three statements correctly describe the processing that takes place before a mature mRNA exits the nucleus?

A poly-A tail (50-250 adenine nucleotides) is added to the 3' end of the pre-mRNA.A cap consisting of a modified guanine nucleotide is added to the 5' end of the pre-mRNA.Noncoding sequences called introns are spliced out by molecular complexes called spliceosomes.

Which of the following processes only occurs in eukaryotic gene expression?

A poly-A tail is added to the 3' end of an mRNA, and a cap is added to the 5' end

Which of the following statements about ribozymes is/are correct?

A ribosome can be regarded as one large ribozyme. -Ribozymes are RNA molecules that function as enzymes. -In some genes, intron RNA functions as a ribozyme and catalyzes its own excision.

Why is a frameshift missense mutation more likely to have a severe effect on phenotype than a nucleotide-pair substitution missense mutation in the same protein? Why

A substitution missense affects only one codon, but a frameshift missense affects all codons downstream of the frameshift.

At which site do new aminoacyl tRNAs enter the ribosome during elongation?

A-site

Which of the following is true of RNA processing?

Assemblies of protein and small RNAs, called spliceosomes, may catalyze splicing.

Which of these is a tRNA?

B

What determines which base is to be added to an RNA strand during transcription?

Base pairing between the DNA template strand and the RNA nucleotides

Several methods to monitor gene activity and protein distribution are available. Because the detection of intracellular GFP demonstrated in this paper requires only blue light illumination, it is not limited, like other methods, by the availability of additional molecules (i.e. substrates, enzymes, cofactors). Therefore, the use of GFP to monitor gene activity and protein distribution has many applications. Select all the potential applications of using the GFP marker as a tool.

Because GFP does not interfere with cell growth or function, it can indicate whether transformation of living cells is successful or not.Selective killing of cells could occur if GFP-expressing cells are identified and then lasered.GFP can be used as a marker in living cells to illuminate cell movement, particularly in transparent organisms like zebrafish.In large branched cells, the small size of the GFP protein can illuminate the movement of the protein throughout the cell's cytoplasm.

If the 5′ → 3′ nucleotide sequence on the nontemplate DNA strand is CAT, what is the corresponding codon on mRNA?

CAU

The tRNA anticodon, GAC, is complementary to the mRNA codon with the sequence

CUG

Which of the following terms best describes the relationship between the newly synthesized RNA molecule and the DNA template strand?

Complementary

True or false? A codon is a group of three bases that can specify more than one amino acid.

False- a codon is a group of three bases that can specify only one amino acid

This study was published in 1994 and revolutionized cell and molecular biology research. The study's authors took advantage of the green fluorescent protein's bioluminescence and developed a method to insert its ability to glow into other organisms in hopes of monitoring gene expression and protein localization. What are the key conclusions from this research? Select all that apply.

GFP transformation provides a valuable tool for monitoring gene expression and protein distribution.The eukaryotic GFP gene was successfully transformed to a prokaryotic organism (E. coli) and a eukaryotic organism (C. elegans). GFP expression does not require additional molecules such as substrates, enzymes, or cofactors.GFP expression produces a strong green fluorescence when illuminated by blue light in both prokaryotic and eukaryotic cells.

The energy required for assembly of a polypeptide by a ribosome comes directly from

GTP

Which of these correctly illustrates the pairing of DNA and RNA nucleotides?

GTTACG CAAUGC

What is the function of the release factor in translation?

It binds to the stop codon in the A site in place of a tRNA.

Which of the following statements correctly describes alternative RNA splicing?

It can allow the production of different protein products from a single mRNA

Which of the following is true of a codon?

It can be either in DNADNA or in RNARNA.

Think about the DNA coding sequence of a gene. If an A were swapped for a T, what kind of mutation could it cause and why?

It could cause a silent, missense, or nonsense mutation because those are the types that can be caused by a nucleotide-pair substitution like this one.

Which of the following is a function of a poly-A tail in mRNA?

It helps protect the mRNA from degradation by hydrolytic enzymes.

What is the effect of a nucleotide-pair substitution that results in a nonsense mutation in a gene?

It introduces a premature stop codon into the mRNA.

What happens to RNA polymerase II after it has completed transcription of a gene?

It is free to bind to another promoter and begin transcription.

What happens to the cut-out intron after alternative RNA splicing?

It is rapidly degraded.

Where does RNA polymerase begin transcribing a gene into mRNA?

It starts after a certain nucleotide sequence called a promoter.

What is the function of RNA polymerase?

It unwinds the double helix and adds nucleotides to a growing strand of RNA.

What must happen to a newly made polypeptide before it can be secreted from a cell?

Its signal sequence must target it to the ER, after which it goes to the Golgi.

A eukaryotic transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids. Which of the following statements best explains this fact?

Many noncoding stretches of nucleotides are present in eukaryotic DNA.

During translation, nucleotide base triplets (codons) in mRNA are read in sequence in the 5' → 3' direction along the mRNA. Amino acids are specified by the string of codons. What amino acid sequence does the following mRNA nucleotide sequence specify? 5′−AUGGCAAGAAAA−3′

Met-Ala-Arg-Lys

The average length of a transcription unit along a eukaryotic DNA molecule is about 27,000 nucleotide pairs, whereas an averaged-sized protein is about 400 amino acids long. What is the best explanation for this fact?

Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides that are not translated.

Part E - How does each SNP affect the targeting and processing of the insulin precursor protein?Recall that under normal circumstances, the insulin precursor protein is processed in the lumen of the ER to produce the mature (functional) insulin protein. Depending on the type of mutation produced and the protein domain affected, a SNP may have a profound effect on the structure and function of the mature insulin protein, or it may have no effect on the mature protein at all.In this exercise, you will use what you learned in the previous part to predict which domains will be present in the mature insulin protein produced by each patient. In addition, you will predict whether the insulin produced by each patient will function normally or whether the patient will exhibit some form of diabetes. For this exercise, assume that all patients are homozygous for the SNP.

Patient 1: Val 42-->Gly- B chain-A+B- unknown Patient 2: Ala 74-->Thr- C peptide-A+B- normal Patient 3: Arg 55-->Pro-dibasic site- A+B+C- diabetic Patient 4: Tyr 103-->stop-A chain- A+B+C- diabetic

Which of the following processes is an example of a post-translational modification?

Phosphorylation

Based on the logo, what five adjacent base positions in the 5' UTR region (the untranslated region at the 5' end of the mRNA) are most likely involved in ribosome binding? Explain.

Positions -12 to -8 have the tallest stacks in the 5' UTR region; therefore, they represent the most likely sequence for the ribosome binding site.

Drag each label into the appropriate bin depending on whether it applies to primary, secondary, tertiary, or quaternary structure.

Primary Structure- amino acid sequenceSecondary Structure- result from hydrogen bonding bestrewn the backbone constituens of the poly peptide, alpha helix, beta pleated sheetTertiary Structure- the overall shape of a polypeptide, results from interactions between side chains (R groups) of amino acidsQuaternary Structure- The aggregation of multiple polypeptide subunits.

A mutant bacterial cell has a defective aminoacyl-tRNA synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of the normal phenylalanine. What would be a potential consequence for a cell in which this happens? Remember that phenylalanine may be encoded by multiple codons.

Proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU.

A mutation in a cell results in a structural change in the signal-recognition particle (SRP) so that it does not bind to the translocation complex in the ER correctly. Which of the following processes will occur because of this mutation?

Proteins produced during translation that are destined for the ER will not be translocated into the ER.

Which of the following molecules are produced by transcription?

Ribozymes Messenger RNA

Use the table to sort the following ten codons into one of the three bins, according to whether they code for a start codon, an in-sequence amino acid, or a stop codon. Drag each item to the appropriate bin.

START: AUG STOP CODON: UAA, UAG, UGA AMINO ACID: THE REST

Which of the following is true of RNA splicing?

Spliceosome is an example of ribozymes.

In comparing DNA replication with RNA transcription in the same cell, which of the following is true only of replication?

The entire template molecule is represented in the product.

Which of the following steps occurs last in the initiation phase of translation?

The large ribosomal subunit joins the complex. Submit

Which of the following statements best describes the promoter of a protein-coding gene?

The promoter is a nontranscribed region of a gene.

What is meant by translocation?

The ribosome slides one codon down the mRNA

Suppose that the triplet of nucleotides indicated in bold (AGC) spans two codons, that is, CTA and GCC. If the triplet AGC were deleted from this DNA coding sequence, what effect would it have on the resulting protein? 5'-ATGCTAGCCTATCGTAAC-3'

The two flanking codons would be altered, but the rest of the amino acid sequence would be the same because there would be no frameshift.

The research findings from this study revolutionized cell biology and molecular genetics. What is the most important result of this study?Hint: Review the abstract and turn on the "Results and conclusions" learning lens in the online article and scan the highlighted portions of the paper.

This research showed that GFP expression is capable of producing light in both prokaryotic and eukaryotic cells without additional substrates, enzymes, or cofactors.

Place the labels of Group 1 in their proper locations on this diagram showing the process of transcription. Then, use the labels of Group 2 to identify the corresponding RNA nucleotide that belongs in each pink target. Labels of Group 2 can be used once, more than once, or not at all. Drag the appropriate labels to their respective targets.

Top: Nontemplate strand, RNA polymerase Middle: template strand, A,U,G,C Bottom: RNA being produced

What is the process called that converts the genetic information stored in DNA to an RNA copy?

Transcription

A eukaryotic mutation upstream of a particular gene has been identified that changes the sequence of the TATA box to GATA. How would you predict that this mutation would affect the transcription of this gene?

Transcription factor binding would be reduced or eliminated, and transcription of the gene would decrease dramatically.

Indicate at which step of the replication-transcription-translation process each type of RNA first plays a role. During which step of the replication-transcription-translation process does each type of RNA first play a role? Drag each item to the appropriate bin. (Not every bin has to be filled.)

Transcription/RNA processing: mRNATranslation: tRNA, rRNADuring replication, a faithful copy of a DNA molecule is made.During transcription, the DNA "message" is copied onto a molecule of mRNA.During translation, the information carried in the mRNA is transferred to molecules of tRNA to build a protein on the ribosomes.

Which of the following statements is correct regarding protein synthesis in prokaryotes and eukaryotes?

Translation can begin while transcription is still in progress in prokaryotes, but not in eukaryotes.

Suppose that a portion of double-stranded DNA in the middle of a large gene is being transcribed by an RNA polymerase. As the polymerase moves through the sequence of six bases shown in the diagram below, what is the corresponding sequence of bases in the RNA that is produced?

UGAGCC

The figure above represents a tRNA molecule that recognizes and binds a particular amino acid (in this instance, phenylalanine). Which codon on the mRNA strand codes for this amino acid?

UUC

In the 1920s, Hermann Muller discovered that X-rays caused genetic changes in the fruit fly Drosophila. In a related series of experiments in the 1940s, other scientists discovered that other types of chemicals have a similar effect. A new chemical food additive is developed by a cereal manufacturer. Why is it necessary to test for its ability to cause mutation?

We want to prevent any chance that it might cause mutations.

Which of the following DNA mutations is likely to have the most negative effect on the protein it specifies?

a base-pair deletion

What is the direct result of a mutagen?

a change in the sequence of DNA

During RNA processing a(n) _____ is added to the 3' end of the RNA.

a long string of adenine nucleotides

Based on the genetic code chart above, which of the following would be the result of this single base-pair substitution?

a nonsense mutation resulting in early termination of translation

The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the most likely result of this mutation in the protein product?

a polypeptide missing an amino acid

In this activity, you will examine three different mutations.Drag the white and purple labels to the white targets to indicate what each mutant mRNA codon codes for. (You will probably need to consult the codon table for mRNA .)Drag the pink labels to the pink targets to indicate the type of mutation.Drag the blue labels to the blue targets to indicate the effect on the polypeptide's primary structure.Labels may be used once, more than once, or not at all.

a) Val b) Substitution c) missense d) Glu e) Substitution f) Silent g) Stop h) Substitution i) nonsense

In this activity, you will examine two specific nucleotide-pair deletion mutations that affect this region of the CFTR sequence: [delta]F508 and 1660delG.Drag the amino acids to the white targets to indicate what each mRNA codon codes for. (You will probably need to consult the codon table for mRNA.)Drag the blue labels to the blue targets to indicate the effect on the polypeptide's primary structure. Be sure to compare the mutant amino acid sequence to the wild-type sequence above.Labels may be used once, more than once, or not at all.

a)Ile b)Gly c)Val d)Ser e)Phe f)pro g) No frameshift h) frameshift--extensive missense

Label the four mutated DNA segments shown below according to the type of point mutation each represents. Use the codon table above to determine how each mutation would affect the amino acid coding for each segment. Drag the labels to their appropriate locations to identify the type of point mutation shown.

a-silent mutation b-nonsense c-missense d-frameshift

The structure of all 20 amino acids are shown here. At each location of a patient mutation, the wild-type codon codes for the amino acid phenylalanine (Phe). From this figure, you can see that Phe has a nonpolar side chain and is hydrophobic. Compare the structure of Phe to the incorrect amino acid in each patient's insulin. Select the most appropriate conclusion about the impact of each mutation on the shape of the insulin protein.

all of the above -In Patient 1, the mutant codon codes for cysteine (Cys), which has a weakly polar side chain, so it could change the shape of the insulin protein.In Patient 2, the mutant codon codes for serine (Ser), which is polar and hydrophilic, so it is likely to change the shape of the insulin protein.In Patient 3, the mutant codon codes for leucine (Leu), which is nonpolar and hydrophobic, so it might not have much effect on protein shape.

A ribozyme is _

an RNA molecule that functions as an enzyme

Examine the simple metabolic pathway above. A mutation results in a defective enzyme 1. Which of the following results would be a consequence of that mutation?

an accumulation of A and no production of B and C

Accuracy in the translation of mRNA into the sequence of amino acids in a polypeptide depends on specificity in which of the following characteristics?

bonding of the anticodon to the codon and the attachment of amino acids to tRNAs

is a specific molecule, fluorescent protein, or portion of a fluorescent protein that absorbs light at a specific wavelength and causes it to emit light.

chromophore

A series of studies on mutants of Neurospora identified three classes of mutants that needed arginine added to minimal media in order to grow. The production of arginine includes the following steps: precursor → ornithine → citrulline → arginine. What nutrient(s) have to be supplied to the mutants that had a defective enzyme for the ornithine → citrulline step in order to grow?

citrulline

If a DNA sequence is altered from TAGCTGA to TAGTGA, what kind of mutation has occurred?

deletion

Transcription involves the transfer of information from

dna to rna

If a segment of DNA were replicated without any errors, the replicated strand would have the following sequence of nucleotides: 5' - ACTACGTGA - 3' Sort the following replicated DNA sequences by the type of point mutation each contains (frameshift, base substitution, or neither), as compared to the correct sequence shown above. Sort the items into the appropriate bins.

frameshift mutation5'-ACTCGTGA-3'5'-ACTTACGTGA-3'base substitution mutation5'-ACTACGTGT-3'5'-ACTAAGTGA-3'neitherNothing

involves DNA directing the synthesis of proteins or in some cases, just RNA molecules.

gene expression

Which positions in the logo have the least predictable bases? How can you tell?

he 12 positions showing no bases have the lowest predictive power (-18, -17, -16, -12, -11, -6, -5, -4, -2, 5, 6, and 8).

What type of bonding is responsible for maintaining the shape of the tRNA molecule in the figure above?

hydrogen bonding between base pairs

The "universal" genetic code is now known to have exceptions. Evidence for this can be found if which of the following statements is true?

if UGA, usually a stop codon, is found to code for an amino acid such as tryptophan (usually coded for by UGG only)

Suppose that exposure to a chemical mutagen results in a change in the sequence that alters the 5' end of intron 1 (I1). Which of the following results might occur?

inclusion of I1 in the mRNA

What is the name of the process shown in the diagram?

initiation (of translation)

After an RNA molecule is transcribed from a eukaryotic gene, what is removed and what is spliced together to produce an mRNA molecule with a continuous coding sequence?

introns ... exons

primary transcript

is a precursor to RNARNA before being processed; some intron RNARNA acts as a ribozyme, catalyzing its own splicing.

A signal peptide ___

is the first 20 or so amino acids of a protein destined for a membrane location or for secretion from the cell

RNA processing converts the RNA transcript into _____.

mRNA

Which nucleic acid is translated to make a protein?

mRNA

Examine the table of codons in the figure above. What amino acid sequence will be produced based on the following mRNA codon sequence?5'-AUG-UCU-UCG-UUA-UCC-UUG-3'

met-ser-ser-leu-ser-leu

Examine the simple metabolic pathway above. If A, B, and C are all substances required for growth of the organism that carries out this pathway, a strain that is mutant for the gene encoding enzyme 1 would be able to grow on which of the following media?

minimal medium supplemented with nutrient B only

A _________ mutation causes a wild-type amino acid to be replaced by a different amino acid.

missense

During RNA processing a(n) _____ is added to the 5' end of the RNA.

modified guanine nucleotide

RNA polymerase

moves along the template strand of DNA, elongating an RNA molecule in a 5′ → 3′ direction

A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine binds to the growing polypeptide on the other tRNA (#2) already in the ribosome. Which component of the complex described enters the exit tunnel through the large subunit of the ribosome?

newly formed polypeptide

There are how many types of bacterial RNA polymerase?

one

Ribosomal RNA (rRNA)

plays a structural role; as a ribozyme, plays a catalytic role (catalyzes peptide bond formation).

Small RNA

plays structural and catalytic roles in spliceosomes, the complexes of protein and RNARNA that splice pre-mRNAmRNA.

Which three positions in the sequence logo in Figure 3 have the most predictable bases? Name the most frequent base at each position.

position 0 (A); position 1 (T); position 2 (G)

Which two positions in the logo sequence have the most predictable bases, and which bases would you predict at those two positions in a newly sequenced gene?

position 1 (T) and position 2 (G)

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5'-CCG-ACG-3' (mRNA). The charged transfer RNA molecules shown in the figure below (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form. The dipeptide that will form will be

proline-threonine.

Which of the following terms associated with transcription describe regions of nucleic acid?

promoter, gene, terminator

The process of translation in both prokaryotes and eukaryotes requires tRNAs, amino acids, and ribosomal subunits. Which of the following components must also be present for translation to proceed?

protein factors and GTP

In eukaryotic cells, transcription CANNOT begin until _____

several transcription factors have bound to the promoter

A ___________ mutation does not change the wild-type amino acid sequence.

silent

Which of the following is not involved in the formation of a eukaryotic transcription initiation complex?

small RNA molecules

Spliceosomes are composed of _____

small RNAs and proteins

Sort each description by the type of RNA it describes. Drag each item to the appropriate bin.

tRNA: contains an anticodon, has amino acids covalently attached to itmRNA: contains exons, specifies the amino acid sequence for a proteinrRNA: is a component of ribosomes, is the most abundant form of RNA

Which one of the following is true of tRNAs?

tRNAs carry amino acids to the ribosome during translation.

During transcription in eukaryotes, a type of RNA polymerase called RNA polymerase II moves along the template strand of the DNA in the 3'→5' direction. However, for any given gene, either strand of the double-stranded DNA may function as the template strand. For any given gene, what ultimately determines which DNA strand serves as the template strand? View Available Hint(s)

the base sequence of the gene's promoter

In the diagram below, the green unit represents _____.

the promoter

Which of the following events in translation is the first to occur in eukaryotes?

the small subunit of the ribosome recognizing and attaching to the 5' cap of mRNA

What gene feature is represented by the bases in positions 0-2?

the translation start codon AUG

A codon consists of __________ bases and specifies which __________ will be inserted into the polypeptide chain. View Available Hint(s)

three___amino acid

RNA is synthesized from information in the DNA in the process of transcription. For a protein-building gene, the resulting RNA is a transcript (mRNA) of the gene's protein-building instructions.

transcription

What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA?

transcription

RNA plays important roles in many cellular processes, particularly those associated with protein synthesis: transcription, RNA processing, and translation. Drag the labels to the appropriate bins to identify the step in protein synthesis where each type of RNA first plays a role. If an RNA does not play a role in protein synthesis, drag it to the "not used in protein synthesis" bin.

transcription/RNA processing:a) snRNAc) mRNAe) pre-mRNA2. translationb) tRNAf) rRNA3. not used in protein synthesisd) RNA primers

alters the genes of a cell by inducing it to take up and incorporate foreign DNA from the environment.

transformation

The process, performed by the ribosome, of reading mRNA and synthesizing a protein is called

translation

What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?

translation

synthesizes a polypeptide using the information in the mRNA. The cell translates the mRNA nucleotide sequence into the amino acid sequence of the polypeptide.

translation

In eukaryotic cells, the processes of protein synthesis occur in different cellular locations. Drag the labels to the appropriate targets to identify where in the cell each process associated with protein synthesis takes place.

yaass

The following eukaryotic structural gene contains two introns and three exons. The table below shows four possible mRNA products of this gene. Use the labels to explain what mutation(s) may have resulted in each mRNA. Drag the correct label to each location in the table. Labels may be used once, more than once, or not at all.

yass

Which of the following is true of transcription factors?

-Transcription factors bind to promoters. -Transcription factors are produced in a cell as a result of both gene transcription and translation. -Transcription factors are present in eukaryotic cell nuclei. -Transcription factors are proteins.

A nucleotide deletion early in the coding sequence of a gene would most likely result in

-a frameshift mutation -a nonfunctional protein -multiple missense mutations -a nonsense mutation

Complete the following vocabulary exercise related to the process of translation of mRNA to protein by the ribosome. Match the words in the left-hand column with the appropriate blank in the sentences in the right-hand column. View Available Hint(s)

...

Place the events in the transcription of a gene in their proper order from left (first event) to right (last event). Rank from first event to last event.

1. RNA polymerase binds promoter. 2. RNA polymerase transcribes gene. 3.RNA polymerase reaches terminator. 4. RNA polymerase exits gene, RNA is released.

In the diagram below, the two blue strands represent ____

DNA

DNA does not store the information to synthesize which of the following?

Organelles

Use the codon table to determine which mRNA triplets code for the amino acid cysteine, Cys.

There are only two mRNA triplets that code for the amino acid Cys: UGU and UGC.

What is a ribozyme?

a biological catalyst made of RNA

Amino acids are attached to tRNA by enzymes called

aminoacyl-tRNA synthetase

Which component is NOT directly involved in translation?

DNA

Which of the following mutations would likely be most dangerous to a cell?

Deletion of one nucleotide

Drag the mutation types to fill in the table. Labels may be used once, more than once, or not at all.

Missense for all three

Which mutation(s) would not change the remainder of the reading frame of a gene sequence that follows the mutation(s)?

One addition and one deletion mutation.

For each protein, identify its targeting pathway: the sequence of cellular locations in which the protein is found from when translation is complete until it reaches its final (functional) destination. (Note that if an organelle is listed in a pathway, the location implied is inside the organelle, not in the membrane that surrounds the organelle.)

PFK---Cytoplasm onlyinsulin---ER-->Golgi-->outside cell

Which of the following is a stop codon?

UGA

What enzyme catalyzes the attachment of an amino acid to tRNA?

aminoacyl-tRNA synthetase

Which of the following is not transcribed from DNA?

promoter

Part F - Does patient 1 produce functional insulin or not?It is not possible to predict, based on domain information alone, the change in protein function for the SNP in patient 1. More information is needed to assess the function of patient 1's insulin.Insulin regulates blood sugar levels by binding to specific receptor proteins. The ability of insulin to bind its receptor is therefore a critical part of its function. One method that biochemists use to measure the affinity of molecules like insulin to receptors is a competition assay. Radiolabeled wild-type insulin is first bound to a population of insulin receptors. Then various concentrations of unlabeled insulin, either wild-type or mutated forms, are added. How effectively the unlabeled insulin can displace the labeled wild-type insulin is a direct measure of the affinity of the test insulin for the receptor.The graph below shows how effectively three different types of insulin can displace wild-type insulin from its receptor.

1.) lower2..) diabetic

In the sequence alignment (Figure 1), count the number of each base at position 1. Order them from most frequent to least frequent.

10 T, 0 A, 0 C, 0 G

Which of the following statements about mutations is false?

A knock-out mutation results in a total absence of the mutated protein.

Which of the following molecules is/are produced by translation? Include molecules that are subject to further modification after initial synthesis.

Aminoacyl-tRNA synthetase -RNA polymerase

If a mutated DNA sequence produces a protein that differs in one central amino acid from the normal protein, which of the following kinds of mutations could have occurred?

An addition mutation and a deletion mutation.

A part of the promoter, called the TATA box, is said to be highly conserved in many different organisms through evolution. Which of the following correctly describes why this is the case?

Any mutation in the sequence is selected against.

Asking questions and determining the cause for phenomena are at the heart of what many scientists do. In this study, which question below best represents the scientific question asked by the researchers?

Are additional substrates, enzymes, or cofactors from the jellyfish A. victoria required for GFP expression in other species? Submit

Part C - How does each SNP affect the amino acid sequence of the insulin protein?Now that you have identified the location and nucleotide change associated with each SNP, you must next determine how these changes in the gene sequence alter the amino acid sequence of the insulin precursor protein. The wild-type nucleotide sequence of the insulin cDNA is shown below (top line). Below each triplet of nucleotides is the amino acid specified by that codon. (Nucleotide numbers are blue, and amino acid numbers are red.)

Patient 1: T125G- Val- Gly- missensePatient 2: G220A- Ala- Thr- missensePatient 3: G164C- Arg- Pro- missensePatient 4: C309G- Tyr- stop- nonsense

Generally speaking, which of the following mutations would most severely affect the protein coded for by a gene?

a frameshift deletion at the beginning of the gene

The anticodon of a particular tRNA molecule is

complementary to the corresponding mRNA codon

emits light at a specific wavelength after absorbing light at a different wavelength.

fluorescent protein

of translation always happens at the start codon of the mRNA.

initiation

Which binding site on a ribosome holds a tRNA attached to a growing polypeptide chain?

p site