Module 5: Recitation 9 Gene Expression

5' - AUG - GAC - CUC - UCU - GCA - CUA - CGU - GUG - GAA - GAG - GUA - CAA - AAC - 3' The mRNA sequence should be the same as the coding sequence except thymine is replaced with uracil.

Consider the DNA coding strand 5' - ATG - GAC - CTC - TCT - GCA - CTA - CGT - GTG - GAA - GAG - GTA - CAA - AAC - 3' What is the corresponding mRNA sequence? 3' - UAC - CUG - GAG - AGA - CGU - GAU - GCA - CAC - CUU - CUC - CAU - GUU - UUG - 5' 3' - TAC - CTG - GAG - AGA - CGT - GAT - GCA - CAC - CTT - CTC - CAT - GTT - TTG - 5' 5' - ATG - GAC - CTC - TCT - GCA - CTA - CGT - GTG - GAA - GAG - GTA - CAA - AAC - 3' 5' - AUG - GAC - CUC - UCU - GCA - CUA - CGU - GUG - GAA - GAG - GUA - CAA - AAC - 3'

Thr - Thr - Ser From this DNA-template strand we can determine the DNA coding strand, which would be: 5' ACGACCTCG 3'. From the DNA coding strand we can then determine the mRNA sequence, which would be: 5' ACGACCUCG 3'. From the mRNA sequence the amino acid sequence can now be determined. The 3-letter codons would be: ACG - ACC - UCG, and therefore the amino acids would be: Thr - Thr - Ser.

Consider the DNA-template strand: 3' TGCTGGAGC 5'. What is the correct amino acid sequence? Pro - Cys - Gly Thr - Thr - Ser Arg - Thr - Pro Tyr - Arg - His

MDLSALRVEEVQN To obtain the correct answer you must first determine the correct mRNA sequence. The mRNA and tRNA sequences are complementary, just like how the DNA coding and template strand are complementary. Once the mRNA sequence is obtained, then the amino acid sequence can be determined by following an amino acid table/wheel that shows the one letter abbreviations. MRN: 5' - AUG - GAC - CUC - UCU - GCA - CUA - CGU - GUG - GAA - GAG - GUA - CAA - AAC - 3'

Consider the tRNA sequence 3' - UAC - CUG - GAG - AGA - CGU - GAU - GCA - CAC - CUU - CUC - CAU - GUU - UUG - 5' What is the corresponding amino acid sequence using the one-letter amino acid abbreviations? Hint: Refer to the amino acid table below that shows the one-letter amino acid abbreviations. MDLSALRVEEVQN YLGAADAHLLHVC MDLSALRVGGVGA YLERRDAHLLHVC

Answer 1: 3' Answer 2: 5' Answer 3: 3' Answer 4: 3' Answer 5: N-terminus The DNA coding strand is 5' to 3' with a corresponding DNA template strand that is 3' to 5'. This template strand has a corresponding mRNA strand that is 5' to 3'. This mRNA strand has a corresponding tRNA strand that is 3' to 5'. The final amino acid sequence is then N-terminus to C-terminus. Cancel

Fill in the correct end type for each molecule listed, using the already provided ends as guidance. Assume these molecules are lined up as depicted. End Molecule type End 5' DNA coding strand _____ 3' DNA template strand ——- 5' mRNA ______ _____ tRNA 5' _____ Amino acid sequence C-terminus

RNA; 5'-ACCUGUAGCG-3' The correct mRNA sequence should be the same as the DNA coding sequence except thymine is replaced with uracil. The direction should also be the same.

Given the following DNA coding sequence: 5'-ACCTGTAGCG-3'. Which of the answers below represents the mRNA sequence in the correct direction for this sequence? RNA; 5'-ACCUGUAGCG-3' DNA; 5'-GUCTTAUCGT-3' RNA; 5'-AGGUCGGTCC-3' DNA; 3'-UGGACAUCGC-5'

Leucine would be substituted with Proline This mutation would result in a Proline amino acid instead of the original Leucine corresponding the DNA triplet.

If the coding DNA triplet CTA for Leucine in the middle of the gene sequence mutates to CCA what would you expect during translation? Translation would stop prematurely Translation won't be initiated This codon will be skipped Leucine would be substituted with Proline

A substance that prevents the transfer of amino acids to the growing polypeptide chain A substance that prevents the transfer of amino acids to the growing polypeptide chain would block mature mRNA from being translated into protein. All other options listed would prevent translation by impeding at an earlier stage of the Central Dogma.

Recall the Central Dogma (DNA-mRNA-Protein). Which of the following would block mature mRNA from being translated into protein? A substance that prevents the mRNA processing A substance that prevents the transfer of amino acids to the growing polypeptide chain A substance that blocks the active site of RNA polymerase A substance that causes a mutation in DNA template

False The codon AUG has multiple purposes. This codon initiates the start of protein synthesis and codes for the first amino acid in protein synthesis, which is methionine.

The codon AUG only has one purpose which is to indicate the start of protein synthesis? True False

Initiation, elongation, termination Initiation, elongation, termination are the correct order of transcription and translation steps.

The correct order of transcription and translation steps Initiation, elongation, termination None of the answers is correct. Indication, extension, completion Hot start, amplification, ligation

False Translation in prokaryotes can occur simultaneously to transcription due to the lack of nucleus.

Translation in prokaryotes can occur without transcription due to the lack of nucleus. True False

truncated BRCA1

Using the amino acid sequence from question 11, complete the following steps to process the sequence and then answer the question below. Go to http://www.ncbi.nlm.nih.gov/BLAST/ Links to an external site. and choose Protein BLAST under the Basic BLAST heading. Enter the one-letter abbreviations for the amino acid sequence in the SEARCH box labeled "Enter Query Sequence". Be sure to enter them in the correct order without any spaces, commas, or anything else. Scroll down to the bottom of the page and click on the "BLAST" button. Wait - It may take a few minutes to process your sequence. (BLAST is running an algorithm which aligns your input sequence with known sequences stored in databases. It will return a table of database sequences which represent the best matches.) Once your sequence is processed, scroll down to the list of proteins that matched your sequence. They are sorted with the best matches at the top. What is the best match for the protein this sequence encodes for? ATP-binding cassette domain-containing protein ASCH domain-containing protein truncated BRCA1 fatty acyl-AMP ligase

Breast Cancer Type 1 This protein is involved with BReast CAncer Type 1 (hence the protein name BRCA1).

Using the protein name from question 12, complete the following steps and then answer the question below. Go to www.google.com Links to an external site. Enter the protein name is the search bar and hit enter. Look through the results to determine what disease this protein is involved with. What disease is this protein involved with? Breast Cancer Type 1 Mycobacterium tuberculosis This protein is NOT known to be involved with a disease. Breast Cancer Type 2

UGA Stop codons include: UAG, UAA, and UGA

Which of the following 3 letter codon sequence serves as a stop codon? UAC UGG UAU UGA