Central+Dogma+Pathway

GENE TABLE 1: WILD-TYPE MC1R GENE (LIGHT COAT-COLOR PHENOTYPE) 015 022 DNA TTG AGG TGG GCG TGT CCG CAA GGA mRNA AAC UCC ACC CGC ACA GGC GUU CCU Amino Acid ASN SER THR ARG THR GLY VAL PRO 105 112 DNA CGG GAC CGG TGG GCC CAC TGA CAC mRNA GCC CUG GCC ACC CGG GUG ACU GUG Amino Acid ALA LEU ALA THR ARG VAL THR VAL 154 161 DNA TCA TAA CAC TGT GAC GGG GCC CGA mRNA AGU AUU GUG ACA CUG CCC CGG GCU Amino Acid Ser lie val thr leu pro arg ala 209 212 DNA GTG TAC GAA CGT mRNA CAC AUG CUU GCA Amino Acid his met leu ala 230 237 DNA GAA CAG GTG GTT CCA AAG GCT GAG mRNA CUU GUC CAC CAA GGU UUC CGA CUC Amino Acid leu val his gln gly phe arg leu GENE TABLE 2: MUTANT MC1R GENE ( DARK COAT-COLOR PHENOTYPE) 015 022 DNA TTG AGG TGG ACG TGT CCG CAA GGA mRNA ACC UCC ACC UGC ACA GGC GUU CCU Amino Acid Asn ser thr cys thr gly val pro 105 112 DNA CGG GAC CGG TGG ACC CAC TGA CAC mRNA GCC CUG GCC ACC UGG GUG ACU GUG Amino Acid ala leu ala thr trp val thr val 154 161 DNA TCA TAA CAC TGT GAC GGG ACC CGA mRNA AGU AUU GUG ACA CUG CCC UGG GCU Amino Acid ser lle val thr leu pro trp ala 209 212 DNA GTG TAC GAG CGT mRNA CAC AUG CUC GCA Amino Acid his met leu ala 230 237 DNA GAA CAG GTG GTG CCA AAG GCT GAG mRNA CUU GUC CAC CAC GGU UUC CGA CUC Amino Acid leu val his his gly phe arg leu

QUESTIONS 1. The Mc1r gene codes for the ______________________ protein. Melanocortin 1 receptor 2. If the MC1R protein is 317 amino acids long, why are there 954 base pairs in the coding region of the gene? Each amino acid has 3 bases, itself, mRNA codon and DNA triplet. 317 x 3 = 951 Then plus 3 extra base pairs corresponding a stop codon so +3 = 954 3. Of the five mutations you identified in the mutant Mc1r gene, how many are: ____5____substitutions _0________ insertions 0___________ deletions (Enter a number on each line.) 4. Of the five mutations you identified in the Mc1r gene, how many are: ______1___silent ____4______missense 0__________ nonsense (Enter a number on each line.) 5. Mice with the wild-type (nonmutant) Mc1r gene have light-colored fur. Which pigment is responsible for this coloration? Pheomelanin 6. Using the information in the introduction on mutations and your knowledge of proteins, develop a hypothesis to explain how the changes in the MC1R protein’s amino acid sequence might affect its function. I believe it will change its structure of proteins therefor altering the protein function 7. Explain how silent mutations affect the structure and function of the protein.

Gene Expression Steps Molecules Involved What molecules and proteins are involved in this step? Summary What happens during this step? Transcription DNA, rna, MRNA, rho factor, sigma factor and nucleotides RNA polymerase transcribes a gene’s DNA into RNA transcript. RNA Splicing Noncoding regions called exons, introns, ribozymes RNA transcript is edited through splicing. Splicesome trims out introns and splices exons together to produce mRNA mRNA Transport mRNA, nucleus, cytoplasm .mRNA is transported to the cytoplasm from the nucleus Translation Ribosomes, tRNA, mRNA, amino acids release factors, magnesium proteins and ribosomes RNA’s translate mRNA into amino acids. Which then so only conducting a polypeptide chain

Protein Processing RNA mRNA, tRNA, and ribosomal RNA. then once the polypeptide is finished it is the assembled into a 3d functional protein. Happening in the cytoplasm or in the endoplasmic reticulum and golgi system 12. In gene expression, which enzyme is responsible for transcribing the DNA sequence into mRNA by adding complementary RNA nucleotides? RNA polymerase 13. In a eukaryotic cell, where does transcription occur? The nucleus 14. Describe the process of translation. Info is encoded in mRNA which adds of amino acids during protein synthesis 15. In a eukaryotic cell, which main organelle is involved in translation? Ribosome 16. Explain the relationship between DNA sequence, amino acid sequence, and protein structure and function. DNA provides the code, Amino acid determines the structure of protein