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genes, proteins, mutations

transcribe and translate each of these 3 following DNA gene sequences'
1. 3'-TACCCTTTAGTAGCCACT-5 original gene sequence
2. 1 3'-TACGCTTTAGTAGCCATT-5' mutated gene sequence.
3. 2 3'-TAACCTTTACTAGGCACT-5' mutated gene sequence
What is the significance of the first and last codons of an mRNA transcript.
what meaning do these mRNA codons have for protein synthesis?
did the mutations result in a change in the final proteins? If so, describe the change.
In general, why might a change in amino acid sequence affect protein function?
normal allele;c=allele for CYSTIC FIBROSIS. Based on the Punnett Square calculate %'s for having a health child (not a carrier), a child that is a carrier for the Cystic Fibrosis trait, and a child with Cystic Fibrosis

Solution Preview

1. Transcription is the process of copying the message in the DNA into RNA. In order to determine the correct transcribed sequence, it is important to understand the direction of transcription and the selection of bases in the sequence.

Transcription occurs in the 5' to 3' direction using DNA as the template. This directionality also means the template strand is read 3' to 5' for the transcription because DNA stands are antiparallel. For example, in the first sequence in the posted question, the strand is read starting from 3'-TAC and ending with ACT-5'.

Each A in the template DNA strand is paired with a U in the newly synthesized RNA.
In reverse, each T in DNA is paired with an A.

Each G in the template DNA strand is paired with a C in the newly synthesized RNA.
In reverse, each C in DNA is paired with a G.

Let's use the understanding of direction and base pairing to transcribe the first sequence.

DNA template: 3'-TAC CCT TTA GTA GCC ACT-5'
Transcribed RNA: 5'-AUG GGA AAU CAU CGG UGA-3'

2. Translation is the process of making protein using the coded message in the RNA. It is like translating a message in one language to another language because the message in the form of nucleic acids in RNA is changed to amino acids in the protein. This is in contrast to transcription where the message is only transcribed (copied) from one nucleic acid to another (DNA to RNA).

Similar to translating sentences one "word" at a time into another language, RNA to protein translation is done one codon at a time. Each codon consists of 3 ...