Transcription and Translation

ABSTACT

In this assignment we were given a chart to fill in. We were asked to go from the DNA to the RNA and calculate the amino acids. We were asked to explain some problems that were given to us and to calculate the chance of a family having a normal child. We were then asked to write a brief essay about mitosis and meiosis and how they are related to and sexual reproduction can create offspring that is different.

Part I

Original DNA Strand:

3'-T A C C C T T T A G T A G C C A C T-5'

Tyr, Pro, Lev, Val, Ala, Thr(Clark, 2011)

Transcription (base sequence of RNA):

AUGGGAAAUCAUCGGUGA-5

Translation (amino acid sequence):

AUG GGA AAU CAU CGG UGA

Methineonine, Glycine, Asparagine, Histidine, Arginine, Stop

Mutated gene sequence one:

3'-T A C G C T T T A G T A G C C A T T-5'

Tyr, Ala, Leu, Val, Ala, Lle (Clark, 2011) Transcription (base sequence of RNA):

AUGCGAAAUCAUCGGUAA

Translation (amino acid sequence):

AUG CGA AAU CAU CGG UAA

Methionine, Arginine, Asparagine, Histidine, Arginine, Stop

Mutated gene sequence two:

3'-T A A C C T T T A C T A G G C A C T-5'

Stop, Pro, Leu, Leu, Gly, Thr (Clark, 2011) Transcription (base sequence of RNA):

AUUGGAAAUGAUCCGUGA

Translation (amino acid sequence):

AUU GGA AAU GAU CCG UGA

Isoleucine, Glycine, Asparagine, Aspartic, Proline, Stop

What is the significance of the first and last codons of an mRNA transcript?

Explanation: The first one starts the protein chain and the last one tells it where to stop. The start point initiates the site for the protein synthesis to start and the end is the transitional stop codon specifies the final amino acid in the encoded protein (The Maize Full Lenght DNA Project).

What meaning do these mRNA codons have for protein synthesis?

Explanation: A sequence of 3 nucleotides (combination of AUGC) will code for a certain amino acid. Amino acids are then polymerized to form proteins (Weegy, 2011).

Did the two mutations result in a change in the final proteins? If so, describe the change.

Response/ explanation: If you are asking about the stopping proteins then yes. They are still both a U, but for sequence 1 the stop codon is UAA which is (Ochre) and in sequence 2 the stop codon is UGA which is (Opal).

In general, why might a change in amino acid sequence affect protein function?

Explanation: Amino acid sequence is what tells the proteins what to do. If the amino acid sequence changes, then the functions of the proteins change and there is not a way for it to complete its original job.

Part II

Punnett Square

a. Chances (%) for healthy child, not a carrier

b. Chances (%) for child that is carrier for cystic fibrosis trait

c. Chances (%) for child with cystic fibrosis

Fill out/adapt Punnett Square:

25% of the offspring will be homozygous dominant (CC).

50% of offspring will be heterozygous(Cc)

25% of offspring will be homozygous