11-17-20 Transcription & Translation Practice.docx - Name Date Per ... - Free Printable

Problem Description:

The task involves analyzing a DNA sequence and determining the corresponding mRNA transcript and protein product through transcription and translation. The provided DNA sequence is:

DNA Sequence:
```
TAC GAG CTC TAT GGT AGC CCG AAG
```

We are tasked with:
1. Transcribing the DNA sequence into mRNA.
2. Translating the mRNA sequence into an amino acid sequence (protein).
3. Identifying any stop codons in the mRNA sequence.

---

Solution:

#### Step 1: Transcription (DNA to mRNA)
Transcription is the process of converting DNA into mRNA. During this process:
- Each base in the DNA strand is replaced by its complementary base in RNA.
- In RNA, uracil (U) replaces thymine (T).

The rules for transcription are:
- `A` (adenine) in DNA → `U` (uracil) in RNA
- `T` (thymine) in DNA → `A` (adenine) in RNA
- `G` (guanine) in DNA → `C` (cytosine) in RNA
- `C` (cytosine) in DNA → `G` (guanine) in RNA

Given the DNA sequence:
```
TAC GAG CTC TAT GGT AGC CCG AAG
```

We replace each base according to the rules:
- `T` → `A`
- `A` → `U`
- `C` → `G`
- `G` → `C`

Performing the substitution:
```
TAC → AUG
GAG → CUC
CTC → GAG
TAT → AAU
GGT → CCC
AGC → UCG
CCG → GGC
AAG → UUC
```

Thus, the transcribed mRNA sequence is:
```
AUG CUC GAG AAU CCC UCG GGC UUC
```

---

#### Step 2: Translation (mRNA to Protein)
Translation is the process of converting the mRNA sequence into an amino acid sequence using the genetic code. The genetic code is read in triplets called codons, and each codon corresponds to a specific amino acid or a stop signal.

Using the standard genetic code:
- `AUG` = Methionine (Start codon)
- `CUC` = Leucine
- `GAG` = Glutamic Acid
- `AAU` = Asparagine
- `CCC` = Proline
- `UCG` = Serine
- `GGC` = Glycine
- `UUC` = Phenylalanine

Reading the mRNA sequence in codons:
```
AUG CUC GAG AAU CCC UCG GGC UUC
```

Translating each codon:
- `AUG` → Methionine (Start)
- `CUC` → Leucine
- `GAG` → Glutamic Acid
- `AAU` → Asparagine
- `CCC` → Proline
- `UCG` → Serine
- `GGC` → Glycine
- `UUC` → Phenylalanine

Thus, the amino acid sequence (protein) is:
```
Methionine - Leucine - Glutamic Acid - Asparagine - Proline - Serine - Glycine - Phenylalanine
```

In one-letter notation:
```
M L E N P S G F
```

---

#### Step 3: Identifying Stop Codons
Stop codons are special codons that signal the end of translation. The three stop codons are:
- `UAA`
- `UAG`
- `UGA`

In the given mRNA sequence:
```
AUG CUC GAG AAU CCC UCG GGC UUC
```

There are no stop codons (`UAA`, `UAG`, or `UGA`) present in the sequence. Therefore, the translation continues until the end of the mRNA.

---

Final Answer:

1. Transcribed mRNA Sequence:
```
AUG CUC GAG AAU CCC UCG GGC UUC
```

2. Translated Protein Sequence:
```
Methionine - Leucine - Glutamic Acid - Asparagine - Proline - Serine - Glycine - Phenylalanine
```
Or in one-letter notation:
```
M L E N P S G F
```

3. Stop Codons:
No stop codons are present in the mRNA sequence.

Boxed Final Answer:
$$
\boxed{\text{AUG CUC GAG AAU CCC UCG GGC UUC; M L E N P S G F; No stop codons}}
$$