Question

name
date:
block:
mrna codon practice
level 2
instructions: use the mrna codon chart on the left to find
the amino acid for the following dna codes.

1. find the amino acid for the dna code atg:

1. find the amino acid for the dna code aag:

3 find the amino acid for the dna code acc.

1. find the amino acid for the dna code ata:

1. find the amino acid for the dna code ccg

instructions: use the mrna codon chart above to find the amino acid for the following
dna codes.

1. find the amino acid for the dna code ttt:

1. find the amino acid for the dna code aaa.

1. find the amino acid for the dna code ccc:

1. find the amino acid for the dna code att

1. find the amino acid for the dna code tcg

Explanation:

Step1: Recall DNA to mRNA Transcription

DNA bases: A, T, C, G. mRNA bases: A, U, C, G (T→U). So for a DNA code, replace T with U to get mRNA codon.

Step2: Use Codon Chart for Amino Acid

After getting mRNA codon, use the codon chart (either circular or table) to find the corresponding amino acid.

1. DNA code ATG

- Transcribe to mRNA: Replace T with U → AUG.
- From codon chart, AUG codes for Methionine (or Start, but as amino acid, Methionine).

2. DNA code AAG

- Transcribe to mRNA: AAG → AAG (wait, T→U: DNA AAG → mRNA AAG? Wait, DNA base T pairs with A, so DNA A (adenine) pairs with U (uracil) in mRNA? Wait no: DNA to mRNA is transcription, where DNA template strand is used. Wait, the DNA code here is the coding strand? Wait, typically, DNA coding strand (same as mRNA except T→U). So DNA ATG (coding strand) → mRNA AUG. So for DNA code (coding strand) AAG: T is replaced by U, so mRNA codon is AAG? Wait no, DNA base T (thymine) is transcribed to U (uracil) in mRNA. So DNA A (Adenine) → mRNA A (Adenine), DNA T (Thymine) → mRNA U (Uracil), DNA C (Cytosine) → mRNA C (Cytosine), DNA G (Guanine) → mRNA G (Guanine). So DNA code (coding strand) ATG: A (DNA) → A (mRNA), T (DNA) → U (mRNA), G (DNA) → G (mRNA) → mRNA AUG. Correct. So DNA AAG: A→A, A→A, G→G? Wait no, T is the one replaced. Wait, DNA has A, T, C, G. So in DNA, the bases are A (adenine), T (thymine), C (cytosine), G (guanine). In mRNA, it's A (adenine), U (uracil), C (cytosine), G (guanine). So when transcribing DNA (coding strand) to mRNA, T is replaced with U. So DNA code: ATG (A, T, G) → mRNA: A, U, G (AUG). DNA code AAG (A, A, G) → mRNA: A, A, G (AAG)? Wait, no, T is only in DNA, so if DNA has T, replace with U. If DNA has A, it stays A in mRNA? Wait, no: the base pairing in transcription is DNA template strand (A-T, C-G) paired with mRNA (U-A, G-C). So the coding strand (non-template) of DNA has the same sequence as mRNA except T→U. So yes, coding strand DNA ATG → mRNA AUG. So for DNA code (coding strand) AAG: A (coding) → A (mRNA), A (coding) → A (mRNA), G (coding) → G (mRNA)? Wait, no, T is the base that is replaced. So if DNA has T, mRNA has U. If DNA has A, mRNA has A? Wait, no, the template strand (non-coding) of DNA is what's transcribed. The template strand has A-T, C-G pairing with mRNA. So template strand DNA: TAC (for coding strand ATG) → mRNA AUG. Wait, maybe I confused coding and template. Let's clarify: To get mRNA from DNA, the DNA template strand is used, where A (DNA) pairs with U (mRNA), T (DNA) pairs with A (mRNA), C (DNA) pairs with G (mRNA), G (DNA) pairs with C (mRNA). So template strand DNA: TAC (for coding strand ATG) → mRNA AUG. So if the given DNA code is the coding strand (like in the problem, "DNA code" probably means coding strand), then we replace T with U to get mRNA. So DNA coding strand ATG: T→U → mRNA AUG. DNA coding strand AAG: T is not present, so mRNA AAG? Wait, no, AAG in DNA coding strand: A (coding) → A (mRNA), A (coding) → A (mRNA), G (coding) → G (mRNA)? No, that can't be. Wait, no, the coding strand has the same sequence as mRNA except T→U. So yes, coding strand DNA: A (Adenine) → mRNA A (Adenine), T (Thymine) → mRNA U (Uracil), C (Cytosine) → mRNA C (Cytosine), G (Guanine) → mRNA G (Guanine). So DNA coding strand: ATG → mRNA AUG (correct, as AUG is start codon, Methionine). DNA coding strand AAG: A→A, A→A, G→G? Wait, no, T is the only base in DNA that is replaced with U. So if DNA has T, replace with U; others stay same. So DNA AAG (no T) → mRNA AAG. Then from codon chart, AAG: first letter A, second A, third G. Looking at the table: first letter A, second letter A, third letter G: Lysine. Wait, the table: first letter A, second A, third G: Lysine? Let's check the table. The table has first letter A, second letter A: rows where first is A, second is A. Third letter G: in the A (first), A (second) column, third letter G: Lysine? Wait the table: first letter A, second letter A: the rows are Isoleucine, Isoleucine, Isoleucine, Methionine (START), then Valine? Wait no, the table: first letter (leftmost) A: then second letter (top) U, C, A, G. Wait the table's first letter column: U, C, A, G. Wait no, the table's first letter is on the left (U, C, A, G), second letter top (U, C, A, G), third letter right (U, C, A, G). Wait the user's table: first letter (left) U, C, A, G; second letter (top) U, C, A, G; third letter (right) U, C, A, G. So for mRNA codon AAG: first letter A, second letter A, third letter G. So first letter A (left column: A), second letter A (top row: A), third letter G (right column: G). So the cell at first A, second A, third G: looking at the table, under first letter A, second letter A: the rows are Isoleucine (U), Isoleucine (C), Isoleucine (A), Methionine (G), then Valine? Wait no, the table: first letter A, second letter U: Isoleucine (U), Isoleucine (C), Isoleucine (A), Methionine (G). Then first letter A, second letter A: the rows? Wait the user's table:

First letter (left): U, C, A, G

Second letter (top): U, C, A, G

Third letter (right): U, C, A, G

Looking at the table:

First letter U:

- Second U: Phenylalanine (U), Phenylalanine (C), Leucine (A), Leucine (G)

- Second C: Serine (U), Serine (C), Serine (A), Serine (G)

- Second A: Tyrosine (U), Tyrosine (C), (STOP) (A), (STOP) (G)

- Second G: Cysteine (U), Cysteine (C), Tryptophan (A), Tryptophan (G)

First letter C:

- Second U: Leucine (U), Leucine (C), Leucine (A), Leucine (G)

- Second C: Proline (U), Proline (C), Proline (A), Proline (G)

- Second A: Histidine (U), Histidine (C), Glutamine (A), Glutamine (G)

- Second G: Arginine (U), Arginine (C), Arginine (A), Arginine (G)

First letter A:

- Second U: Isoleucine (U), Isoleucine (C), Isoleucine (A), Methionine (G)

- Second C: Threonine (U), Threonine (C), Threonine (A), Threonine (G)

- Second A: Asparagine (U), Asparagine (C), Lysine (A), Lysine (G)

- Second G: Serine (U), Serine (C), Arginine (A), Arginine (G)

First letter G:

- Second U: Valine (U), Valine (C), Valine (A), Valine (G)

- Second C: Alanine (U), Alanine (C), Alanine (A), Alanine (G)

- Second A: Aspartate (U), Aspartate (C), Glutamate (A), Glutamate (G)

- Second G: Glycine (U), Glycine (C), Glycine (A), Glycine (G)

Ah, there we go. So first letter A, second letter A, third letter G: Lysine (since in first A, second A, third G: Lysine). So DNA code AAG → mRNA AAG → Lysine.

3. DNA code ACC

- Transcribe to mRNA: A (DNA)→A (mRNA), C (DNA)→C (mRNA), C (DNA)→C (mRNA)? Wait no, DNA code ACC: T is not present, so replace T with U? Wait DNA ACC: A, C, C. So mRNA: A, C, C (since no T). Wait DNA ACC: A (DNA)→A (mRNA), C (DNA)→C (mRNA), C (DNA)→C (mRNA)? No, T is only replaced. So DNA ACC → mRNA ACC? Wait no, DNA has T, so if DNA has T, replace with U. If DNA has A, C, G, they stay A, C, G in mRNA? Wait no, the transcription is DNA template strand (A-T, C-G) to mRNA (U-A, G-C). So coding strand (same as mRNA except T→U). So DNA coding strand ACC: A→A, C→C, C→C? No, T is replaced by U. So DNA coding strand ACC: A (Adenine) → A (mRNA), C (Cytosine) → C (mRNA), C (Cytosine) → C (mRNA). Wait, but T is not in the code, so mRNA codon is ACC. Then from codon chart: first letter A, second letter C, third letter C. First letter A, second letter C: Threonine (U), Threonine (C), Threonine (A), Threonine (G). So third letter C: Threonine (C). So mRNA ACC → Threonine.

4. DNA code ATA (assuming typo, maybe ATA? Or A1A? Probably ATA)

- Transcribe to mRNA: ATA → AUA (replace T with U).
- mRNA codon AUA: first letter A, second letter U, third letter A. First letter A, second letter U: Isoleucine (U), Isoleucine (C), Isoleucine (A), Methionine (G). So third letter A: Isoleucine.

5. DNA code CCG

- Transcribe to mRNA: CCG → CCG (replace T with U, but no T here). Wait DNA CCG: C→C, C→C, G→G? No, T is replaced by U. So DNA CCG → mRNA CCG. Then mRNA codon CCG: first letter C, second letter C, third letter G. First letter C, second letter C: Proline (U), Proline (C), Proline (A), Proline (G). Third letter G: Proline (G). So Proline.

6. DNA code TTT

- Transcribe to mRNA: TTT → UUU (replace T with U).
- mRNA UUU: first letter U, second letter U, third letter U. First letter U, second letter U: Phenylalanine (U). So Phenylalanine.

7. DNA code AAA

- Transcribe to mRNA: AAA → AAA (replace T with U, no T). Wait DNA AAA → mRNA AAA? No, T is replaced by U, but AAA has no T. So mRNA AAA. Then mRNA codon AAA: first letter A, second letter A, third letter A. First letter A, second letter A: Isoleucine (U), Isoleucine (C), Isoleucine (A), Methionine (G). Wait no, first letter A, second letter A, third letter A: in the table, first A, second A, third A: Lysine? Wait no, first A, second A: the rows are Isoleucine (U), Isoleucine (C), Isoleucine (A), Methionine (G). Wait no, the table for first A, second A: third letter U: Isoleucine, C: Isoleucine, A: Isoleucine, G: Methionine. Wait no, the table:

First letter A, second letter U:

- Third U: Isoleucine

- Third C: Isoleucine

- Third A: Isoleucine

- Third G: Methionine (START)

First letter A, second letter A:

- Third U: (wait no, second letter A is top row A. So first letter A, second letter A: the column is A (top). So first letter A (left), second letter A (top), third letter A (right): the cell is Isoleucine? No, the table:

Wait the user's table:

First letter (left) U:

- Second U: Phenylalanine (U), Phenylalanine (C), Leucine (A), Leucine (G)

- Second C: Serine (U), Serine (C), Serine (A), Serine (G)

- Second A: Tyrosine (U), Tyrosine (C), (STOP) (A), (STOP) (G)

- Second G: Cysteine (U), Cysteine (C), Tryptophan (A), Tryptophan (G)

First letter C:

- Second U: Leucine (U), Leucine (C), Leucine (A), Leucine (G)

- Second C: Proline (U), Proline (C), Proline (A), Proline (G)

- Second A: Histidine (U), Histidine (C), Glutamine (A), Glutamine (G)

- Second G: Arginine (U), Arginine (C), Arginine (A), Arginine (G)

First letter A:

- Second U: Isoleucine (U), Isoleucine (C), Isoleucine (A), Methionine (G)

- Second C: Threonine (U), Threonine (C), Threonine (A), Threonine (G)

- Second A: Asparagine (U), Asparagine (C), Lysine (A), Lysine (G)

- Second G: Serine (U), Serine (C), Arginine (A), Arginine (G)

First letter G:

- Second U: Valine (U), Valine (C), Valine (A), Valine (G)

- Second C: Alanine (U), Alanine (C), Alanine (A), Alanine (G)

- Second A: Aspartate (U), Aspartate (C), Glutamate (A), Glutamate (G)

- Second G: Glycine (U), Glycine (C), Glycine (A), Glycine (G)

Ah! So first letter A, second letter A: the column is A (top). So the row is first letter A, second letter A: the cells are Asparagine (U), Asparagine (C), Lysine (A), Lysine (G). So third letter A: Lysine, third letter G: Lysine. So mRNA AAA: first A, second A, third A: Lysine (since third letter A in first A, second A column: Lysine). So DNA AAA → mRNA AAA → Lysine.

8. DNA code CCC

- Transcribe to mRNA: CCC → CCC (replace T with U, no T). mRNA CCC: first letter C, second letter C, third letter C. First letter C, second letter C: Proline (U), Proline (C), Proline (A), Proline (G). Third letter C: Proline (C). So Proline.

9. DNA code ATT

- Transcribe to mRNA: ATT → AUU (replace T with U). mRNA AUU: first letter A, second letter U, third letter U. First letter A, second letter U: Isoleucine (U). So Isoleucine.

10. DNA code TCG

- Transcribe to mRNA: TCG → UCG (replace T with U). mRNA UCG: first letter U, second letter C, third letter G. First letter U, second letter C: Serine (U), Serine (C), Serine (A), Serine (G). Third letter G: Serine (G). So Serine.

Answers:

1. Methionine
2. Lysine
3. Threonine
4. Isoleucine (assuming ATA, if A1A is typo)
5. Proline
6. Phenylalanine
7. Lysine
8. Proline
9. Isoleucine
10. Serine

(Note: For question 4, "A1A" is likely a typo, assumed ATA. If different, adjust transcription.)

Answer:

s:

1. Methionine
2. Lysine
3. Threonine
4. Isoleucine (assuming ATA, if A1A is typo)
5. Proline
6. Phenylalanine
7. Lysine
8. Proline
9. Isoleucine
10. Serine

(Note: For question 4, "A1A" is likely a typo, assumed ATA. If different, adjust transcription.)