Transcription and Translation Worksheet - Diagrams showing DNA, mRNA, tRNA, and amino acid sequences.

Let’s solve this step by step.

We are given DNA coding strands for two parts: (a) and (b). We need to fill in:

1. DNA template strand — complementary to the coding strand, using base pairing rules:
- A ↔ T
- G ↔ C

2. mRNA — transcribed from the DNA template strand, so it matches the DNA coding strand *except* T becomes U.
- So: DNA template → mRNA: A→U, T→A, G→C, C→G
- Or easier: mRNA is same as DNA coding strand, but with U instead of T.

3. tRNA — carries anticodons that pair with mRNA codons.
- tRNA anticodon is complementary to mRNA codon.
- Base pairing: A↔U, G↔C (in RNA)

4. Amino acid — determined by the mRNA codon (or equivalently, the DNA coding triplet), using the genetic code.

We’ll use standard genetic code table (simplified):

Common codons:

DNA Coding Triplet → mRNA Codon → Amino Acid

ATG → AUG → Methionine (Met)
TTT → UUU → Phenylalanine (Phe)
TTC → UUC → Phe
TTA → UUA → Leucine (Leu)
TTG → UUG → Leu
TCT → UCU → Serine (Ser)
TCC → UCC → Ser
TCA → UCA → Ser
TCG → UCG → Ser
TAT → UAU → Tyrosine (Tyr)
TAC → UAC → Tyr
TGT → UGU → Cysteine (Cys)
TGC → UGC → Cys
TGG → UGG → Tryptophan (Trp)
CTT → CUU → Leu
CTC → CUC → Leu
CTA → CUA → Leu
CTG → CUG → Leu
CCT → CCU → Proline (Pro)
CCC → CCC → Pro
CCA → CCA → Pro
CCG → CCG → Pro
CAT → CAU → Histidine (His)
CAC → CAC → His
CAA → CAA → Glutamine (Gln)
CAG → CAG → Gln
CGT → CGU → Arginine (Arg)
CGC → CGC → Arg
CGA → CGA → Arg
CGG → CGG → Arg
ATT → AUU → Isoleucine (Ile)
ATC → AUC → Ile
ATA → AUA → Ile
ACT → ACU → Threonine (Thr)
ACC → ACC → Thr
ACA → ACA → Thr
ACG → ACG → Thr
AAT → AAU → Asparagine (Asn)
AAC → AAC → Asn
AAA → AAA → Lysine (Lys)
AAG → AAG → Lys
AGT → AGU → Serine (Ser)
AGC → AGC → Ser
AGA → AGA → Arginine (Arg)
AGG → AGG → Arg
GTT → GUU → Valine (Val)
GTC → GUC → Val
GTA → GUA → Val
GTG → GUG → Val
GCT → GCU → Alanine (Ala)
GCC → GCC → Ala
GCA → GCA → Ala
GCG → GCG → Ala
GAT → GAU → Aspartic acid (Asp)
GAC → GAC → Asp
GAA → GAA → Glutamic acid (Glu)
GAG → GAG → Glu
GGT → GGU → Glycine (Gly)
GGC → GGC → Gly
GGA → GGA → Gly
GGG → GGG → Gly

Also stop codons: UAA, UAG, UGA → no amino acid (stop)

Now let’s do part (a):

Given DNA coding strand:
A T G G C T A A C C T T G T A

Step 1: DNA template strand (complementary to coding strand)

Coding: A T G G C T A A C C T T G T A
Template: T A C C G A T T G G A A C A T

(remember: A-T, G-C)

Step 2: mRNA (transcribed from template; or same as coding but T→U)

mRNA: A U G G C U A A C C U U G U A

(Same as coding strand, replace T with U)

Step 3: Break into codons (groups of 3):

mRNA codons:
AUG | GCU | AAC | CUU | GUA

Step 4: tRNA anticodons (complementary to mRNA codons)

tRNA anticodons:
UAC | CGA | UUG | GAA | CAU

(Remember: A-U, G-C in RNA)

Step 5: Amino acids (from mRNA codons)

AUG → Methionine (Met)
GCU → Alanine (Ala)
AAC → Asparagine (Asn)
CUU → Leucine (Leu)
GUA → Valine (Val)

So for part (a):

DNA template: T A C C G A T T G G A A C A T
mRNA: A U G G C U A A C C U U G U A
tRNA: U A C | C G A | U U G | G A A | C A U
amino acid: Met | Ala | Asn | Leu | Val

Now part (b):

DNA coding strand:
C A G G A T G A A T T G C T C

Step 1: DNA template strand (complementary)

Coding: C A G G A T G A A T T G C T C
Template: G T C C T A C T T A A C G A G

Step 2: mRNA (same as coding, T→U)

mRNA: C A G G A U G A A U U G C U C

Step 3: Break into codons:

CAG | GAU | GAA | UUG | CUC

Step 4: tRNA anticodons (complementary to mRNA)

GUC | CUA | CUU | AAC | GAG

Step 5: Amino acids

CAG → Glutamine (Gln)
GAU → Aspartic acid (Asp)
GAA → Glutamic acid (Glu)
UUG → Leucine (Leu)
CUC → Leucine (Leu)

So for part (b):

DNA template: G T C C T A C T T A A C G A G
mRNA: C A G G A U G A A U U G C U C
tRNA: G U C | C U A | C U U | A A C | G A G
amino acid: Gln | Asp | Glu | Leu | Leu

Final Answer:

Part (a):

DNA (template): T A C C G A T T G G A A C A T
mRNA: A U G G C U A A C C U U G U A
tRNA: U A C C G A U U G G A A C A U
amino acid: Met Ala Asn Leu Val

Part (b):

DNA (template): G T C C T A C T T A A C G A G
mRNA: C A G G A U G A A U U G C U C
tRNA: G U C C U A C U U A A C G A G
amino acid: Gln Asp Glu Leu Leu