Cell

NUCLEUS

In this slide, notice how we only have one organelle, the nucleus, within the cell. Protein synthesis starts in the nucleus of the cell.

Chromosomes

CellChromosomes

DNA Strands

This slide shows the location of the DNA strands. They are located on the chromosomes.

Chromosomes

RNA Polymerase

In this slide, RNA polymerase unwinds the DNA and creates the mRNA copy. The mRNA copy is made until the RNA polymerase reaches the termination sequence.

DNA Double Helix

mRNA Strand

Promoter Region Start CodonTermination SequenceCoding Region

G G A U C G C A A A U G A C G A C A U U A A G C G A U U A A

C C T A G C G T T T A C T G C T G T A A T T C G C T A A T T

This slide shows the DNA strand unwound while the RNA polymerase has completed the mRNA copy of the DNA strand. When this happens, the RNA polymerase and the mRNA strand fall off of the DNA strand and leave through the nuclear pore. (shown next slide)

The final step of transcription is the mRNA strand goes through a nuclear pore to the cytoplasm. This is the start of the last step in Protein Synthesis, translation.

mRNA Strand

DNA Strand

Nucleus

Cytoplasm

mRNA Strand

Ribosome

G G A U C G C A A A U G A C G A C A U U A A G C G A U U A A

Ribosome

Codon

G G A U C G C A A A U G A C G A C A U U A A G C G A U U A A

The Ribosome begins to read the mRNA sequence.

G G A U C G C A A A U G A C G A C A U U A A G C G A U U A A

Start Codon

tRNA

Anticodon

Amino Acid (Methionine)

U A C

G G A U C G C A A A U G A C G A C A U U A A G C G A U U A A

U A C

The anticodon bonds with the start codon when the ribosome reads it.

Methionine

G G A U C G C A A A U G A C G A C A U U A A G C G A U U A A

U A C U G C

The Ribosome reads the next codon and another tRNA with a complementary anticodon binds. Then, the Ribosome promotes a chemical reaction to join the two amino acids together called a peptide bond.

Peptide bond

ThreonineMethionine

G G A U C G C A A A U G A C G A C A U U A A G C G A U U A A

U G C

As the Ribosome continues down the mRNA strand, the first tRNA falls off, leaving the amino acid.

Methionine

Threonine

G G A U C G C A A A U G A C G A C A U U A A G C G A U U A A

U G C U G U

New tRNA continues to come in and bind to the Ribosome and the amino acids bond.

MethionineThreonine Threonine

A A U

G G A U C G C A A A U G A C G A C A U U A A G C G A U U A A

This continues until the Ribosome reads the Stop Codon.

Stop Codon

Leucine

Threonine

Threonine

Methionine

U C G

G G A U C G C A A A U G A C G A C A U U A A G C G A U U A A

Serine

Leucine

ThreonineThreonineMethionine

A U G A C G A C A U U A A G C G A U G A A G G A U C G U A A

Serine

Leucine

Threonine

ThreonineMethionine

Aspartic Acid

A U U

Glutamic Acid

Glycine Serine

Stop

The ribosome reached the stop codon and has now stopped making amino acids.

A U G A C G A C A U U A A G C G A U G A A G G A U C G U A A

Serine

Leucine

Threonine

ThreonineMethionine

Aspartic Acid

Glutamic Acid

Glycine Serine

Stop

The ribosome falls off of the mRNA strand and the tRNA falls off the ribosome.

The amino acid chain groups together closely to create a three-dimensional structure by the order of which the amino acids where made. This is now a protein.

Summary:

In the nucleus of the cell, RNA polymerase unwinds the DNA double helix structure and creates the mRNA copy for transcription. The starting codon is where the RNA polymerase knows where to start the mRNA strand. The termination sequence is the codon that signals the RNA polymerase to stop copying the DNA strand. The mRNA strand then leaves the nucleus into the cytoplasm where translation starts. In the cytoplasm of the cell, where a ribosome reads the mRNA strand and creates the amino acid chain complementary to the strand. The amino acid chain folds up into a three-dimensional structure called a protein.

CREATED BY JONATHON KOPER AND JACOB GOTWALD.