steps of protein synthesis

Steps of Protein Synthesis

1. DNA is transcribed into messenger RNA (mRNA) by an enzyme known as:

RNA polymerase, which builds an RNA strand that is complimentary to the DNA strand.

2. Before translation can happen mRNA must move out of the nucleus and into the cytoplasm.

Messenger RNA - mRNA

DNA’s “recipes” are transcribed by the enzyme ____ ____________ to make a molecule of mRNA.

mRNA is like a different language that the ribosome (protein building machine) can read.

Messenger RNA - mRNA

The message of mRNA is carried in “codons”

A codon is a three base sequence that will code for an Amino Acid (the building block of a proteins.

Together the codons in the mRNA strand code for 1 protein, typically hundreds or thousands of Amino Acids

DNA

DNA + DNA

mRNA

DNA or RNA?

Modeling Transcription

1. Build DNA molecule

2. Build mRNA molecule

LAB CHANGES*Only build 1 strand of DNA*Cut pipe cleaners into 4

pieces

Transcription (the first part of Protein

Synthesis)

A type of RNA, called mRNA (messenger)

goes into the nucleus and copies the DNA

The next step is that mRNA moves from the

nucleus to the cytoplasm.

DNA – ATCG

mRNA - UAGC

Animation Link

Any change in the DNA structure (specifically the order of nitrogen bases) is a mutation.

Mutations can be helpful, harmful, or neutral.

Helpful – can create diversity in a population

Harmful – can cause things like cancerNeutral – can have absolutely no effect at all

A mutagen is something that causes mutations in the DNA (for example: smoking, radiation from the sun etc)

Slooze Worm

An insertion mutation is when a nitrogen base is added to the existing DNA

A deletion mutation is when a nitrogen base is subtracted from the DNA

A substitution mutation is when one nitrogen base is put in place of another.

If our DNA was AATTGGCC

An insertion would be AATTAGGCC

A deletion would be AATGGCC

A substitution would be AAATGGCC

DNA Fingerprinting – technique used in criminal investigations.

DNA Fingerprinting takes the DNA out of a cell and separates it. This will allow investigators to

distinguish body cells of different individuals (since they are unlikely to have the same DNA)

Cloning – take the DNA out of one of

your cells then take the DNA out of a zygote (fertilized egg). Put the DNA from your cell into

the zygote.

Genetic engineering is the process of moving genes from the chromosomes of one organism to those of another organism.

Recombinant DNA is formed by joining DNA

molecules.from two different organisms