Protein Synthesis: Transcription and Translation

• Describe the functions and types of RNA

• Describe the basic processes of transcription and translation and the role of enzymes in producing proteins.

§Nucleic Acid

§Double Stranded

§Double Helix Shaped

§Deoxyribose (sugar in nucleotide)

§Nitrogen Bases:

§A, T, G, C (remember, T is specific to DNA)

§Replicates and stores genetic information

§Found in nucleus of eukaryotes

§Nucleic Acid

§Single Stranded

§Ribose (sugar in nucleotide)

§Nitrogen Bases:

§A, U, G, C (U is specific to RNA)

§Transfers genetic information from DNA into a format used to build proteins

§Moves from nucleus to cytoplasm

3 Types of RNA
1. Messenger RNA (mRNA)
RNA that carries genetic code from nucleus to ribosomes
2. Ribosomal RNA (rRNA)
RNA that is in ribosomes to help assemble proteins
3. Transfer RNA (tRNA)
RNA that carries amino acids to ribosomes to build proteins

Genes are instructions for making specific proteins, but they do not build the proteins directly.

The flow of information within a cell goes from DNA to RNA to protein.

The two major steps in this passing of information are transcription and translation.

 What: DNA is used to synthesize(make) mRNA molecule.

 Where: Nucleus

 Who’s involved: RNA polymerase (enzyme that makes mRNA by matching nucleotides), mRNA, DNA

 Why: To build mRNA molecule used to transfer instructions for building protein

 What happens afterwards:  mRNA goes to a ribosome for Translation.

  What: Ribosome (rRNA) attaches mRNA molecule and reads mRNA nucleotide sequence in groups of 3s (called codons) in order to assemble a protein. tRNA brings amino acids required to be linked into polypeptide(protein).

 Where: Ribosome and cytoplasm

 Who’s involved: all types of RNA, ribosome, and amino acids

 Final product: Protein!

Translation

1. Replication - make more DNA
2. Transcription - DNA to RNA
3. Translation - RNA to Protein
4. Proteins - Control the body

Compare and contrast the two processes involved to create proteins. Make sure to address purpose, location, molecules involved, etc.