• Single nucleotide strand
• Sugar: Ribose• 4 Bases:
–A: Adenine–G: Guanine–C: Cytosine–U: Uracil
• U replaces T• Three Types of RNA
• mRNA
• Function: Copies the DNA code and moves to a ribosome
• Link between DNA & Protein
• Allows ribosome to create a protein
• Location: Starts in nucleus… moves to ribosome
• tRNA• Function: Transfers amino acids from the cytoplasm to
the ribosome• Ribosome will link amino acids together to form a protein• Location: Cytoplasm
Amino acidProline
Amino acidSerine
Transcription• Defined: Process of making mRNA from DNA
• Step 1: RNA Polymerase separates the DNA nucleotides
• Step 2: Free floating RNA nucleotides match with the DNA
Reminder: U replaces T
• Step 3: mRNA breaks free in separate pieces
• Step 4: mRNA processing takes place
– Unused portions (introns) are removed and the used portions (exons) bond together
• Step 5: Final mRNA strand travels to ribosome
• Step 6: DNA recombines to be used again
U|
G|C|A|A|G|U|C|A|U|U|C|
G|
DNA vs. RNA• Double Stranded
• Sugar: Deoxyribose
• Bases: A T C G
• Location: Nucleus
• Single strand
• Sugar: Ribose
• Bases: A U C G
• Location: Nucleus & Cytoplasm
Review• Name three different ways that DNA and RNA differ.• Which RNA:
– is found inside the nucleus?– transports amino acids to the ribosome?– exits the nucleus to the ribosome?– copies the DNA code?– makes up the structure of ribosomes?
• Perform transcription by using the following piece of DNA. Introns are underlined. Write the final strand of mRNA created.
T A C C G T A C A A T G G G A T C