Do Now
1. Thinking back to Friday, write to the
best of your ability what we did in
the lab on Friday. This should be
written in complete sentences. We
will be debriefing the lab for a bit
before we begin today’s lesson.
2. If you weren’t here, write what you
did this weekend.
Announcements
• Short quiz on Friday covering DNA and RNA.
• What would you guys think about the idea of
doing a lab in class on say a Tuesday, and then
inviting your parents and doing the lab with
them that night/different day?
Today
• Goin’ back to RNA
– Why? Because we sped through this to get to
DNA and our lab.
• RNA Artwork
RNA
• RNA carries the info from DNA to a ribosome
where amino acids are brought together to
make a protein.
• Three types
– Who can remember what these stand for?
• mRNA
• rRNA
• tRNA
Transcription
• Process of transferring information from DNA
to RNA is called transcription.
• Four types of nucleotide bases
– Guanine, Cytosine, Adenine, Uracil
• During transcription, DNA is used as a
template only to make a complementary
strand of RNA.
– ONLY INDIVIDUAL GENES
Transcription vs. replication
• Transcription: only ONE strand of DNA is
transcribed.
• At end of transcription, DNA closes back up.
• Can lead to a lot of one section of DNA being
transcribed (AKA LOTS OF COPIES)
Translation
• To make proteins, cells have to translate
language of nucleotide bases into language of
amino acids.
• Three specific bases equal one amino acid
• The actual assembly of the amino acids in
their proper sequence is the translation
• Translation involves all type of RNA
Translation Analogy
•
•
•
•
DNA = Cookbook
mRNA = recipe for making proteins
rRNA = stove
tRNA = gatherer of ingredients
• What do you think I mean by this?
• Translation begins when ribosome attaches to
mRNA
• tRNA molecule with an amino acid matches on
mRNA
• The ribosome attaches on amino acid to another
as it move along the mRNA
• The tRNA molecules are released after the amino
acids they carry are attached to the growing
chain of amino acids.
• Ribosome completes the translation when it
reaches the end of the mRNA stand.
Activity
• Grab a textbook and open to page C140.
• You are going to be drawing that picture
showing what happens during translation.
• You guys did such a great job on the last
drawing activity, let’s do it again!