Station 1

What is the purpose of genes?

What is the purpose of RNA?

In what 2 ways is RNA different from
DNA?
Station 2

What are the three types of RNA?
 What
 How
do they stand for?
are they different?
Stage 3

What is transcription?

What is RNA polymerase’s role in
transcription?

What is a promoter?

Transcribe: ATGTGGCTA
Station 4

What happens when RNA polymerase
binds to a promoter?

How is transcription different from DNA
replication?

What determines which nucleotide is
added next to form an RNA chain?
Station 5

What is the purpose of a termination
signal?

What are transcripts?

What happens to mRNA after it is made?
Station 6

What are proteins made up of?

How many amino acids are there?

What does the sequence of amino acids
tell us?
RNA



DNA Replication
The strand that is copied to form a new strand is called a
template
In replication of a double-stranded DNA, both original
(parental) DNA strands are copied
When copying is finished, you have two separate helices,
each consist of one of the original strands plus its copy.
Do Now:

What is the complement?
 AGTCGGAT
 TAGCCTAC
 CTGAGGAT
RNA

Also made up of nucleotides
 Sugar

molecule: Ribose
Uracil (U) pairs with Adenine
(A) in RNA
Types of RNA

Messenger RNA (mRNA)
 Carries

info from DNA to the cytosol
Transfer RNA (tRNA)
 Binds
to specific amino acids
 Aids in translation (RNA proteins)

Ribosomal RNA (rRNA)
 Makes
up ribosomes
Protein Synthesis
Genes are made up
of DNA.
 Genes code for
proteins.
 Proteins are made
from long chains of
amino acids.

How do we get from
DNA to proteins?
STEP 1: Transcription
DNA is transcribed (copied) into RNA.

RNA binds to a promoter.
 Single
gene in eukaryotes
 Several genes in
prokaryotes

Where RNA polymerase
binds, the DNA separates.

DNA is transcribed until the
termination signal is
reached. At this point the
RNA molecule releases the
DNA
Transcription

DNA Strand
ATC AGG TAC GGA

What’s the mRNA strand?
Protein Synthesis

DNA Strand
ATC AGG TAC GGA

Check you answer. Did you have:
UAG UCC AUG CCU
Proteins

Composed of amino acids

20 different types of amino acids

The sequence of the amino acids
determines how the polypeptide twists and
folds (shape).
Step 2: Translation

mRNA is converted into an amino acid sequence.

The mRNA sequence is read in groups of 3 bases
(codons) and the proper amino acids are found and
linked together.
How do you know the right amino
acid to use?
Let’s Make our own strand

DNA Strand is:
TAC GTA CTT ATT
mRNA strand is:

Codes for amino acids:

Check your strand:
DNA Strand is:
TAC GTA CTT ATT
 mRNA strand is:
AUG CAU GAA UAA
 Codes for amino acids:
MET HIS GLU STOP
