This document discusses RNA and protein synthesis. It contains the following key points: - RNA is similar to DNA but is single-stranded and contains the sugar ribose instead of deoxyribose. There are three main types of RNA: mRNA, tRNA, and rRNA. - mRNA carries DNA's genetic message from the nucleus to the ribosomes. tRNA carries amino acids to the ribosome. rRNA makes up the ribosomes and helps assemble proteins. - During transcription, RNA polymerase uses DNA as a template to create mRNA. During translation, the ribosome reads the mRNA codon by codon and bonds amino acids together to form a protein based on the mRNA sequence. tRNA carries the correct amino

1. Unit 5:
DNA & Protein Synthesis
Section 3: RNA & Protein Synthesis
Biology
Mrs. DeFord

2. RNA
• Like DNA, RNA is a nucleic acid made up of
nucleotides. Recall that nucleotides have three
parts:
–pentose (5-carbon) sugar
–phosphate group
–nitrogenous base

3. DNA vs RNA
nuclear
*mitochondrial
TYPES
mRNA = messenger
tRNA = transfer
rRNA = ribosomal
never leaves
nucleus
LOCATION
mRNA is assembled
in nucleus and
moves to cytoplasm
(leaves nucleus)

4. DNA vs RNA
double-stranded
sugar = deoxyribose
bases = A adenine
T thymine
C cytosine
G guanine
STRUCTURE
single-stranded
sugar = ribose
bases = A adenine
U uracil
C cytosine
G guanine
replicates and
stores genetic
information
FUNCTION
converts DNAs
genetic information
to a format used to
build proteins

5. Types of RNA
1. Messenger RNA
(mRNA)
Carries DNAs
message from the
nucleus to the
ribosomes.

6. Types of RNA
2. Ribosomal RNA
(rRNA)
Makes up part of the
ribosome. Helps read
mRNAs message
and assemble
proteins.
Ribosomes are the cell’s protein factories.

7. Types of RNA
3. Transfer RNA (tRNA)
Carries the correct
amino acids to the
ribosome so that they
can be added to the
growing protein
chain.

9. Central Dogma of Molecular Biology

10. Protein Synthesis - Transcription
1. The enzyme RNA polymerase unwinds DNA and
guides the creation of mRNA; as the DNA unwinds,
RNA polymerase uses one strand as a template
2. Nucleotides are added into a complementary strand
of mRNA based on the DNA code
DNA: AATTGGCAC
mRNA: UUAACCGUG
3. The mRNA strand leaves the nucleus and goes to
the ribosome for translation

11. Protein Synthesis - Translation
1. mRNA is read by rRNA (rRNA makes up the
ribosome)
2. mRNA is read 3 bases at a time. Every 3 bases on
mRNA codes for 1 amino acid (these triplet bases
on mRNA are called codons)
3. Once the start codon is read, tRNA carries the
correct amino acid to the ribosome using the
anticodon (anticodons are triplet bases on tRNA
that are complementary to mRNA)
mRNA codon: UUC
tRNA anticodon: AAG

12. Protein Synthesis - Translation
4. Amino acids are brought until the entire mRNA is
read. Each tRNA drops off one amino acid then
goes into the cytoplasm to grab another.
5. The ribosome bonds each amino acid together
using a peptide bond, creating a protein (also called
a polypeptide).
6. Eventually the stop codon is reached and the final
amino acid is added.

15. Reading Codon Charts
• One skill you will need
for the upcoming test
and the EOC is to
create a protein when
given a DNA code.
• Remember, the bases
for
– DNA are ATCG
– RNA are AUCG

16. Reading Codon Charts
• CCC =
• GCA =
• AUG =
• AGG =
• ATG =

17. Steps for Practice
1. When given a DNA code, you must first transcribe
it into mRNA via complementary base pairing.
DNA: T A C T T G A A C T A A
mRNA:
2. Next, break the mRNA into codons (3 letters).
3. Use the codon chart to find the amino
acids…remember the START codon begins
translation.

18. Independent Practice
DNA: T A C A T T T A A C G G G C C
mRNA:
Amino acid:
DNA: A A T T A C T C C G G A T A T
mRNA:
Amino acid: