7b. RNA and Protein synthesis
I. What is RNA?
• RNA  Ribonucleic Acid
• Different kinds of RNA
• mRNA – carries the instructions for making
proteins from the nucleus to the ribosome
• tRNA- brings amino acid to ribosome
Character in
the story?
II. RNA Structure
• Single Stranded
• Base Unit/ Subunit: Nucleotides
• Phosphate
• Sugar (Ribose)
• Nitrogen Base
II. RNA Structure
• Four Nitrogen bases in DNA: • Four Nitrogen bases in RNA:
• Adenine
• Guanine
• Cytosine
• Thymine
• Adenine
• Guanine
• Cytosine
• Uracil
What is different from DNA?
ThymineUracil
III. Comparing DNA and RNA
DNA
BOTH
RNA
III. Comparing DNA and RNA
III. Comparing DNA and RNA
DNA
BOTH
RNA
IV. Protein Synthesis
• Synthesis- to make larger complex molecules out of
simple ones
• Basic unit of proteins- Amino Acids
• Protein synthesis- Combining amino acids into
proteins
SER
GLU
Amino
Protein
Acids
PRO
GLY
IV. Protein Synthesis
Two Parts to synthesizing proteins
1. Transcription- Turns DNA into RNA
2. Translation- Turns RNA into Amino Acids/Proteins
V. Transcription
• Transcribe- To write
• Transcription- Turning DNA into RNA
(Writing out instructions)
Process
1. Helicase “unzips” DNA.
2. RNA Polymerase makes new
copies of strands.
3. mRNA is allowed to leave
the nucleus.
HELICASE
RNA
Polymerase
VI. Base Pairing in DNA and RNA
• Base Pairs in DNA:
• Base Pairs in RNA:
A–T
T–A
G–C
C–G
A–U
T–A
G–C
C–G
Base Pairing Practice
A-T-T-G-C-C-C-T
______________
A-A-C-A-A-G-T-C
______________
T-G-G-G-C-G-C-G
________________
T-A-T-T-C-C-C-G
_____________
T-G-C-A-C-A-T-G
______________
T-T-G-T-C-T-G-G
______________
VII. Translation
Translation- ribosome turns RNA into amino acids chains (proteins)
Codon- 3 letter (nitrogen base) code from RNA
Amino Acid- building blocks for proteins
*Each codon is a code for an amino acid*
VII. Translation
Translation- turns RNA into amino acids chains (proteins)
1. mRNA attaches to Ribosome
2. Ribosome translates every 3
nitrogen bases (codon) into amino
acids, which are brought to
ribosome by tRNA.
3. Ribosome binds (attaches) amino
acids into a chain.
4. Chain of amino acids is released as
a protein.
PRO
GLU
SER
GLY
VIII. Universal Codon Chart
AUG- ______ GGG- ______ CUA- ______ UAA- ______
IX. Comparing Transcription and Translation
Job
Where
in the
cell?
Transcription
DNA  RNA
Translation
RNA  Proteins
Nucleus
Ribosome
(Cytoplasm)