Download 7b. Transcription and Translation

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
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?
TU
Base Pairing in DNA and RNA
• Nitrogen Base Pairs in DNA:
A–T
C–G
• Nitrogen Base Pairs in RNA:
A–U
C–G
III. 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
______________
IV. Comparing DNA and RNA
IV. Comparing DNA and RNA
DNA
BOTH
RNA
V. 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
V. Protein Synthesis
Two Parts to synthesizing proteins
1. Transcription- Turns DNA into RNA
2. Translation- Turns RNA into Amino Acids/Proteins
Codon- 3 letter (nitrogen base) code from RNA
Amino Acid- building blocks for proteins
*Each codon is a code for an amino acid*
VI. 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
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
Universal Codon Chart
IX. Comparing Transcription and Translation
Job
Where
in the
cell?
Transcription
DNA  RNA
Translation
RNA  Proteins
Nucleus
Ribosome
(Cytoplasm)