1. Transcription Modeling
Objectives
Agenda
Describe and sketch the steps and products of DNA replication.
Identify the difference between the structure of DNA and RNA.
List the three types of RNA.
Summarize the process of transcription.
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DNA Quiz
Transcription Notes
Transcription Modeling
Padlet

2. RNA Transcription & Protein Synthesis
From DNA to Proteins

3. Protein Synthesis Overview
The information in DNA is used to make proteins. These proteins are used for a variety of purposes within the body.
This is called the
CENTRAL DOGMA of molecular Biology

4. Protein Synthesis Overview
However...
Where is DNA located?
But ribosomes are located where?
How can the information get from the nucleus to the ribosomes in the cytoplasm?
nucleus
cytoplasm

5. Protein Synthesis Overview
The solution is that the cell makes a temporary copy of the DNA. The temporary copy is called RNA.

6. Ribonucleic Acid
RNA, or Ribonucleic Acid, is single stranded and made of nucleotides, just like DNA
Structure of RNA nucleotide:
1. Ribose sugar
2. Phosphate
3. Nitrogen Bases
Adenine (A)
Guanine (G)
Cytosine (C)
Uracil (U): NOT Thymine (T)

7. Types or RNA
Messenger RNA (mRNA): Acts as messenger, carries a copy of the directions from DNA to the ribosome

8. Types or RNA Ribosome tRNA Ribosomal RNA (rRNA): makes up the ribosome
Transfer RNA (tRNA): transfers (adds) an Amino Acid to the ribosome
Amino Acid
tRNA
Ribosome
Anti-codon

9. RNA and Protein Synthesis
DNA
RNA
similarities
Made of Nucleotides (Phosphate, Sugar, Nitrogenous Base)
Made in Nucleus
A, G, C
differences
differences
Double stranded
Single stranded
Only found in nucleus
Can be found in nucleus or cytoplasm
thymine
Uracil
deoxyribose
Ribose
Long-term
Short term (temporary copy)

10. Transcription Transcription is the first step in protein synthesis.
Purpose: make RNA, a copy of the information contained in DNA
Occurs in the nucleus
DNA is again unzipped, this time by RNA Polymerase.
Reversibly breaks Hydrogen bonds
3 things needed to get started:
DNA
Free RNA Nucleotides
RNA Polymerase
DNA

11. Step 1: Initiation RNA polymerase attaches to a promoter region of DNA
Draw This image
RNA polymerase attaches to a promoter region of DNA
Called the TATA box
RNA Polymerase

12. Step 2: Elongation
Draw This image
RNA polymerase opens the DNA helix. It makes a little bubble. One strand will act as a template.
RNA polymerase moves down the DNA molecule attaching complementary RNA nucleotides as it goes.
Everything is the same as DNA replication except:
The DNA A pairs with RNA U
Template Strand
Complimentary Strand

14. Step 3: Termination
Transcription stops when RNA polymerase reaches the terminator region of DNA.
Draw This image
RNA Polymerase
Stays in the nucleus

15. RNA Polymerase makes mRNA RNA Polymerase breaks H-bonds
Deoxy-ribose P
Thymine
Cytosine
Adenine
Ribose P
Uracil
Ribose P
Guanine
Uracil
Adenine
Adenine
Deoxy-ribose P
Guanine
Thymine
---H---
Transcription
Ribose P
Guanine
RNA Polymerase makes mRNA
Strands move apart
mRNA exits nucleus
RNA Polymerase breaks H-bonds
DNA re-coils
---H---
Ribose P
Adenine
---H--- P

16. Fill in the missing information

17. RNA Editing
Many RNA molecules require a bit of editing before they leave the nucleus.
mRNA: a cap and tail are added to the ends
Introns- not involved in coding for proteins
These get taken out in a process called splicing
Exons- are expressed, used to make proteins