1. Take 5
What is the product of DNA replication?
As DNA unzips to be copied, what type of bond must be broken?
The backbone of a DNA molecule is made of which two components?

2. Protein Synthesis: Part 1 (Transcription)
Ch 11

3. Synthesizing Proteins or “MAKING” PROTEINS
Protein Synthesis means
Synthesizing Proteins or
“MAKING” PROTEINS

4. learn how proteins are made.
The GOAL is to:
learn how proteins are made.

5. Protein Synthesis
can be broken down into two stages:
Transcription
Translation

6. DNA mRNA Proteins TRANSCRIPTION TRANSLATION 1st PROCESS 2nd PROCESS 13

7. Reads and copies a section of DNA (AKA gene) and converts it into mRNA
Transcription
Reads and copies a section of DNA (AKA gene) and converts it into mRNA
(A gene codes for a protein)

8. Let’s compare
DNA and RNA

9. DNA
RNA
Sugar = deoxyribose
Sugar = ribose
Double helix (2 strands)
Single strand

10. DNA
RNA
Location: nucleus
Location: everywhere (mRNA: nucleus)
Bases: A, C, G, T
Bases: A, C, G, U (Uracil)

11. DNA
RNA
Function: simply stores genetic info
(instructions to make proteins)
Function: many functions, all used to assemble proteins

12. Three types of RNA
MESSENGER RNA (mRNA)
TRANSFER RNA (tRNA)
RIBOSOMAL RNA (rRNA)

13. MESSENGER RNA “mRNA” single strand contains genetic info
is transported out of nucleus

14. TRANSFER RNA “tRNA” single strand folded like a hairpin
binds specific amino acids

15. RIBOSOMAL RNA “rRNA” single strand found in ribosomes
ribosomes are made up two pieces of rRNA

16. RNA STRAND

18. Let’s look at
TRANSCRIPTION
“The first process”

19. DOUBLE HELIX SPREADS APART
mRNA
DOUBLE HELIX SPREADS APART
RNA POLYMERASE copies the gene by attaching RNA nucleotides
The product is called mRNA
mRNA

20. Here the DNA is split open and a mRNA strand is being made

21. Here the DNA is split open and a mRNA strand is being made

22. RNA POLYMERASE ADDS ON RNA NUCLEOTIDES TO MAKE mRNA
NOTICE:
RNA POLYMERASE ADDS ON RNA NUCLEOTIDES TO MAKE mRNA

23. Then the newly constructed mRNA undergoes “processing”
The mRNA then leaves the nucleus to enter the next process “translation”
mRNA

24. DNA RNA DNA G C A T C G U A C G T A “promoter” sequence3’ 5’ G C A T C G U A C G T A
“promoter” sequence
(Signals where to begin)
“terminator” sequence
(where to end) 5’ 3’

25. RNA processing includes
cutting out meaningless DNA (aka introns)
Adding a cap on the tip (aka GTP cap)
Adding on A-A-A-A on the end (aka Poly-A tail)

26. Introns contain meaningless DNA+
Introns contain meaningless DNA =
Only the important, USEFUL DNA

27. Add on a GTP cap Tack on a poly-A tail
A-A-A
mRNA
Add on a GTP cap
Tack on a poly-A tail
You are finished processing the mRNA. It can now leave the nucleus.

29. Describe what is happening here and who is involved