1. DNA Replication & Protein Synthesis
Designed by Mr. Gaccione

2. BioTech: DNA Review

3. The Size of DNA...
DNA is located in the nucleus in the form of chromosomes. If the DNA of one cell is stretched out, it makes a 7 ft. long string. There are 5 trillion cells in the human body. If you connected all the DNA together, it would be long enough that it would take light over 10 hours to travel its length.

4. The Size of DNA... Chromosomes contain a single, long piece of DNA
A chromosome is about mm long
The DNA is about 4 cm long
This is 10,000x longer than the chromosome
Thus DNA must be wrapped tightly to fit into cells
Imagine fitting 900 yards (300m) of rope into a backpack.

5. The Size of DNA...
The DNA molecule looks like a ladder that has been twisted.
The DNA molecule is
made from two strands,
twisted together in a
double helix.
Watson & Crick –
created the double
helix model for DNA.

6. The Structure of DNA
DNA is a long molecule made up of repeating units called nucleotides. Each nucleotide is made up of three parts: 1. phosphate group 2. carbon sugar (deoxyribose) 3. nitrogen base

7. Repeating Nucleotides
The sides of the DNA ladder(backbone) is formed by phosphate and sugar groups.
The nitrogenous bases are
the rungs of the DNA ladder.
DNA is 250 million nitrogen
bases long.
RNA is 3000 nitrogen bases long.

9. Nitrogenous Bases Purines (bigger) – Pyrmidines (smaller) –
There are four kinds of nitrogenous bases.
They are divided into two classes:
purines and pyrmidines
Purines (bigger) –
Adenine and Guanine
Pyrmidines (smaller) –
Cytosine and Thymine

10. Chargaff’s Rules
Chargaff discovered how the nitrogenous bases bond together.
Adenine always bonds with Thymine Cytosine always bonds with Guanine

11. DNA

12. Hydrogen bonding

13. DNA Sequence
The particular order of the nitrogen bases is called the DNA sequence.
This sequence makes each individual unique.
An elm tree, eel & an elephant has the same DNA, but what makes them different is the order of the bases.

14. DNA & Genes Each chromosome carries 2,000 genes.
23 chromosomes = 30,000 to 40,000 genes
This is known as “The Human Genome”
Genes are locations on chromosomes that give us our traits.
Many of these are common to all human beings.
So, 99.9% of your DNA is identical to everyone else's.

15. DNA & Genes The remaining 0.01% influences the differences between us.
height, hair color and
susceptibility to a particular disease
Environmental factors, such as lifestyle (smoking and nutrition) also influence the way we look and our susceptibility to disease.

16. Mutations Mutations are caused by mutatgens. Examples of mutagens:
UV rays, smoking & radiation
Mutations are mistakes in the nitrogen bases or in the DNA sequence.

17. Point Mutation C

18. Thymine mutation Caused by exposure to UV light.
2 adjacent thymine residues become covalently linked.

19. Mutations RNA polymerase adds ribonucleotides not deoxynucleotides
RNA polymerase does not have the ability to proofread what they transcribe
RNA will have an error 1 in every 10,000 nucleotides
DNA will have an error 1 in ten million nucleotides)

20. DNA Replication DNA replication makes an exact copy of the strand, complete with 1 old and 1 new strand.
Step 1
DNA unwinds & unzips with the help of DNA polymerase
Step 2
Each strand of the parent DNA is used as a
template to make the new daughter strand.
Step 3
Free floating nucleotides are added by DNA polymerase.

21. DNA Replication C T A C C G G G A T G G C C T A T

22. DNA to mRNA to Protein
･DNA acts as a “manager” in the process of making proteins.
･DNA is the template or starting sequence that is copied into RNA that is then used to make a protein.

23. RNA differs from DNA Ribose is the sugar rather than deoxyribose.
Uracil instead of
Thymine
Adenine, Guanine
Cytosine stay the same.
3. Single stranded

24. Three Different RNAs GUA---UUC---GUU---AGU---UGA
messenger RNA (mRNA) – takes a message or letter code(codon) from DNA
GUA---UUC---GUU---AGU---UGA
ribosomal RNA (rRNA) –
meeting place for three RNAs
3. transfer RNA (tRNA) – brings
anti-codon & amino acid
Ribosome

25. Protein Synthesis -2 Steps Transcription & translation
First step in protein synthesis
mRNA transcribes a message (code) from DNA
Occurs in the nucleus

26. Protein Synthesis Transcription
DNA
Cytoplasm
Nucleus
RNA
Transcription
Export G
AAAAAA

27. Protein Synthesis -Transcription
Step 1
DNA unwinds & unzips with the help of RNA polymerase
Step 2
Only one strand of the parent DNA is used as a
template to make mRNA.
Step 3
Free floating nucleotides are added by RNA polymerase, making mRNA.

28. Protein Synthesis-Transcription

29. Protein Synthesis Transcription

30. Protein Synthesis -Transcription aking mR from D templateU A C C G G A U A

31. Protein Synthesis -Translation
Amino
acid
Translation
Goal: to make a protein
Second step in protein synthesis
All three RNAs meet
(mRNA, rRNA & tRNA)
Occurs in the cytoplasm
UAC
--UUC--GUU--AUG--
Amino
acid
--AUG--
tRNA brings anti-codon
& amino acid
Anti-codon

32. Protein Synthesis - Translation Draw and label the boxes, tRNA, mRNA & rRNA

33. Translation rRNA & mRNA are in the cytoplasm. Where is tRNA???
Amino
Acid?
Amino
Acid?
Amino
Acid?
Met
Amino
Acid?
Amino
Acid?
Phe
Val
Ser
Stop!
Ribosome
ANTI-
CODON?
UAC
ANTI-
CODON?
AAG
CAA
UCA
ANTI-
CODON?
ACU
ANTI-
CODON?
ANTI-
CODON?
- AUG--UUC--GUU--AGU--UGA 5’ 3’
rRNA & mRNA are in the cytoplasm. Where is tRNA???

34. ? ? ? ? ? ? ? ? ? ? ? Protein Synthesis -Translation Review tRNA rRNA
mRNA
mRNA ? ?
rRNA
Amino acid ?
mRNA ? ? ?
mRNA
tRNA
tRNA

35. Protein Synthesis -Translation Review
Translation is the meeting of all three RNAs (mRNA, rRNA & tRNA).
It takes place in the cytoplasm.
The goal is to string together amino acids to form a protein.
Proteins make up our skin, blood, muscles, heart, enzymes, stomach lining & intestinal linings.

36. Protein Synthesis - Key Words
Transcription
DNA
Double Helix
3’-5’ strand
5’-3’ strand
Phosphate Group
Deoxyribose Sugars
Ribose sugars
Hydrogen Bonds
RNA polymerase Nucleus
Nuclear pore ER
Complementary base pairs
rRNA mRNA tRNA