DNA Replication, RNA Structure & Function, and Compare DNA & RNA

1. DNA Replication, RNA Structure & Function, and Compare DNA & RNA

DNA Replication, RNA Structure
& Function, and Compare DNA &
RNA
CIE Biology Jones
pp 111-122
G11 Biology 2017-2018
Learning Objective
1. Describe the process of DNA replication based on Chargaff rules.
2. Distinguish between types of RNA structure and function.
3. Compare the structure of RNA and DNA.

2.

Success Criteria
1. Can apply Chargaff’s rule to calculate a correct number of X bases
presented from the information taken from Y bases. Know and
explain two rules:
1. Quantity A = Quantity T
• Quantity G = Quantity C
2. Relative quantity of DNA varies from one sample to another one
particularly in relative quantity of reasons ATGC
2. Know and understand the process of DNA replication. Apply
knowledge in completing diagram. Use correctly and explain terms.
3. Analyze structure of RNA and DNA molecules. Find similarities and
differences. Complete the table correctly.
Meselson and Stahl (watch until 5.18 min) https://www.youtube.com/watch?v=4gdWOWjioBE&t=52s
Professor Dave DNA replication (6.14 min) https://www.youtube.com/watch?v=9kp9wiYMQUU
Mrs Cooper DNA replication (13 min) https://www.youtube.com/watch?v=6NhDY3IDp00

3. Terminology – Replication flash cards https://quizlet.com/140046226/as-biology-dna-replication-and-the-genetic-code-flash-cards

English
Google Russian
Origin, Origin of Replication
Replication fork
Chargaff’s Rules
Sense, coding, non-template
Antisense, non-coding, template
Conservative, Semi-conservative
Topoisomerases (gyrases)
DNA helicase
Single Stranded Binding Proteins (SSBP)
Nucleases – break down DNA
Okazaki fragments
DNA polymerase III
DNA polymerase I
RNA Primase
DNA Ligase
Replication bubbles
Daughter strand
Continuous, discontinuous
Происхождение, Происхождение репликации
Репликационная вилка
Прайс-лист
Смысл, кодирование, не шаблон
Антисмысловой, некодирующий, шаблон
Консервативный, полуконсервативный
Топоизомеразы (гираны)
ДНК-геликаза
Однослойные связывающие белки (SSBP)
Нуклеазы - разрушить ДНК
Окадзаки
ДНК-полимераза III
ДНК-полимераза I
РНК Primase
ДНК-лигаза
Репликационные пузыри
Дочерняя нить
Непрерывный, прерывистый

4. When does DNA replication occur in a eukaryotic cell?

5. Question:

•When and where does DNA
Replication take place?
S phase of
interphase of
the cell cycle
IN
Eukaryotic
cells

6.

Mechanisms of DNA Replication
Meselsohn and Stahl Experiment
There were three theories of how DNA might replication.

7. Scientists had three theories of how DNA Replicated.

8. Meselson and Stahl – How does DNA replicate? In class  (watch until 5.18 min)

Meselson and Stahl – How does DNA replicate?
In class
(watch until 5.18 min) https://www.youtube.com/watch?v=4gdWOWjioBE&t=52s
Bacteria was grown on nutrient 15N
as nitrogen source. Gen = 0
Bacteria was grown on nutrient 14N
as nitrogen source. Gen = 1-4
14 N
15 N
Bacteria was grown until all DNA contained 15N as nitrogen source. Density = 100% Heavy 15N
Then bacteria was grown using only 14N – as nitrogen source.
Generation 0 Density = 100% of 15N
Generation 1 Density = 100% of 15N +14N mixed equally as one molecule.
Generation 2 Density = 50% of 15N + 14N and 50% of only 14N
Generation 3 Density = 25% of 15N + 14N and 75% of only 14N
Generation 4 Density = 12% of 15N + 14N and 88% of only 14N

9.

Same experiment –
different graphic
The experiments
of
Meselsohn and
Stahl
to support semiconservative
replication.

10.

11. DNA Replication - Semiconservative

12.

Watch this now Professor Dave DNA replication
(6.14 min) https://www.youtube.com/watch?v=9kp9wiYMQUU
DNA
Replication
Replication Bubbles
Eukaroyotic genomes are
so large that replication
must occur simutaniously
on many parts of the
strand to ensure that it is
complete.
Semiconservative-Why does DNA replicate?
-During what process does
replication take place in a eukaryotic cell?
one old and one new strand both
are identical to the parent strand.

13. Since DNA is antiparallel – it must replicate continuously and discontinuously.

14.

Steps of DNA Replication
1. Topoisomerase binds and relaxes the double helix.
2. Helicase unwinds the parental double helix.
3. Single stranded binding proteins stabilize the unwound parental DNA.
4. The leading strand is synthesized continually in the 5’ to 3’ direction by DNA polymerase III.
5. The lagging strand is synthesized discontinuously. Primase synthesizes a short RNA primer, which is extended by DNA
polymerase I to form and Okazaki fragment.
6. After the RNA primer is replaced by DNA polymerase, DNA ligase joins the Okazaki fragment to the growing chain.

15. DNA Replication

• Origins of replication
1. Replication Forks: hundreds of Y-shaped
regions of replicating DNA molecules
where new strands are growing.
5’
3’
Parental DNA Molecule
Replication
Fork
3’
5’

16. DNA Replication

• Origins of replication
2. Replication Bubbles:
a. Hundreds of replicating bubbles
(Eukaryotes).
b. Single replication fork (bacteria).
Bubbles
Bubbles

17. DNA Replication

• Strand Separation:
1. Topoisomerase: enzyme which relieves
stress on the DNA molecule by allowing free
rotation around a single strand.
Enzyme
DNA
Enzyme

18. DNA Replication

• Strand Separation:
2. Helicase: enzyme which catalyze the unwinding and
separation (breaking H-Bonds) of the parental double
helix.
3. Single-Strand Binding Proteins (SSBP): proteins
which attach and help keep the separated strands
apart.

19. DNA Replication

• Priming:
2. RNA primers: before new DNA strands can form,
there must be small pre-existing primers (RNA)
present to start the addition of new nucleotides (DNA
Polymerase).
3. Primase: enzyme that polymerizes (synthesizes)
the RNA Primer.

20. DNA Replication

• Synthesis of the new DNA Strands:
1. DNA Polymerase III: with a RNA primer in place,
DNA Polymerase (enzyme) catalyze the synthesis of a
new DNA strand in the 5’ 3’ direction.
5’
3’
Nucleotide
DNA Polymerase III
RNA
Primer
5’

21. DNA Replication

• Synthesis of the new DNA Strands:
2.
Leading Strand: synthesized as a
single polymer in the 5’ to 3’ direction.
5’
3’
5’
Nucleotides
DNA Polymerase III
RNA
Primer

22. DNA Replication

• Synthesis of the new DNA Strands:
3. Lagging Strand uses DNA polymerase I: is also
synthesized in the 5’ to 3’ direction, but discontinuously
against overall direction of replication.
Leading Strand
5
’
3’
DNA Polymerase I
RNA Primer
3’
5’
5’
3’
3’
5’
Lagging Strand

23. DNA Replication

• Synthesis of the new DNA Strands:
4.
Okazaki Fragments:
segments on the lagging
Okazaki Fragment
3’
DNA
Polymerase
RNA
Primer
5’
Lagging Strand
series of short
strand.
3’
5’

24. DNA Replication

• Synthesis of the new DNA Strands:
5. DNA ligase: a linking enzyme that
catalyzes the formation of a covalent bond
from the 3’ to 5’ end of joining stands.
Example: joining two Okazaki
fragments together.
DNA ligase
5’
3’
Okazaki Fragment 1
Lagging Strand
Okazaki Fragment 2
3’
5’

25. DNA Replication

• Synthesis of the new DNA Strands:
6. Proofreading: initial base-pairing
errors may be corrected by
DNA polymerase I or III.

26.

G11 DNA RNA Protein Notes
Name ____________________________________________________11_______
The Central Dogma of Biology
DNA mRNA
mRNA amino acid
DNA DNA
REPLICATION: DNA DNA
NUCLEOTIDE
Deoxyribose
Phosphate
Nitrogen base
NITROGEN BASES
G = Guanine
C = Cytosine
A = Adenine
T = Thymine
OCCURS
Mitosis/Meiosis
Interphase (S)
Nucleus-Eukaryote
Cytoplasm-Prokaryote
ENZYMES REQUIRED
Helicase- Unwinds and breaks the hydrogen bonds(unzips) of the DNA double helix
Topoisomerase (DNA Gyrase) – stabilizes the helix as it is unwound and unzipped by helicase.
Single-stranded binding proteins (SSBP) – bond to separated DNA strands to stabilize them – hold them apart.
DNA Ligase – Joins together Okazaki fragments on the laggings strand.
DNA polymerase I – replaces RNA primers on the lagging strand with DNA nucleotides and proofreads
DNA polymerase III – Adds DNA nuleotides in a 5’ 3” direction on both strands, proofreads.
DNA primase – Adds RNA nucleotides to form primers on the lagging strand of DNA.

27.

TRANSCRIPTION: DNA RNA
DNA :NUCLEOTIDE
Deoxyribose
Phosphate
Nitrogen base
NITROGEN BASES
G = Guanine
C = Cytosine
A = Adenine
T = Thymine
RNA :NUCLEOTIDE
Ribose
Phosphate
Nitrogen base
NITROGEN BASES
G = Guanine
C = Cytosine
A = Adenine
U = Uracil
OCCURS
Mitosis/Meiosis
Interphase
Nucleus
OCCURS
mRNA carries out of
nucleus to the
cytoplasm where it
is attached to a ribosome

28.

DNA DNA
DNA mRNA
mRNA amino acid
Mitosis / Meiosis
TRANSLATION: RNA PROTEIN
OCCURS
-In the cytoplasm on free ribosomes
-mRNA directs the RNA to the ribosome where tRNA translates (decodes) the codon
(sequence of three bases) to a specific amino acid.
-Then the amino acids combine to make a specific protein (polypeptide).
ENZYMES REQUIRED
amina-acyl tRNA synthetase – binds the amino acid to specific tRNA

29.

DNA DNA
DNA mRNA
mRNA amino acid
Mitosis / Meiosis
RNA
_________________________________________________________
mRNA – messenger RNA(codon) takes message of DNA, edits it, then takes it
through the nuclear pores to the cytoplasm.
rRNA – ribosomal RNA – RNA that assists with protein synthesis. Found in
cytoplasm and on rough ER.
tRNA – transferRNA(anticodon) – RNA that transfers a specific amino acid to
the ribosomes for protein synthesis

30. RNA

Major Differences DNA RNA https://www.youtube.com/watch?v=6L3zO8t1lsE
Professor Dave DNA RNA (7.0) https://www.youtube.com/watch?v=6NhDY3IDp00
Differences in DNA RNA (2.40) https://www.youtube.com/watch?v=ruUf7ntRCk8

31.

32.

33.

34. Compare DNA to RNA

35.

Complete the chart by reading each term or phrase and placing a check in the appropriate column.
DNA
Deoxyribose
single stranded
nucleotides
found in nucleus only
Both
Ribose
double stranded
RNA
found in and out of nucleus
Cytosine
Guanine
Adenine
Thymine
Uracil
double helix
replication

36. Compare DNA to RNA

DNA
Characteristic
Number of strands
mass
Location in cell
sugar
Nitrogen bases
Ratio of purines to
pyrimidines
Types or forms
Chemical stability
RNA

37.

38. Quiz Formative

39.

40.

41.

42.

43.

44. DNA Structure Review

1. In your notebook, place the template under the page
and trace.
2. Next, use the template to find the completementary
strand.
3. Why is DNA said to be “antiparallel”?
4. Circle a nucleotide
_
5. Label hydrogen bonds G=C , A=T see diagram.
6. Number the carbons of a sugar.
RNA Nucleotide
7. Label a phosphodiester bond.
Sugar
Deoxyribose
GCAT
DNA Nucleotide
Sugar
Ribose
GCAU

45.

Antiparallel
Phosphodiester
Bonds
Nucleotide

46. Nitrogenous Bases

GCAT – meow!
Purines
Adenine
DNA: G-C A-T
mRNA: C-G U-A
Guanine
Pyrimidines
Thymine
Cytosine
Uracil

47. DNA Replication

48. Three types of RNA