DNA/RNA

DNA/RNA

DNA RNA

Watson & Crick

Maurice Wilkins & Rosalind Franklin

Rosalind Franklin

Chargaff’s Rule of RatiosFrom analytic studies Edwin Chargaff

(1952) determined that the:

Amount of Adenine always equals the amount of Thymine

Amount of Cytosine always equals the amount of Guanine

The amount of A-T is independent of the amount of C-G

Erwin Chargaff, an American biochemist

DNA: replication and protein synthesis

Where have we seen DNA being replicated?

MITOSIS AND MEIOSIS

Building blocks of DNA: Nucleotides

The sugar

The phosphate Deoxyribo

se

The nitrogenous bases

The Purines

Why are these called nitrogenous bases?

The nitrogenous bases

The Pyrimidines

How are the pyrimidines different from the purines?

Four different NucleotidesBASIC

STRUCTURE

DNA is a polymer formed by base pairing: Base pairing rule

The Double HelixA.The overall shape of DNA is described as a

double helix (a twisted ladder).B.What force holds the two strands together?

Purines Pyrimidines

Adenine Guanine Cytosine Thymine

Phosphate group Deoxyribose

 DNA NucleotidesSection 12-1

DNA Replication

ANIMATION ANIMATION DETAILED

Enzymes involved in DNA replication

Helicase – opens the double helix to allow for replication

DNA polymerase – reads the original DNA strand and lays down complementary bases

Ligase – glues the newly formed DNA together

DNA replication practice You are DNA polymerase. Helicase has opened the

DNA strand – read each side and produce the complementary copies.

__________________________________A G G T A A C C G G T T A C G A T T A TT C C A T T G G C C A A T G C T A A T A

A G G T A A C C G G T T A C G A T T A TT C C A T T G G C C A A T G C T A A T A

12.2 (part 2) - The Structure of DNA

Solving the Structure of DNA Three scientists who worked to solve the structure of DNA were

Rosalind Franklin, James Watson, and Francis Crick. Franklin found clues. These clues helped Watson and Crick explain the structure and properties of DNA.

12.2 (part 2) - The Structure of DNA

A Venn diagram is made up of overlapping circles. It is a useful tool for comparing two or even three topics. In the space where the circles overlap, write the features that the topics share. In the space where the circles do not overlap, write the features that are unique to each topic.

built a three-dimensional model of DNA helped determine the shape of a DNA molecule photographed DNA using X-ray diffraction showed that DNA is a double helix studied DNA’s structure and properties

12.2 (part 2) - The Structure of DNA Complete the Venn diagram using phrases

from the word box.

photographed DNA using X-ray diffraction

- studied DNA’s structure and properties

helped determine the shape of a DNA molecule

showed that DNA is a double helix

built a three-dimensional model of DNA

How are DNA and RNA similar?

DNA is composed of nucleotides and RNA is composed of nucleotides

IN YOUR NOTES TO PRACTICE BASE PAIRING RULES AGAIN__________________________________A G T C C G T T A G T

T C A G G C A A T C A

Let’s Review

DNA Structure is a _____ ______ DNA is composed of __________

What are four that make up DNA? A T C G

How are DNA and RNA different? DNA…

Nucleotides = deoxyribose sugar Double helix structure Stays inside nucleus

RNA… Nuleotides = ribose sugar Single-strand structure Located both inside and outside of nucleus Uracil instead of thymine

How are DNA and RNA different?

Transcription

mRNA – stands for messenger RNA it is the copy of the DNA message for making

a protein Occurs in the nucleus Promoter region on DNA marks where

transcription should start and terminator region marks where it should stop

mRNA

Transcribes DNA message and carries it to ribosome

RNA polymerse is the enzyme that produces it

CLICK ON PICTURE FOR ANIMATION ON TRANSCRIPTION

mRNA

No T (thymine) so when it reads the nucleotide A on DNA it matches it with ____?

Protein Synthesis= transcription and translation DNA contains all the information for your

traits – the genes These genes are blueprints and need to

remain safe – kept inside the nucleus Copies can be made though – a messenger

Genotype Phenotype

DNA mRNA tRNA PROTEIN

Transcription Translation

tRNA

Once mRNA is made it attaches to a ribosome

tRNA = transfer RNA and they carry amino acids

Amino acids are the building blocks of proteins (remember?)

Translation

Ribosomes are the site of protein synthesis Click here to see mRNA and tRNA work toget

her at that ribosome to build a protein

Codon = mRNAAnti-codon = tRNA

Comparing RNA & DNA

DNA RNA

Nucleotide

Deoxyribose

Ribose

Single-stranded

Double-stranded

Nitrogenous bases

X

X

X

X

X

X

X X

Comparing RNA & DNA

DNA RNA

Thymine

Uracil

Template for synthesis of nucleic acidDouble helix

Replication

Transcription

X

X

X

X

X

X X

Comparing RNA & DNADNA RNA

Exact Copy

Messenger

More Than 1 FormFound in NucleusLeaves Nucleus

Does not Leave

X

X

XX

X

X

X

Hydrogen bonds

Nucleotide

Sugar-phosphate backbone

KeyAdenine (A)

Thymine (T)

Cytosine (C)

Guanine (G)

Figure 12–7 Structure of DNASection 12-1

RNADNA

RNApolymerase

Figure 12–14 TranscriptionSection 12-3

Adenine (DNA and RNA)Cystosine (DNA and RNA)Guanine(DNA and RNA)Thymine (DNA only)Uracil (RNA only)

from to to make up

Do Now Begin - RNA Concept Map

also called which functions to also called also called which functions towhich functions to

can be

from to to make up

RNA Concept Map

also called which functions to also called also called which functions towhich functions to

can be

RNA

mRNA rRNA tRNA

Messenger RNA

Carry instructions Ribosomal RNA

Combine withprotein Transfer RNA Brings amino acids

to the ribosome

Ribosomes RibosomesDNA

Deletion

Duplication

Inversion

Translocation

 Chromosomal Mutations