68
The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA

The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

  • Upload
    vobao

  • View
    225

  • Download
    0

Embed Size (px)

Citation preview

Page 1: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

The Structure & Function of Deoxyribose Nucleic Acid

Crash Course in

The Why’s & How’s

of

DNA

Page 2: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Fredrick Griffith 1928

Page 3: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Frederick Griffith

Page 4: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Oswald Avery 1944

Page 5: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Hershey & Chase 1952

Page 6: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Hershey & Chase

Page 7: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

The Race

Page 8: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

WATSON and CRICK

• Announced in 1953

• Used the results of other scientists to figure out the structure of DNA

Page 9: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Erwin Chargaff

Page 10: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

The Work of Biochemists

Page 11: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 12: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Watson & Crick Model• Chemists found that DNA polymerized through the

formation of phosphodiester linkages– This concluded a sugar-phosphate backbone

• By analyzing the total number of purines and pyrimidines it was found that the number of A’s and T’s were equal to the number of C’s and G’s– This was called Chargaff’s rule after Erwin Chargaff

• X-ray diffraction showed a repeating scatter pattern (.34 nm, 2.0nm, 3.4nm)– This repeating pattern only makes sense if the molecule is

shaped as a double helix

Page 13: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Scatter Pattern X-ray Diffraction

Page 14: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Scatter Pattern X-ray Diffraction

• Watson & Crick began to analyze the size and geometry of deoxyribose, phosphate groups, and nitrogenous bases.

• Using things like bond angles, and measurements, they were able to devise 2.0nm probably represented the width of the helix, and .34 was likely the distance between bases stacked in the spiral

• They arranged two strands of DNA running in opposite directions (5`-3` and 3`-5`)

Page 15: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

And the Winner IS…

Page 16: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

DNA Size

• Width of the helix = 2.0nm

• Length of one full complete turn of helix = 3.4nm

• Distance between bases = .34nm

• Antiparallel Double Helix

– 3’ 5’ & 5’ 3’

Page 17: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

The Roof of the Sugar Molecule

C=O

It is

po

inti

ng

at t

he

5’ e

nd

!

Page 18: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Count Your Primes

Page 19: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Base Pairing

• Using the x-ray diffraction patterns and measurements, it was found only to work if:

• Adenine always bonded with Thymine

• Guanine always bonded with Cytosine

• This phenomena is called Complimentary Base Pairing

Page 20: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

DNA REPLICATION• Occurs during S-phase of the cell cycle

• DNA has a special “complimentary structure”that acts as a template for reproduction– This means, it allows for simple DNA copying

• The strand unzips, and the old strand acts for a model to create a new “compliment”

• The strand copies in two directions:– The Leading strand starts at the 3’ end and moves towards

the 5’ end

– The Lagging strand pieces together new nucleotides starting at the replication fork and works toward the 5’

Page 21: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 22: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Prokaryotic Replication Proteins• Helicase: Unwinds parental double helix at replication

fork• Single Strand Binding Protein: Binds to and stabilizes

DNA strand after it has separated• Topoisomerase: Relieves the “overwinding” strain that

can occur ahead of the replication fork (swivel motion)• Primase: Synthesizes an RNA primer at the 5’ end of

replicating strand.• DNA pol III: Using the template strand, covalently bonds

nucleotides to the 3’ end of the pre-existing RNA strand or primer

• DNA pol 1: Removes RNA primers & replaces them with DNA nucleotides

• DNA Ligase: Joins 3’ end of DNA that replaces primer to the rest of strand (Joins Okazaki fragments of lagging strand)

Page 23: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 24: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 25: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

DNA Excision Repair• Nucleotide excision repair (NER) is a particularly

important excision mechanism that removes DNA damage induced by ultraviolet light (UV).

• Recognition of the damage leads to removal of a short single-stranded DNA segment that contains the lesion (By the Nuclease enzyme).

• The undamaged single-stranded DNA remains and DNA polymerase uses it as a template to synthesize a short complementary sequence.

• Final ligation to complete NER and form a double stranded DNA is carried out by DNA ligase.

Page 26: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 27: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 28: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

How Does a Cell Make Proteins?• The RNA molecule comes out of the nuclear

envelope after it is transcribed from DNA (Its like a photocopy)– Transcription is the process of creating an RNA

strand from a template of DNA nucleotides

• The process of protein synthesis is called translation– Translation refers to the process of converting the

“3-nucleotide RNA codons” into amino acids and then into amino acid chains

Page 29: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 30: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 31: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 32: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

RNA & Protein Synthesis

• RNA has very specific blue prints that it uses to build the various amino acids (proteins) called Codons.

• These codons allow for the difficult job of the synthesis of the many proteins to be grouped into simple readable prints (codons) including “stop and start” codons

Page 33: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

The Genetic Code

• It is almost as if a cell is “pre-programmed” with a guide for making life

• If there was such a “program” it would need to be something contained in nearly EVERY cell, so that each cell could individually work at it

• We call this program “the Genetic Code”

• It is the control for life as we know it

Page 35: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Translation Elongation

Codon recognition

accuracy

Peptide bond formation

P site AA is attached to AA chain

Translocation: mRNA slides

through (P to E and released)

GTP required for movement

Page 36: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Translation TerminationProtein shaped

like tRNA

R factor hydrolyzes

bond between tRNA and

last AA

2 GTP molecules

are required to break

translation assembly

Page 37: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Sweet Moving Slide

Page 38: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Genetic Engineering Techniques

• Restriction Enzymes

• DNA Recombination

• DNA Insertion

• DNA Sequencing

• Transgenic Bacteria, Plants, and Animals

• Cloning

• Gel electrophoresis

• DNA Polymerase Chain Reaction (PCR)

Page 39: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Genetic Engineering Techniques

• Restriction Enzymes:– Genes can be cut at specific DNA sequences by proteins

known as Restriction Enzymes

• (We know over 3,000 different restriction enzymes)– Each recognizes and cuts DNA at a particular sequence

(area of Bases)

• They are INCREDIBLY accurate, they will ONLY cut the area that they recognize

• This amazing ability allows us to cut DNA into fragments so that we can isolate it, separate it, and/or analyze it.

Page 40: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 41: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Genetic Engineering Techniques

• DNA RECOMBINANTS:

– DNA fragments (cut by restriction enzymes) may be combined with bacterial DNA so that they can later be inserted into a bacterial cell

– The small, circular DNA molecules in bacteria (called plasmids) can be removed and cut with a restriction enzyme.

– The cut ends are sticky to the foreign fragment, and can allow for the formation of a recombinant DNA molecule

Page 42: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 43: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Genetic Engineering Techniques• DNA INSERTION:

– During the first 2 steps of genetic engineering, DNA fragments containing the desired gene are obtained and then inserted into DNA that has been removed from the recipient cell (the cell where the DNA is going.)• Forming recombinant DNA (New DNA)

– To insert the DNA into LIVING cells it is easiest to use bacteria• Bacteria in a solution of salt and the desired DNA will eventually

take up the DNA in its own DNA.

• These new bacteria are then cultured (grown) into a large colony.

• The technical term for a large number of cells grown from a single cells Clone. So this is DNA cloning.

• You don’t HAVE to use bacteria but it is the easiest.

Page 44: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 45: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 46: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Genetic Engineering Techniques

• DNA sequencing:

– Sequencing DNA is when you read the nitrogenous bases (ATCG) along the length of the DNA fragment.

– Only one strand of the double helix is used to sequence the DNA, but they do need multiples of the used strand (So you clone it)

– The DNA is divided to 4 groups that undergo different chemical treatments that break the pieces and reveal the Base sequence.

– The pieces are separated by electrophoresis.

Page 47: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 48: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Gel electrophoresis

• During gel electrophoresis, DNA is cut with a restriction enzyme into small pieces

• Because DNA has a slight negative charge, different charges are placed at either end of a gel containing tray.

• When the DNA is placed into the tray it will slowly move across the gel (towards the +)

• Because the pieces are different sizes they move at different speeds.

Page 49: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

DNA Fingerprinting

• The amazing complexity of the human genome ensures that NO TWO INDIVIDUALSare exactly the same.

• This biological “fact” (or more likely theory) allows for a powerful new tool in criminal investigations

• Now, finding bodily fluids and/or skin cells at the scene of a crime or on a victim can link a suspect to a crime with amazing reliability.

Page 50: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Electrophoresis

Page 51: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Electrophoresis

Page 52: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

PCR

• Polymerase Chain Reaction (PCR) is a technique used to copy DNA

– Original DNA strand (with desired gene) is heated to separate strands

– AS it cools, primers are added to the solution

– DNA polymerase utilizes free nucleotides to copy the template strands

– The procedure can be repeated as many times as needed.

Page 53: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 54: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Genetic Engineering Techniques

• Transgenic

– It is now possible to insert genes from one organism into another.

– Organisms that contain such foreign genes are said to be Transgenic.

– Trans- across or moved genes

Page 55: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Transgenic Organisms• Transgenic Bacteria:

– When a gene coding for a human protein (like a hormone or enzyme) is inserted into bacteria, the new recombinant cells may produce LARGE amounts of the protein.

– The human growth hormone, a hormone required for growth and development, was incredibly rare before genetic engineering.

– Now these transgenic bacteria (with the corresponding foreign gene) are able to produce enough growth hormone so that everyone who needs it has all they need.

– Other proteins, like insulin (used in the treatment of diabetes) and interferon (used to block viral growth and battle cancer) are also made by transgenic protein

Page 56: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Transgenic Organisms

• Transgenic Animals:– DNA can be introduced into animal cells many

ways, including direct injection

– Growth hormones are used daily in many of the cattle, fish, and poultry that we eat.

– We also use genetic engineering (DNA Fragment Injection) to gain strains of AIDS that we use to investigate the cure, further research into the human immune system, and many other medical researches.

Page 57: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Green Fluorescent Protein (GFP)

Page 58: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

This transgenic animal is the result of placing jellyfish genes in an albino rabbit,

and then bathing it in UV light

Page 59: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Transgenic Organisms

Page 60: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Transgenic Plants

• It is through the process of genetic engineering that we have most of the plants that we use for food.

• Not only can we selectively breed more productive organisms, but we can use transgenic organisms to make plants that are resistant to diseases, insects, drought, winds, etc.

Page 61: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 62: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

CLONING

• In 1997 a Scottish scientist (Ian Wilmut) cloned a sheep in which he named Dolly… since this time we have cloned a multitude of organisms (not including humans)

• To do this, the nucleus within an egg is removed and replaced with the nucleus of an adult cell.

• The cell is then placed into the reproductive system a foster mother.

Page 63: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Making Dolly

Page 64: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Dolly’s life was cut short by cancer only a few years following her creation…

Page 65: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick
Page 66: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Cloning

Page 67: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick

Human Genome

• Despite what many (older) books may say we HAVE actually mapped the ENTIRE human genome.

• This was something that was originally considered impossible, but as of 2003, every transcribing base in the human DNA strand is mapped, and at least to a degree, understood

• We know the “loci” (location) of every protein producing gene in the human body

Page 68: The Structure & Function of Deoxyribose Nucleic Acid 16...The Structure & Function of Deoxyribose Nucleic Acid Crash Course in The Why’s & How’s of DNA Fredrick Griffith 1928 Frederick