Halloran Honors Bio - 10 Ch7 DNA Discovery and Structure

Frederick Griffith

established the idea of a "transforming agent" capable of being transferred and changing organism's traits; not sure if agent was protein or DNA; used Streptococcus pneumoniae and mice

Oswald Avery

experiment concluded DNA (not protein) is the genetic material (transforming agent); used Streptococcus pneumoniae in culture

Alfred Hershey & Martha Chase

experiment concluded DNA (not protein) is the genetic material (transforming agent); used radioactively tagged bacteriophages

bacteriophage

virus that infects bacteria

James Watson & Francis Crick

devised the double helix model of DNA

Erwin Chargaff

Chargaff's Rules (amount of A \= amount of T and amount of G \= amount of C)

Rosalind Franklin & Maurice Wilkins

X-ray diffraction photos revealed the double helix structure of the DNA molecule

nucleic acids

biomolecule - CHOPN; subunits - nucleotides; include DNA and RNA

nucleotide

subunit of nucleic acids; composed of a pentose sugar, nitrogenous base, and phosphate group

ribonucleotide

subunit of RNA; nucleotide composed with the pentose sugar ribose

deoxyribonucleic acid

DNA; information storage molecule in the cells of living organisms; contains the code on how to construct proteins

ribonucleic acid

RNA; information molecule that relays genetic code from the nucleus of the cell to the ribosomes in the cytosol

pentose sugar

5 carbon sugar

deoxyribose

5 carbon sugar used in the nucleotides of DNA; has a H bonded off of the 2' carbon

ribose

5 carbon sugar used in the ribonucleotides of RNA; has a OH bonded off of the 2' carbon

nitrogenous base

the bases that form the code of nucleic acids; AGCTU, bonded off the 1' carbon of a nucleotide, single or double ring shaped molecule with C and N in ring

adenine

purine; complementary bonds with thymine or uracil

guanine

purine; complementary bonds with cytosine

cytosine

pyrimidine; complementary bonds with guanine

thymine

pyrimidine in DNA; complementary bonds with adenine

uracil

pyrimidine in RNA; complementary bonds with adenine

purine

double-ringed nitrogenous base; adenine and guanine

pyrimidine

single-ringed nitrogenous base; cytosine, thymine, and uracil

1' - 5' carbons

label the carbons in a pentose sugar clockwise in numerical order starting to the right of the O in the ring

double helix

the structural shape of a molecule of DNA

double stranded

DNA - contains two chains of nucleotides kept together by the hydrogen bonds between the complementary bases

single stranded

RNA - contains one chain of ribonucleotides (only one side of the ladder)

complementary base pairing

hydrogen bonding between matching nitrogenous bases; A - T and C - G

antiparallel

the opposite orientation of the two strands of nucleotides in a molecule of DNA

C-G

joined by 3 hydrogen bonds

A-T

joined by 2 hydrogen bonds

3' end

only place where new nucleotides can be joined to a growing nucleic acid strand

hydrogen bonds

join the nitrogenous bases in double stranded DNA

phosphodiester bonds

the covalent bonds that join nucleotides and create the backbone; link the sugar to the phosphate of the next nucleotide in the strand

major groove

the larger of the two grooves in a DNA double helix; provides a location where a protein or enzyme can bind to a particular sequence of bases

minor groove

the smaller of the two grooves in a DNA double helix