Unit 7 - DNA Replication

chromatin

genetic material and histones in long strands

chromosomes

form of genetic material during and right before cell division

histones

proteins that wrap DNA in long strands

nitrogen base

a molecule that contains nitrogen and has the chemical properties of a base

• adenine

• guanine

• thymine

• cytosine

DNA mutation

mutation causing agent

sugar phosphate backbone

• forms the structural framework of nucleic acids

• linked with covalent bonds

semi-conservative DNA replication

each copy of the DNA conserves the information from one half of the original molecule

Okazaki fragments

short sections of DNA formed at the time of discontinuous synthesis of the lagging strand during replication of DNA

circular DNA

closed loop DNA that has no ends

• found in the cytoplasm of most prokaryotic cells

nucleotides

• monomer

• made of phosphate, deoxyribose sugar, and nitrogen base

double helix

the physical structure of DNA

helicase

unzips hydrogen-bonds

adenine

• purine (2)

• pairs with thymine

cytosine

• pyrimidine (1)

• pairs with guanine

deoxyribose

sugar

DNA polymerase

building/proof reading

replication fork

the area where DNA replication occurs

template strand

DNA strand that is duplicated

purine

• double ringed

• adenine and guanine

primase     

priming during DNA replication

thymine

• pyrimidine (1)

• pairs with adenine

guanine

• purine (2)

• pairs with cytosine

daughter strand

the copied strand

base pairing

two nitrogen containing bases (nucleotides) that pair to form DNA

• adenine and thymine

• cytosine and guanine

DNA ligase

glue for a lagging strand

pyrimidine

• single ringed

• thymine and cytosine

genotype

the genes you have

Hershey & Chase

• used radioactive isotopes to find that DNA was the genetic material of bacteriophages

• radioactivity was detected outside the infected bacteria for radioactive protein experiment but inside the infected bacteria for the radioactive DNA experiment

Rosalin Franklin

provided X-ray evidence that DNA was a helical shape and was used to determine dimensions

Watson & Crick

• determined structure of DNA

• 2 nanometers wide, helix shape

Chargaff’s Rule

DNA from any cell will have a 1:1 pairing of pyrimidine to purine bases