DNA Structure & Replication PPT Flashcards
chemical compound that passes hereditary information from generation to generation
deoxyribonucleic acid (DNA)
What are the building blocks of DNA?
DNA is composed of a long chain of nucleotides.
Each nucleotide in DNA has ___ components and are attached with ___ bonds.
3,
covalent
How many different nucleotides make up DNA?
4
2 ring nitrogen base structure
purines
1 ring nitrogen base structure
pyrimidines
Which nucleotides have a purine base?
adenine,
guanine
Which nucleotides have a pyrimidine base?
thymine,
cytosine
Who discovered how the nucleotides are assembled and when?
Erwin Chargaff (1949)
How are the nucleotides assembled?
purines attach to pyrimidines (A=T and G=C)
Whose x-ray diffraction images suggested DNA structure?
Rosalind Franklin
Describe DNA structure.
- long and thin
- uniform diameter
- two varying repeats suggests a double coil/helix
determined the double helix structure of DNA and built a model to display it; won a Nobel prize
Watson and Crick (1953)
a twisted ladder structure; sugar-phosphate are the sides that make up a “backbone”; nitrogen bases attach across as the rungs (A=T and G=C); two strands run antiparallel and are complimentary to each other (3 prime to 5 prime)
double helix structure
Nitrogen bases in DNA attach with ___ bonds.
hydrogen