A
What does DNA stand for?
deoxyribonucleic acid
What are the four nitrogenous bases?
Adenine (A), thymine (T), cytosine (C), guanine (G)
The oxygen of deoxyribose always points in __ to __ direction?
3' to 5'
When was DNA discovered?
1869
replication
how many chromosomes does every body cell or somatic cell have?
46
What is the shape of a DNA molecule?
Double helix - like a twisted ladder
A-T and C-G
Who discovered DNA?
Friedrich Miescher
What enzyme "unzips the gene" ?
helicase
These chromosomes are packed together tightly with ________ in the nucleus of the cells.
Proteins
DNA molecules are ________, made up of small, repeating molecular units called ________.
Polymers, Nucleotides
Which base pair is slightly stronger?
G-C
Who used a technique called x-ray diffraction to confirm the helical structure and place the sugar-phosphate backbones on the outside?
Rosalind Franklin
The replication fork
DNA and RNA are __________, a major group of macromolecules
Nucleic Acids
How do the sugar-phosophate backbones appear in relation to the other?
Upside-down; they are chemically in opposite directions. (anti-parallel)
With all 46 DNA molecules together, there are roughly _________ base pairs in every cell.
6 Billion
These two people published the first complete description of the DNA structure and were awarded a Nobel Prize in 1962
Watson and Crick
DNA polymerase
What are three things that make up a nucleotide?
a. a five carbon sugar molecule
b. a phoshate group
c. one of four nitrogenous bases
The two chains of DNA are held together at the bases by weak ________ bonds.
hydrogen
Name three differences between DNA and RNA
a. RNA is a single-stranded molecule
b. The sugar in RNA is ribose which has one more oxygen atom than deoxyribose
c. Contains the base uracil instead of thymine, so U bonds with A
The ________ strand of DNA only needs the primer once.
leading
RNA primase