the storehouse of information that governs heritable traits. Its found on the nucleus of eukaryotic cells.

a double stranded molecule consisting of four kinds of nucleotides: adenine, thymine, guanine, and cytosine.

Its strands are in opposite directions; the strands are complimentary not exact.

the two strands coil together helically, like a spiral stairway.

discovered the dna double helix;

the apperance of dna in all cells;

resposnible for these two ensights:

the amount of adenine and guanine differs amoung species.

The amounts of thymine and adenine in DNA are identical and so are the amounts of cytosine and guanine. A=t and G=C.

X-Ray diffraction images

made by Rosalind Franklin (first to put DNA in a "wet" form);

a beam of x-rays is directed at a molecule, which scatters the x-rays in a pattern that can be captured on film.

Storage of info

replication - dna makes exact compies of itself

mutation - change in DNA sequence

transformation - DNA moves from one cell to the next in bacteria cell.

simple building units of nucleic acid;

composed of three parts:

sugar:deoxiribose

Phosphate group

Nitrogen base

Two types of nitrogen bases

purines:adenine and guanine

pyrimidines: cytosine and thymine

discovered the semi-conservative replication of DNA;

each DNA molecule is comosed of an old and new strand;

DNA makes an exact copy of itself;

replicatiion will always occur before cell reproduction;

replcation occurs in the nucleus of eukaryotic cells (which is where DNA is located).

First enzymes present in replication;

unravel DNA double helix;

2nd enzymes present in replication;

add free complimentary nucleotides to each DNA strand;

monomers of DNA

last enzyme of replication;

seals dna fragments;

recognize and snip out a damage site or mismatches;