Bio 2 Chapter 14 Flashcards

Gene

a segment of DNA that give your body the instructions for a specific characteristic

Friedrich Miescher

isolated phosphate rich acidic compounds to discover DNA

Bacteriophage

a virus that effects bacteria cells

35S

labels protein

32P

labels DNA

DNA

deoxyribose; double-stranded

RNA

ribose; single-stranded

Pyrimidines

single-ring structures

Purines

double-ring structures

Erwin Chargaff

discovered a relationship between nucleotides

Sugar phosphate backbone

the structure of DNA’ s “ladder”

Hydrogen bonds

also known as complementary base pairing; holds the nucleotides together

Phosphodiester

a chemical bond that forms the sugar phosphate backbone

Antiparallel

the two polymer strands run in opposite directions

Semi-conservative replication

the two strands come apart and each strand acts as a template for synthesis of a new strand

Conservative replication

original parent double strands remain intact and two completely new double helix strands are synthesized

Dispersive replication

both original parent strands are broken up into small pieces and incorporated into newly synthesized strands

Meselson and Stahl

experimented with E. coli grown first in heavy nitrogen (15N) then in 14N

Replication fork

formed when helicase separates the DNA strands at the origin of replication

Topoisomerase

prevents the over-winding of the DNA double helix ahead of the replication fork as the DNA is opening up

Single-strand binding proteins (ssb)

bind to the single-stranded DNA to prevent the helix from re-forming

Primase

synthesizes an RNA primer

DNA polymerases

use this primer to synthesize the daughter DNA strand and replace the RNA primer with DNA

DNA ligase

seals the gaps between the Okazaki fragments, joining the fragments into a single DNA molecule

Eukaryote

contains a well-defined nucleus

Prokaryotes

the chromosome lies in the cytoplasm in an area called the nucleoid