CHAPTER 12

able to store information that pertains to the development, structure, and metabolic activities of the cell or organism stable, so it can be replicated with high accuracy during cell division and be transmitted from generation to generation able to undergo rare changes, called mutations, that provide the genetic variability required for evolution to occur

2 purine bases, adenine and guanine, which have a double ring 2 pyrimidine bases, thymine and cytosine, which have a single ring

the amount of a, t, g, and c in dna varies from species to species in each species, the amount of a = t and the amount of g = c

dna is a double helix with sugar-phosphate backbones on the outside and paired bases on the inside

means that a purine is always bonded to a pyrimidine

dna must always be read in the 5’ to 3’ direction, thus is usually replicated in this direction

refers to the process of copying a dna molecule

each daughter dna double helix contains an old strand from the parental dna double helix and new strand

a pairs with t and g pairs with c

separates double stranded dna into single strands

synthesizes short rna primers

synthesizes dna in the leading and lagging strands; removes rna primers, filling the gaps with more dna; and proofreads newly made dna

binds to single stranded dna and prevents it from reforming a double helix

the place where replication begins, a specific site on the bacterial chromosome

covalently attaches adjacent okazaki fragments in the lagging strand

where replication stops

there is a v shape wherever dna is being replicated, this is called the replication fork

a polymer composed of nucleotides. the nucleotides in rna, however, contain the sugar ribose and the bases adenine, cytosine, guanine and uracil

the flow of dna to rna and then on an expressed protein

takes a message from the dna in the nucleus to the ribosomes in the cytoplasm

transfers amino acids to the ribosomes

along with ribosomal proteins, makes up the ribosomes, where polypeptides are synthesized

a process by which an rna molecule is produced based on a dna template.

the mrna transcript is read by a ribosome and converted into the sequence of amino acids in a polypeptide