Chapter 12

• Store information
• be stable enough to be replicated
• undergo rare changes mutations

Nucliotides

• 5 carbon sugar-deoxyribose
• phosphate group 
• N-containing base-Adenine Guanine Cytosine thymine

• Amount of A,T,C, and G varies between species
• the amount of adenine equals the amout of thymine and the amount of guanine equals the amount of cytosine
• 50% of bases are purines and 50% are pyrimidines

A and G- 2 carbon rings

C and T- 1 carbon ring

2 strands composed of a sugar and phosphate backbone with N-containing bases paired on the inside-2 strands spiral or twist around each other

thymine

Cytosine

During replication each old strand of the parent molecule serves as a template for a new strand in a daughter molecule

• unwinding-the weak hydrogen bonds are broken
• complementary base pairing- A pairs with T and C pairs with G
• joining-nuckeotides join to form a new strand

because each daughter molecule has one old strand and one new strand

each gene contains the info for making one protien

Ribonucleic Acid

Deoxyribose Nucleic Acid

• different sugar-ribose
• different base-uracil replaces thymine
• different number of strands-1 single straight strand

takes a message fromt he DNA in the nucleus to the ribosomes in the cytoplasm

along with protiens, makes up the ribosomes

carries amino acids to the robosomes

the process by which a gene produces a product usually a protien

a sequence of nucleotide bases that codes for a product usually a protien

occurs in the nucleus. process of making mRNA copy from DNA. similar to DNA replication bc one strand of DNA serves as the template for the mRNA formation

occurs in the cytoplasm. process by which the sequence of nucleotide bases in mRNA determines the sequence of the amino acids in a protein

consists of 64 three base "words" called codons.

3 nucleoitides of mRNA that code for a specific amino acid or the start/stop of translation

• 1.DNA in nucleus serves as template for its own replication and for mRNA during transcription
• 2.mRNA is processed before leaving nucleus and the introns(portions dont leave nucleus) are removed
• 3.When mRNA is formed it has codons
• 4.mRNA moves to cytoplasm and becomes assoiciated with ribosomes
• 5.tRNA with anti codons carries amino acids to mRNA and ribosome
• 6.anticodon-codon complimentary base pairing occurs
• 7.peptide cahin is transferred from resident tRNA to new tRNA
• 8.tRNA departs and will soon pick up another amino acid
• 9.continues till reach a stop codon than releases a protien

a string of robosomes simultaneously reading different regions of the smae mRNA strand

perm. change in the DNA either chromosome or gene

a change in the nucleotide sequence

a nucleotide is inserted or deleted

a change in a single nucleotide base

enviromental substances that cause mutations