chapter 17 - nucleic acids

nucleic acids def

large molecules found in the nucleus that store info + direct cellular activity

what does DNA stand for?

deoxyribonucleic acid

what does RNA stand for?

ribonucleic acid

what is the role of DNA?

stores genetic information

what is the role of RNA?

translates/interprets genetic info in DNA for protein synthesis

what does a nucleotide consist of

does DNA or RNA have more nucleotides?

DNA has more

• DNA has several million

• RNA has several thousand

in a nucleotide, how many members does the monosaccharide have?

• 5-membered ring

• pentose

how does the monosaccharide in a DNA different from an RNA?

• RNA has an OH on carbon 2

• DNA has only an H on carbon 2 (deoxy)

what are the types of major bases in DNA and RNA?

• purine

• pyrimidine

characteristics of purine

• 2 rings

• 2 bases

  • adenine (A) and guanine (G)

characteristics of pyrimidine

• 1 ring

• 3 bases

  • cytosine (C), uracil (U), and thymine (T)

what bases does DNA have?

A, G, C, T

what bases does RNA have?

A, G, C, U

nucleosides def

joins a monosaccharide and a base (purine/pyrimidine)

nucleoside description

connects the c1 of the monosaccharide to a N atom of the base

nucleotide def

joins a nucleoside with a phosphate

nucleotide description

phosphate group gets connected to the carbon 5 of the nucleoside

in what order are nucleotides ordered?

from the 5’ to 3’

what are the different structure types of polynucleotides?

• primary

• secondary

• tertiary

primary structure of a protein def

• the sequence of nucleotide residues

• named by one letter abbreviations

  • example: d in dAMP shows that its DNA

gene def

a section of DNA that codes for protein production

what is the linkage between a phosphate and the next saccharide called in a polynucleotide?

phosphodiester linkage

what type of bonds hold together bases in sgar/phosphates?

hydrogen bonds

what is created when a DNA gets coiled around a protein?

nucleosome chain

what enzyme helps break the hydrogen bonds in DNA for the process of replication?

helicase

what does helicase do?

breaks hydrogen bonds that hold DNA together

what is exposed when helicase helps unwind DNA?

• the origin

origin def

• a specific area on DNA where replication process begins and the bases are exposed

where does replication take place?

the replication fork

SSB definition

• stands for single strand binding proteins

SSBs function

keeps the unwinded DNA apart after it is unwinded by blocking hydrogen bonding

polymerase function

attaches itself to the strands of DNA during replication to catalyze the reaction

what are the different types of RNA?

• ribosomal RNA (rRNA)

• messenger RNA (mRNA)

• transfer RNA (tRNA)

ribosomal RNA def

• combines with proteins to make ribosomes

• location where protein synthesis takes place

messenger RNA def

carries info from DNA to the ribosome

transfer RNA def

brings specific amino acids to the ribosomes for protein synthesis

which type of RNA is the longest?

rRNA

which type of RNA is the shortest?

tRNA

what is the first step in making proteins?

transciption

promoter site def

spot on DNA where the polymerase attaches to start transcription

what is read by the polymerase on DNA?

the template strand

what are the three digits used for, mRNA, tRNA, or rRNA

mRNA

what is the triplet code called for mRNA?

codon

where are anticodons found, mRNA, tRNA, or rRNA

tRNA

anticodon description

a bind to a codon on mRNA

• U to A, G to C, T to A…

what is another term for translation?

protein synthesis

what are the steps of translation?

• initiation

• elongation

• termination

where does translation occur?

in the ribosome