ap biology | gene expression + regulation

what organisms use rna as their primary genetic material?

viruses

dna is __ stable than rna

more

what makes dna more stable than rna?

deoxyribose has a hydrogen atom while ribose has a hydroxyl group

semiconservative

the way dna replicates

each new double helix is composed of one strand for the original dna and one newly synthesized strand

helicase

an enzyme that unwinds the two dna strands in the origin of replication

topoisomerase

enzymes that relieve supercoiling

rna polymerase

enzyme that synthesizes an rna primer using a few complementary rna nucleotides

dna polymerase

enzyme that adds new nucleotides in the 5’ to 3’ direction

dna polymerase reads in a ____ direction

3’ to 5’ direction

lagging strand

the strand oriented in the 5’ to 3’ direction

replication on this strand occurs discontinuously

okazaki fragments

the result of replication on the lagging strand, producing short fragments

ligase

an enzyme that joins okazaki fragments together

central dogma

the flow of genetic information in a cell

dna→mrna→ribosomes

transcription

the process where the genetic information in a dna nucleotide sequence is copied into newly synthesized rna molecules

rna polymerase

the enzyme that transcribe a dna sequence into rna molecules

mrna (messenger rna)

single-stranded and carries information from DNA to the ribosome

codons

three base pair sequences

trna (transfer rna)

folds into a three-dimensional structure

one end of the trna will bind to a specific amino acid while the other end of trna contains an anticodon which will pair with the appropriate mrna codon at the ribosome

rrna (ribosomal rna)

folds into a three-dimensional structure

rrna and proteins form ribosomes that perform translation

ribozyme

ribosomal rna that catalyzes reactions needed in translation

promoter

a non-coding binding site for rna polymerase to begin transcription

TATA box

a region in eukaryotic promoters that are rich in thymine and adenine

transcription factors

proteins that help rna polymerase bind to the promoter sequence and begin transcription

template strand

the dna strand being transcribed by rna polymerase

the newly synthesized rna must be ___ to the template dna strand

antiparallel

synonyms for template strand

- minus strand

- noncoding strand

- anti sense strand