Biology lecture final exam Flashcards
what does Release Factor do?
ends translation by recognizing a stop codon in an mRNA sequence
how do tRNAs participate with amino acids and ribosomes to assemble protein chains?
carry amino acids to the ribosome and join with their complementary codons
how is eukaryotic pre-mRNA processed before it becomes mature mRNA?
RNA splicing
Exons
which are parts of the protein-coding sequence in mRNA
introns
The non-coding regions within the gene on a mRNA
Prokaryotic mRNA
molecule that carries genetic information from DNA to proteins
Eukaryotic mRNA
a molecule that carries genetic information from DNA to ribosomes, which translate it into proteins
how do codons specify the production of a protein/polypeptide chain?
by dictating the order of amino acids to be added to the growing chain, with each codon corresponding to a specific amino acid
Transcription
DNA —> RNA
Translation
RNA —> Protien
how is RNA different from DNA with regards to structure?
DNA is typically double-stranded, forming a double helix, while RNA is usually single-stranded
how is RNA different from DNA with regards to synthesis?
RNA is not self-replicating like DNA
how is RNA different from DNA with regards to function?
DNA primarily functions the storage of genetic information
RNA carrying the genetic code from DNA to ribosomes where it is translated into proteins
how do transcription factors work to stimulate the rate of transcription?
binding to specific DNA sequences and either promoting or inhibiting the process
Transcription factors
proteins that regulate transcription
what is the function of promoter?
acts as a binding site for RNA polymerase
what is the function of TATA Box?
define the direction of transcription and also indicates the DNA strand to be read
what is the function of enhancer?
acts as a regulatory element to significantly increase the transcription of a nearby gene
what is the function of silencer?
regulatory element to suppress the transcription of a nearby gene
how does Lac Repressor inhibit transcription of Lac Operon ?
by binding to a specific DNA sequence called the “operator” which is located near the promoter region of the operon, physically blocking RNA polymerase from accessing the promoter and initiating transcription when lactose is not present
Lac Repressor
a protein that controls the transcription of genes in bacteria that metabolize lactose
Lac Operon
a set of genes in bacteria that control the uptake and metabolism of lactose
promoter
The nucleotide sequence in DNA to which RNA polymerase attaches to begin transcription
operon
a group of genes that are transcribed together to create a single (mRNA) molecule that encodes multiple proteins