Transcription and Translation Flashcards
What is gene expression?
Gene expression refers to the process by which genetic information stored in the DNA is converted into functional products, such as proteins or non-coding RNA molecules, that carry out various cellular functions.
What is the mechanism of gene expression?
Gene expression is the process by which DNA is used to make proteins, which then go on to perform various important functions in the body.
What are examples of proteins?
The protein could be an enzyme, hormone or receptor.
What is the process of gene expression?
Transcription, processing, non coding RNA maturation, RNA export, translation and protein folding.
What is transcription?
Transcription is the process by which a segment of DNA is used to generate an RNA template.
The DNA segment is “read” by an enzyme called RNA polymerase, which produces a strand of RNA that is complimentary to the DNA.
In this complementary RNA strand, all thymine bases are replaced by uracil.
What is processing?
This primary RNA transcript is then modified to convert it into mature messenger RNA (mRNA) that can be used in translation.
The mRNA undergoes splicing to remove the non-coding parts of the transcript (introns) so that only the coding sections (exons) remain.
What is Non-coding RNA maturation?
Non-coding regions of RNA (ncRNA) are transcribed as precursors which are then processed further.
For example, these regions may be transcribed as pre-ribosomal RNA (pre-rRNA) which then undergoes cleavage to become ribosomal RNA (rRNA).
What is RNA export?
The majority of mature RNA is then transported from the nucleus to the cytoplasm.
Although some RNAs function in the nucleus, most are carried through pores in the nucleus into the cytosol, including all RNAs involved in protein synthesis.
What is translation?
The final mRNA carries the information needed to code for proteins. Every three base pairs on the mRNA corresponds to a binding site for a transfer RNA (tRNA) which carries an amino acid.
The amino acids are then linked together in a chain by a ribosome to create a rudimentary protein chain.
What is protein folding’?
The long chain of amino acids folds to form a three-dimensional structures using enzymes called chaperones.
This three-dimensional structure is the final, functional form of the protein. (mentioned more in other slides)
What are the main DNA control elements?
Promoters and terminators as they are critical components of gene expression in living organisms.
What is their key role?
In regulating the transcription of DNA into RNA, which in turn determines the synthesis of proteins and other functional molecules.
What are promoters?
Promoters are DNA sequences located upstream of the transcription start site of a gene.
They serve as binding sites for proteins called transcription factors, which recruit RNA polymerase, the enzyme responsible for synthesizing RNA, to the correct position on the DNA.
What helps determine where RNA polymerase begins transcription?
Promoters contain specific DNA motifs, such as the TATA box and the transcriptional start site (TSS) that helps determine this.
What happens after this?
Transcription factors recognize these motifs and bind to the promoter, facilitating the assembly of the transcription initiation complex, which includes RNA polymerase and other proteins.
