Gene Expression Flashcards
What is transcription??
Is the first step of gene expression.
It’s when a particular segment of DNA is copied into mRNA by the enzyme rna polymerase.
What is translation ??
Is the process in which cellular ribosomes create proteins.
So the mRNA produced by transcription from DNA- is decoded by a ribosome to produce a specific amino acid chain, or polypeptide.
Which is first? Translation or transcription??
- Transcription
2. Translation
Transcription process?? The first step as well as the initiation.
- DNA copied into mRNA stored in the nucleus
- Initiation- transcription is initiated by a chemical messenger
- chemical messenger attaches to epigenome at a specific point along DNA.
- rna polymerase attaches to a chemical messenger
What is protein synthesis ??
Is the process by which the genetic code puts together proteins in the cell.
What is the elongation process of transcription??
- RNA polymerase moves along DNA- where it reaches the start sequence (triplets)
- which separates hydrogen bond
- template strand is exposed and copied
- complementary free nucleotides from nucleus attaches to form mRNA
- adenine with uracil
- guanine with cytosine
What is the termination process of transcription?
- RNA polymerase- reaches stop sequence
- mRNA strand is released and undergoes splicing to remove introns (junk)
- mRNA leaves the nucleus- via nuclear pore and travels through the cytoplasm to a ribosome
- DNA reforms a double helix
What is the first state of translation as well as the initiation ?
It’s the conversion of the genetic code on mRNA into amino acids to from proteins
- Initiation- mRNA enters ribosome
- ribosome moves along mRNA and when start codon is Rachel translation begins
What is the elongation process of translation?
- As mRNA is moving through ribosome, codons are being read
- tRNA contains anticodon which corresponds to a specific amino acid. It collects amino acids and deposits it at ribosome.
Ribosome forms peptide bonds between amino acids which forms polypeptide chain
What is the termination process of translation?
- When stop codon reached- translation stops
- polypeptide chains sent to Golgi apparatus
What is the protein packaging process of translation?
When it goes from primary, to secondary, to tertiary, to quaternary
What are introns ? Exons? What is the process to get rid of the introns ?
Introns- junk
Exons- useful
Splicing- when introns are gotten rid of and Exons remain.
