1.3 + 1.5 - gene expression and genome

• define the genome?

  The entire hereditary information in our DNA
• exons are coding regions of DNA
• introns are non coding regions of DNA
• function of exons?

  produce specific proteins
• function of introns?

  Regulate transcription

  transcribed into t/r RNA but not translated
• RNA is single stranded whereas DNA is double stranded
• RNA has a ribose sugar whereas DNA has a deoxyribose sugar
• DNA has base Thymine but RNA has base Uracil
• What are the 3 types of RNA?

  mRNA, tRNA, rRNA
• function of mRNA?

  carries a complimentary copy of the DNA code from the nucleus to the ribosome
• what is rRNA?

  forms the ribosome along with proteins
• what is the function of tRNA?

  transfer amino acids to the ribosome during protein synthesis
• What are A and B?

  A) Amino acid attachment site

  B) Anti-codon

  
• Function of RNA polymerase?

  unwinds double helix by breaking hydrogen bonds and attaches free complimentary RNA nucleotides to make a primary transcript
• Where does transcription occur?

  nucleus
• where does translation occur?

  ribosome
• Exons from the primary transcript are joined to form a mature mRNA transcript
• What does RNA splicing do?

  removes introns from the primary transcript and results in a mature mRNA transcript
• What is alternative RNA splicing?

  a process which creates different proteins from one gene
• during alternative RNA splicing, the order of the exons on the primary transcript remain unchanged
• What happens during translation?

  the mature transcript is translated into a polypeptide using tRNA and rRNA
• translation begins at the start codon and stops at the stop codon
• Amino acids are joined by peptide bonds
• What is a string of amino acids called?

  polypeptide chain
• Define phenotype?

  the physical appearance determined by the proteins produced as a result of gene expression and environmental factors
• Define genotype?

  the alleles that an organism has for a particular characteristic, normally written as letters
• what is polymerase?

  an enzyme that synthesises DNA/RNA chains from single nucleotides
• is DNA polymerase or RNA polymerase required for PCR?

  DNA
• every 3 bases on an mRNA strand are called codons
• 3 bases on tRNA is called an anti-codon
• What is a peptide bond?

  a covalent chemical bond formed beween two amino acids