Protein Synthesis TGT - Questions

Protein Synthesis TGT - Questions 2 Which type of point mutations can cause the frameshift error? 3 What purpose does the promoter region serve? 4 What is the name of the enzyme that converts DNA sequences into mRNA molecules? 5 In the DNA molecule, one strand is called the template strand. Why is it called this? 6 Define transcription. 7 Where does transcription occur? 8 The metabolism of alcohol requires the activity of the enzyme alcohol metabolise. If no alcohol is present in the human body, very little of the enzyme is present. If someone starts to consume alcohol, the level of the enzyme increases accordingly. Does this model the action of the trp operon or the lac operon? 2 List two alterations that need to be made to the pre mRNA molecule before it can leave the nucleus. 3 Describe the difference between an exon and an intron. 4 When does transcription end? 5 What is the name for the group of enzymes that modify the RNA primary transcripts code? 6 What role do the 5' cap and poly-A tail have in an mRNA molecule? 7 Alanine is a non essential amino acid in humans. This means that the human body has a means to synthesize it from other molecules using enzymes. If alanine is present in ones diet the enzymes are not present. If alanine is not present in ones diet the enzymes are present. In this model, is alanine an inducer or corepressor? Explain. 8 Which codon nucleotide sequence is responsible for setting the ribosome reading frame and initiating translation? 9 How many parts does a ribosome have and what are their names. 2 What is the role of the tRNA molecule in protein synthesis? 3 What is the role of the mRNA molecule in protein synthesis? 4 Where does translation occur? 5 Describe what a codon sequence is and where would you find one? 6 Describe what an anticodon sequence is and where would you find one? 7 When does translation stop? 8 What is the relationship between a codon and an anticodon? 9 An error that causes one amino acid in a protein to be replaced by another is called a mutation? 2 What does a nonsense mutation cause to happen in a translating protein? 3 What determines the types and sequence of amino acids in proteins? 4 Why isn't an error in the third nucleotide of a codon as significant as an error in the first or second nucleotide of a codon? 5 A protein is not made when the terminator sequence of a gene is removed. Explain. 6 A protein is not made when RNA polymerase fails to recognize the promoter sequence. Explain. 7 A protein may not be made when the enzyme that adds the 5' cap is non-functional. Explain. 8 A functional protein will not be made if spliceosomes excise exons and join introns together. Explain. Protein Synthesis TGT - Answers 2 – insertions/additions and deletions 3 –binding site for RNA polymerase to start transcription 4 – RNA polymerase 5 – it is the strand of DNA that is used to make a molecule of mRNA 6 – the conversion of the genetic code in molecules of DNA into molecules of mRNA 7 – nucleus 8 – lac operon 2 – 5’ cap added, poly-A tail added, introns removed 3 – exons contain information for proteins, introns do not 4 – when RNA polymerase reaches the termination sequence on the DNA template strand 5 – spliceosomes 6 – prevent the mRNA from being enzymatically destroyed in the cytoplasm 7 – corepressor, when present it activates the repressor to attach to the operator → no transcription 8 - AUG 9 – 2, large subunit and the small subunit 2 – to bring the correct amino acid to the ribosome 3 – to take the code out of the nucleus to the ribosome 4 - cytoplasm 5 – a sequence of 3 nucleotides; in mRNA molecules 6 – a sequence of 3 nucleotides; in tRNA molecules 7 – when a stop codon is reached by the ribosome 8 – they are complements of one another 9 - missense 2 – premature stop codon/create a stop codon before the end of the mRNA 3 – the sequence of nucleotides in molecules of DNA 4 – the first two nucleotides are essential for determining which amino acid is coded for, the third is not as important 5 – transcription does not stop until another terminator sequence is reached, mRNA has two genes in it as well as the “junk” DNA between those genes 6 – transcription does not occur 7 - ribosome does not recognize the mRNA to start translation OR the mRNA is degraded in the cytoplasm 8 – exons contain the information to make the correct protein, introns do not