Cards (37)

    • Who is the presenter of the A Level Biology video?
      Miss Estrich
    • What are the three key features of the genetic code?
      Degenerate, universal, and non-overlapping
    • What is a start codon?
      Three bases at the start of a gene
    • What does the start codon code for?
      Amino acid methionine
    • What are the three bases of the start codon on DNA?
      TAC
    • What is the function of a stop codon?
      It signals the end of translation
    • How many stop codons are there?
      Three
    • What happens when the ribosome reaches a stop codon?
      The ribosome detaches and translation stops
    • What does it mean that the genetic code is degenerate?
      Most amino acids are coded by multiple triplets
    • How many different amino acids are there?
      Twenty
    • What is the mathematical formula to prove the genetic code's combinations?
      4n4^n
    • If the genetic code was one base, how many amino acids could it code for?
      Four
    • If the genetic code was two bases, how many combinations would there be?
      Sixteen
    • How many combinations does a three-base code provide?
      Sixty-four
    • What is a silent mutation?
      A mutation that does not affect the protein
    • What does it mean that the genetic code is universal?
      Same triplet codes for the same amino acid
    • Why is the universality of the genetic code important in gene technologies?
      It allows gene transfer between species
    • What does non-overlapping mean in the genetic code?
      Each base is part of only one triplet
    • What is the advantage of a non-overlapping code?
      Minimizes impact of mutations on proteins
    • What are introns?
      Sections of DNA that don't code for amino acids
    • What percentage of DNA is made up of introns?
      Over 90 percent
    • What are exons?
      Sequences of bases that code for amino acids
    • What is the difference between the genome and the proteome?
      The genome is DNA; the proteome is proteins
    • How does the genome of different organisms vary?
      It varies widely in size and composition
    • How many DNA base pairs are in the human genome?
      About three billion
    • Why do specialized cells produce different proteins?
      They respond to their specific needs
    • What is gene regulation?
      Turning genes on and off as needed
    • What was the first hypothesis regarding genes and enzymes?
      One-gene-one-enzyme hypothesis
    • Why was the one-gene-one-enzyme hypothesis reconsidered?
      Not all proteins are enzymes
    • What is haemoglobin's function?
      Transporting oxygen in the blood
    • What is the structure of haemoglobin?
      Composed of four polypeptide chains
    • What hypothesis was proposed after the one-gene-one-enzyme hypothesis?
      One-gene-one-polypeptide hypothesis
    • What does the one-gene-one-polypeptide hypothesis state?
      Each gene contains multiple triplet codes
    • What are the characteristics of the triplet codes mentioned in the hypothesis?
      Non-overlapping, degenerate, and universal
    • What does each triplet code code for?
      One amino acid
    • What do amino acids combine to form?
      A polypeptide chain
    • What are the key features of the one-gene-one-polypeptide hypothesis?
      • Each gene contains multiple triplet codes
      • Triplet codes are non-overlapping
      • Triplet codes are degenerate
      • Triplet codes are universal
      • Each triplet codes for one amino acid
      • Amino acids combine to form a polypeptide chain