KA 3: DNA and the Production of Proteins

• What do chromosomes contain in cells?

  Genetic information
• What molecule are chromosomes made up of?

  Deoxyribonucleic acid (DNA)
• How are DNA molecules structured?

  They are composed of two twisted strands
• What shape does the DNA molecule form?

  Double helix
• What are the four types of bases in DNA?

  Adenine, Thymine, Cytosine, Guanine
• How are the two strands of DNA held together?

  By weak bonds between complementary bases
• Which bases pair together in DNA?

  C with G and A with T
• What is a gene?

  A section of DNA that codes for a protein
• What does the order of bases in a gene determine?

  The order of amino acids in a protein
• What is produced when a protein is made from DNA?

  A complementary copy called messenger RNA (mRNA)
• Where is mRNA made?

  In the nucleus
• What happens to mRNA after it is made?

  It leaves the nucleus and attaches to ribosomes
• What determines the order of amino acids in a protein?

  The order of bases on the mRNA molecule
• How do different proteins vary?

  They have different amino acid sequences
• What does the different amino acid sequences in proteins affect?

  Their different functions