Inheritance

• Why are proteins so important?

  • Build cells
  • speed up chemical reactions in the body(Enzymes(amylase, protease, lipase))
  • send chemical messages around the body through hormones (FSH, LH, ADH)
  • carries oxygen through haemoglobin.
  • fights bacteria and viruses
• What is a gene?

  a gene is a section of DNA which codes for a protein.
• How is genetic information organised?

  • a genome - all of the DNA found in a cell or living organism.
  • a nucleus - DNA is located here, only in eukaryotic cell.
  • chromosome - an entire strand of DNA is a chromosome.
  • gene - section of DNA that codes for a protein.
• what is DNA?

  polynucleotide
• what is a strand of DNA made from?

  • a phosphate
  • a deoxyribose sugar
  • a base

  
• How many bases are there in DNA and what are they?

  • 4 types of base
  • A
  • T
  • C
  • G
• Which bases are complementary to each other?

  Adenine-Thymine (A - T)

  Guanine-Cytosine (G - C)
• what shape is a DNA?

  double helix shape

  
• what bonds the bases together?

  • for A -T hydrogen bonds hold them together, these are relatively weak.
  • for C-G hydrogen bonds hold them together which are harder to break, as there are more
• what does this picture show?

  sugar phosphate backbone

  
• what does RNA carry?

  a copy of the DNA code
• what bases does RNA contain?

  • A - U
  • C - G
  • T gets replaced with U
• what are the two types of RNA?

  • mRNA
  • tRNA
  • they are both involved in making protiens
• what does mRNA do?

  carries a copy on DNA code out of the nucleus.
• what does tRNA do?

  carries the amino acids into the ribosome for protein synthesis.
• What is transcription?

  • takes place in the nucleus
  • double stranded DNA unzips hydrogen bonds between complementary bases, therefore bonds are broken.
  • RNA nucleotides bind to the template DNA strand, instead of T, U binds to A
  • RNA polymers joins the adjacent RNA nucleotide to make mRNA
  • mRNA detaches and leaves the nucleus though nucleus pore
• what is the triplet code of mRNA called?

  codon
• where does translation occur?

  ribosomme
• what is translation?

  • mRNA binds to ribosome
  • ribosome reads the mRNA's first codon
  • tRNA molecule with the complementary anti-codon to mRNA codon brings amino acids to ribosome
  • ribosome reads second codon, and second tRNA brings second amino acid
  • ribosome joins amino acids together. this repeats until a whole protein is made
• tRNA had anti-codons