What happens during light & dark within the rod cells?

LIGHT

• Rhodopsin molecule breaks down into retinal & opsin
• Opsin activates a series of membrane-bound reactions
  • Hydrolysis of a cyclic nucleotide molecule attached to the cation channel (in the outer segment)
  • Breakdown = closes cation channels
• Influx of Na+ into the rod decreases
• Inner segment continues to pump Na+ out
  • Inside cell more -ve 'Hyperpolarised'
• Release…