#1.which of the following best identifies base 1? a) purine. b) pyrimidine. c) cytosine. d) nucleotide. #2. which of the following could base 2 bind with? a) a purine. b) a guanine. c) an adenine. d) a pyrimidine.

The human eye contains a molecule called 11-cis-retinal that changes shape when struck with light of sufficient energy. the change in shape triggers a series of events that results in an electrical signal being sent to the brain that results in vision. the minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 kj/mol.