How do autotrophs capture the energy in sunlight?

1 Answer
Mar 17, 2018

Answer:

Sunlight is absorbed by the green pigment, chlorophyll and the solar energy is converted into chemical energy in the form of #"ATP"#.

Explanation:

Autotrophs capture sunlight by the pigment chlorophyll and is used for the synthesis of glucose #(C_6H_12O_6)# from simple, inorganic substances like #CO_2# and #H_2O# during photosynthesis.

Photosynthesis occurs in 2 steps:

1. Hill's reaction

2. Dark reaction

Light reaction or Hill's reaction involves capturing sunlight and converting solar energy into chemical energy in the form of #"ATP"#. This occurs by breakdown of water into #H^+# ions and #O^(2-)# ions. This is termed by photolysis of water. Excited electrons from #O^(2-)# pass through a series of electron carriers, losing energy during their passage. This energy is converted into #"ATP"#. The remaining#H^+# ions reduce #"NADP"# to #"NADPH"#.

#"ATP"# and #"NADPH"# produced during light reaction are used in the dark reaction for reduction of #CO_2# to #C_6H_12O_6#.