Ancient photosynthetic prokaryotes were very important in the history of life because theya. produced the oxygen in the atmosphere. b. are the oldest known archaea. c. were the first multicellular organisms. d. showed that life could evolve around deep-sea vents.

Option A.

Produced the oxygen in atmosphere

Explanation:

Photosynthetic prokaryotes have chlorophyll in their cytoplasm. The chlorophyll is join to protein to form chlorosome(light harvesting molecules) which in turn convert light energy to chemical energy and fixed carbon dioxide in the atmosphere by synthesizing light in sugar , thereby release oxygen to the atmosphere. The photosynthetic prokaryotes include cyanobacteria, algae e.t.c

when it's short and dry.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products