Most of the procedures apply to any Type 4 engine in a 72-79 bus. If you don't see particular parts then you've got carbs. I've tagged the carb specific photos. There might be slight differences, such as the way the heater booster is wired but you'll get the general idea.
All the reactions of photosynthesis that are not directly dependent upon light are known as the dark reactions. The dark reactions occur whether there is light present or not. The dark reactions occur in the part of the chloroplast known as the stroma.
Enzymes are then prepared for another reaction. The substrates are then altered and called products. This is the process known as the  lock and key .. The conditions in terms of temperature, pH level and substrate concentration is crucial for an enzyme activity to function effectively.