Corals obtain energy from tiny photosynthetic algae, called zooxanthellae, which live inside the coral's tissue. how do you think corals would be affected by cloudy, muddy water?

Cloudy and muddy water will interfere with the penetration of light to particular depth in water where coral are found. The algae in the symbiotic relationship with the sponges will be unable to photosynthesize. This way, the sponges will lose the algae and become ‘bleached’. 

Photo means light and synthesis means combination so combination of light

Active site is where they touch.