In some single-celled protozoans living in fresh water, such as the paramecium, contractile vacuoles are
organelles are used to pump excess water out of the cell.
Explain why a paramecium would require contractile
vacuoles while a similar protozoan living in salt water
would not.

step 1: replication fork formation.

step 2: primer binding.

step 3: elongation.

step 4: termination.

explanation:

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it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.

what? are the statements?