Which statement about enzymes is true? An enzyme functions to increase the activation energy in a reacton.
Enzymes are proteins that function as catalysts in nonliving things.
Each enzyme can catalyze many different biochemical reactions.
Enzymes and substrates fit together like a lock and key.

Enzymes and substrates fit together like a lock and key since, in one enzymatic reaction, only the correct substrate (i.e., the key) binds to its corresponding enzyme (i.e. the lock).  

Explanation:

An enzyme (or catalyst) is one protein that has catalytic functions, being therefore capable of accelerating chemical reactions. The enzymes are known to control the rate of these chemical reactions (i.e., catalysis) without suffering alterations during these processes. Thus, the enzymes are proteins that catalyze chemical reactions that are not favored under normal conditions. Moreover, one enzyme may catalyze more than one chemical transformation, as well as the same reaction may be catalyzed by two or more enzymes.

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c

the atmospheric gas that forms a mild acid when dissolved in water is called carbon dioxide. the correct answer is a. 2.) chemical weathering would cause an inscription on a marble headstone to become harder and harder to read over time.