Which statement about the binding of enzymes and substrates is correct?
a. substrate molecules bind to the active site of the enzyme only by weak bonds, such as hydrogen bonds or hydrophobic attraction.
b. substrate molecules fit into the active site of an enzyme like a key fits into a lock.
c. when substrate molecules bind to the active site of the enzyme, the enzyme undergoes a slight change in shape.

Answers a. and c. should be correct.

Explanation:

Enzymes help increase the rate in which a chemical reaction occurs. The interactions between the enzyme and the substrate induced conformational changes in the enzyme that facilitate and strengthen the binding with its substrate. That is called the induced fit model. Before this model, scientists explain the binding of enzyme and substrate as a “lock-and-key”. There are four type of weak interactions by which enzymes and substrates bind each other: 1) hydrogen bonds, 2) electrostatic interactions, 3) hydrophobic interactions and 4) van der Waals interactions. The strong binding between the enzyme and its substrate is the addition of several weak interactions working together.

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.