I believe it is the nitrogen base. Adenine pairs with Thymine, and Cytosine pairs with Guanine.
:)
The effect of a catalyst is to increase the speed of the reaction, this is the speed at which reactants, A and B, are consumed, ant the product, C, is produced.
Given that when C is produced the solution bubbles, the bubbles are an indication of progression of the reaction.
The greater the speed of reaction, the earlier the reaction will end and the earlier the bubbles will stop.
So the student can identify the catalyst because the bubbles will stop first.
Answer: <span>The test tube that stops bubbling first contains the catalyst.</span>
If your body lacks enzymes that break down carbohydrates, it would be unable to get sugar molecules for energy production. If you lacked the enzyme to digest proteins, you may not absorb enough amino acids?
Let's think of it like this. We have an energy crisis, but how can we solve it? There are three steps. First, we need to recognize that we HAVE a problem that needs to be fixed. Then, we need to determine what's causing the problem. Finally, we need to change how we act in order to solve the problem. Now, let's look at the options.
Is A correct, leaving our behavior unchanged? NO: if we know the cause of the problem, we still need to solve it! What about B: the problems are ignored? NO: you can't solve a problem unless you know it's a problem. C? NO: to solve a problem, you need to find out what's causing it. Finally, let's look at D: behavior is changed after cause is identified. This is correct: not only do we know why it's happening, but we're fixing it!
Answer: D