Answer:
A substance that speeds up a chemical reaction—without being a reactant—is called a catalyst. The catalysts for biochemical reactions that happen in living organisms are called enzymes. Enzymes are usually proteins, though some ribonucleic acid (RNA) molecules act as enzymes too.
Explanation:
enzymes don't change their own reaction. That's because they don't affect the free energy of reactants or the products.
Answer:
Which of the following, if discovered to be true, would most seriously weaken the support for the researchers’ prediction?
The correct answear is B. Naltrexone inhibits morphine from triggering the migration of intestinal bacteria into the bloodstream.
Explanation:
Naltrexone is a non-selective opioid antagonist, it competes with these at the level of the receptors and thus reduces their effects.
The responses A, C, D and E does not weaken the support for the
researches ´ predictions, and are not relevant to the argument.
Answer:
NASA satellites help scientists study Earth and space. Satellites looking toward Earth provide information about clouds, oceans, land and ice. They also measure gases in the atmosphere, such as ozone and carbon dioxide, and the amount of energy that Earth absorbs and emits.
Explanation:
D. Toxic , the other options do not refer to something necessarily harmful to the human body or poisonous. Human hair is ignitable, acid in the stomach corrodes food through chemical reactions so toxic is the only option left.
Answer:
Excitation is the process in which action potentials in the nerve fiber lead to action potentials in the muscle fiber. There is then a rapid fluctuation in membrane voltage at the motor end plate, called the end-plate potential. Areas of the sarcolemma near the motor plate have gates that open, moving ions, which causes the action potential that excites the muscle fiber. The process begins with a nerve signal stimulating a voltage-gated calcium ion channel to open, allowing the ions to enter the axon terminal. The ions stimulate the release of acetylcholine into the synaptic cleft.
