Answer:
Active transport: movement against a gradient To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the proper concentrations of ions and molecules in living cells.
Answer:
B. surface runoff
Explanation:
Surface runoff is the flow of water that occurs when excess storm water, melt water, or other sources flow over the Earth's surface.
hope this helps
It's controversial because the best source of stem cells is a human embryo (an aborted fetus).
<span>(3) parasite. Parasites are organisms that live on other organisms and cause harm to them.</span>
Answer:
D. Allosteric activator
Explanation:
In an enzyme, the allosteric site is a site/motif different from the active site, (i.e., the site with catalytic activity) which is able to interact with regulatory effector molecules in order to activate or inhibit enzymatic activity by influencing the tridimensional (3D) structure of the enzyme. An allosteric activator is an effector molecule with the ability to bind to a specific enzyme at a different site than the active site, thereby modifying the shape of the enzyme and increasing the affinity of this enzyme for its substrate. Moreover, Adenosine monophosphate (AMP) is a nucleotide composed of a phosphate group, a sugar ribose, and an Adenine (A) base. This effector molecule (AMP) has shown to allosterically stimulate diverse enzymes in physiological conditions (e.g., AMP-activated protein kinase).
