Explanation:
Cell membranes are selectively permeable. Some solutes cross the membrane freely, some cross with assistance, and others do not cross at all. A few lipophilic substances move freely across the cell membrane by passive diffusion. ... Large molecules do not cross intact cell membranes, except in certain special cases.
Answer:
Frogs have smooth or slimy skin that is moist, whereas toads have thicker, bumpy skin that is usually dry. All toads are poisonous, while frogs are not.
Answer: C
Explanation: Thymine pairs with Adenine and Cytosine pairs with Guanine.
Answer: Denaturing
Explanation: Enzymes are made of amino acids that are linked by bonds, amongst those bonds are hydrogen bonds that are very weak. High temperatures and low pH(acidity) breaks those bonds changing the molecular conformation of the enzymes. That way they denature and loss the ability to perform their functions. High temperatures and acidity alter the structure of their active site preventing the substrate from binding to them. While high temperatures denatures enzymes, low temperature renders them inactive.
