d.Large molecules, such as proteins, usually are not transported across cell membranes.e.Ions are typically transported by special proteins that form membrane channels.Correct! The false statement is c. Sugars such as glucose are always transported by active transport rather than by facilitated diffusion carriers.14. Uniporters are:a.proteinsb.facilitated diffusion carriersc.often used to transport amino acids and sugars within the human body✔d.all of the aboveCorrect! The correct answer is d. all of the above.15. Animal cells contain membrane vesicles called lysosomes, filled with enzymes that can degrade proteins, lipids, nucleic acids, and other biomolecules. These enzymes are most effective at acid pH, and it can be experimentally shown that the pH inside lysosomes is about 5.0, whereas the pH of the cell cytoplasm is close to 7.0. The diagram (at right) illustrates one lysosome inside a cell. Which of the following is the most likely explanationfor how the cell maintains such a high concentration of protons (H+ions) inside the lysosome?