Question

Cells can make proteins that need to be transported out of the cell and moved to another part of the body. Cells also make carbon dioxide as a waste product of cellular respiration. Proteins are large molecules; carbon dioxide is a small molecule. Which best describes how the proteins and carbon dioxide are going to exit the cell? The proteins will be transported through endocytosis; the carbon dioxide will be transported by active transport. The proteins will be transported through exocytosis; the carbon dioxide will diffuse through the membrane. The proteins will be transported by active transport; the carbon dioxide will be transported by osmosis. The proteins will be transported by facilitated diffusion; the carbon dioxide will be transported by exocytosis.

Answer 1

Answer:

The proteins will be transported through exocytosis; the carbon dioxide will diffuse through the membrane.

Explanation:

Diffusion is the passive transport of substances down their concentration gradient. The process moves the substances from the region of higher concentration to that of lower concentration. CO2 is a small molecule and does not have any charge. Small, uncharged molecules can diffuse through the lipid bilayer of the cell membrane. Therefore, CO2 can exit a cell by simple diffusion.

On the other hand, proteins are too large to be transported by diffusion across the cell membrane. The proteins are transported by exocytosis. During exocytosis of proteins, membrane-bound vesicles are formed inside the cell. These vesicles carry proteins in them and are called secretory vesicles. The membrane of the vesicles fuse with the cell membrane of cells and transport the proteins outside the cell.