Some substances pass through small holes in the surface cell membrane. This is called diffusion and does not require the cell to expend energy. Oxygen gets into a cell and carbon dioxide (the product of respiration reactions) leaves it this way.
multiple amino acids are linked together by peptide bonds, thereby forming a long chain. The long chain will coil together which creates a protein. After the proteins are made they are imported to the mitochondria or chloroplasts.
