Doing a practice quiz need help.

Which organelle breaks down sugar molecules that supply energy to the cell ?

What is the significance of the protein-lined pits? a. protein attracts other proteins needed for atp synthesis within the cell. b. protein-lined pits are able to transport one molecule at a time down the concentration gradient within the cell. c. the polarity of proteins allows other polar molecules to attach and be transported in the cell by transport channels. d. receptors within the pits allow ligands to fuse and be transported into the cell by endocytosis.

Hemoglobin is a proton that carries oxygen around the body what is hemoglobin made from