Carbon Dioxide and wastes are transferred for oxygen. The  blood then travels to the left atrium by the pulmonary artery and  then to the left ventricle. The blood leaves the heart by the aorta  to the other parts of the body.. The circulatory system is the organ system that carries substances around our body. There is no such thing as a circulary system.
Overview [edit]. The purpose of the ribosome is to translate messenger RNA (mRNA) to proteins with the aid of tRNA. In eukaryotes, ribosomes can commonly be found in the cytosol of a cell, the endoplasmic reticulum or mRNA, as well as the matrix of the mitochondria.
Cells need to make proteins. Enzymes made of proteins are used to help speed up biological processes. Other proteins support cell functions and are found embedded in membranes. Proteins even make up most of your hair. When a cell needs to make proteins, it looks for ribosomes. Ribosomes are the protein builders or the protein synthesizers of the cell. They are like construction guys who connect one amino acid at a time and build long chains.