Where are each of the 4 macromolecules found in a cell?

The four macromolecules are nucleic acids, lipids, carbohydrates, and proteins.

Nucleic acids refer to DNA and RNA. In eukaryotic cells, the majority of DNA is found in the nucleus, with a small amount of mitochondrial DNA in the mitochondria. RNA is found in the nucleus as it is first transcribed, in the cytoplasm where it can be translated, and also in the mitochondria as it is transcribed from mitochondrial DNA. Prokaryotic cells such as bacteria do not have nuclei, and nucleic acids are found in the cytoplasm.

Lipids make up the membranes in the cell. This includes the plasma membrane as well as organelle membranes.

Carbohydrates such as sugars are energy sources and are found in the cytoplasm. Glucose, for example, is metabolized in the mitrochondria to produce energy in the form of adenosine triphosphate (ATP). Carbohydrates also make up the backbone of nucleic acids. Carbohydrates are often covalently linked to lipids or proteins in the plasma membrane, and function mainly for cell recognition.

Lastly, proteins are important for both the structure and function of cells and are found in almost all parts of the cell. Proteins such as actin and myosin make up the cytoskeleton for cell support and are found in the cytoplasm. There are proteins in the nucleic responsible for DNA condensation, replication, and transcription. Degrading enzymes in lysosomes are responsible for digesting macromolecules. Ribosomes, which are made of proteins, reside in the cytoplasm and translate RNA to protein. Proteins are also present as receptors and channels on the plasma membrane to allow for selective passage of molecules into the cell.