It is a major component of chlorophyll, the most important pigment needed for photosynthesis, as well as amino acids, the key building blocks of proteins. It is also found in other important biomolecules, such as ATP and nucleic acids.
The nucleus contains the cell 's DNA and directs the synthesis of ribosomes and proteins. Found within the nucleoplasm, the nucleolus is a condensed region of chromatin where ribosome synthesis occurs.
Newtonian gravity is what scientists believe will stop the universe’s expansion. This attraction would have to overcome the propulsive force of dark energy expansion, thus causing the compression of all the matter in the universe back into a small, hyperdense singularity.