Ribosomes consist of two major components: the small ribosomal subunits, which read the RNA, and the large subunits, which join amino acids to form a polypeptide chain. Each subunit comprises one or more ribosomal RNA (rRNA) molecules and a variety of ribosomal proteins (r-protein or rProtein).
The gravitational potential energy of the ball decreases as it rolls down the hill while the gravitational kinetic energy of the ball increases due to its acceleration in velocity.
The large majority of spiral galaxies are flat, rotating disks. Within the disk, there are stars, dust, and gas. The disk also contains spiral arms and a central concentration of stars known as the bulge of the galaxy.
