The predominant cells in blood are the red blood cells (RBC) which contains a protein called hemoglobin. Hemoglobin is the principal determinant of the color of blood. Arterial blood and capillary blood are bright red, as oxygen imparts a strong red color to the heme group.
Concept 21 RNA is an intermediary between DNA and protein. DNA is found mostly in the cell nucleus, but another type of nucleic acid, RNA, is common in the cytoplasm. Watson and Crick proposed that RNA must copy the DNA message in the nucleus and carry it out to the cytoplasm, where proteins are synthesized. Crick also predicted the existence of an adaptor molecule that reads the genetic code and selects the appropriate amino acids to add to a growing polypeptide chain.
1 Ribosomal RNA (rRNA) is a component of cell organelles called ribosomes. 2  A ribosome consists of ribosomal proteins and rRNA. 3  Ribosomes are typically composed of two subunits: a large subunit and a small subunit. 4  Ribosomal subunits are synthesized in the nucleus by the nucleolus.NA molecules are produced in the nucleus of our cells and can also be found in the cytoplasm. The three primary types of RNA molecules are messenger RNA, transfer RNA and ribosomal RNA. Some RNAs, known as small regulatory RNAs, have the ability to regulate gene expression.