GUNILLA ELAM / SCIENCE PHOTO LIBRARY GUNILLA ELAM / SCIENCE PHOTO LIBRARY
Illustration of an influenza virus (left) and a bacterium (right). The core of the virus is its genetic material, strands of single-stranded RNA (ribonucleic acid, blue). Surrounding these is a capsid protein coat lipid envelope. Embedded in the envelope are two types of surface protein: haemagglutinin (H, pink) and neuraminidase (N, yellow). These determine the strain of virus and are used for recognising and binding to the host cell. Bacteria are single-celled prokaryotic organisms. The bacterial cell contains DNA (pink strands), the genetic material, and ribosomes (pink dots), the site of protein synthesis. It is surrounded by a plasma membrane, cell wall and capsule. Within the capsule are pili (short green strands), which are used to adhere to surfaces, and flagella (long green strands), which are used for locomotion.
Model release not required. Property release not required.