retinal

Examples of retinal in the following topics:

• Transduction of Light

  • When light hits a photoreceptor, it causes a shape change in the retinal, altering its structure from a bent (cis) form of the molecule to its linear (trans) isomer.
  • This isomerization of retinal activates the rhodopsin, starting a cascade of events that ends with the closing of Na+ channels in the membrane of the photoreceptor.
  • Thus, the visual system relies on changein retinal activity, rather than the absence or presence of activity, to encode visual signals for the brain.
  • (a) Rhodopsin, the photoreceptor in vertebrates, has two parts: the trans-membrane protein opsin and retinal.
  • When light strikes the retinal, it changes shape from (b) a cis to a trans form.

• Bacteriorhodopsin

  • Each chain has seven transmembrane alpha helices and contains one molecule of retinal buried deep within, the typical structure for retinylidene proteins.
  • It is the retinal molecule that changes its conformation when absorbing a photon, resulting in a conformational change of the surrounding protein and the proton pumping action.
  • Reprotonation of the retinal molecule by restores its original isomerized form.

• Magnification and Resolution

  • The labels represent various parts of the human eye: Bruch membrane (B); choroid (C); retinal pigment epithelium (RPE); and retinal rod cells (R).

• Development of Vision

  • The optic cup then delaminates into two layers: the neural retina and the retinal pigment epithelium.
  • It is critical for the induction of the retinal pigment epithelium and the optic nerve.

• Perceiving Motion

  • Motion is perceived when two different retinal pathways, which rely on specific features and luminance, converge together.

• Other Infectious Eye Diseases

  • Cytomegalovirus retinitis, also known as CMV retinitis, is an inflammation of the retina of the eye that can lead to blindness.

• Tissues and Aging

  • The labels represent various parts of the human eye: Bruch membrane (B); choroid (C); retinal pigment epithelium (RPE); and retinal rod cells (R).

• Antiviral DNA Synthesis Inhibitors

  • It is also used to treat cytomegalovirus infection (CMV) and specifically CMV retinitis.

• Perceiving Depth, Distance, and Size

  • When an object moves toward an observer, the retinal projection of the object expands over a period of time, which leads to the perception of movement in a line toward the observer.

• Resolution of the Human Eye

  • Initial dark adaptation takes place in approximately four seconds of profound, uninterrupted darkness; full adaptation, through adjustments in retinal chemistry, is mostly complete in thirty minutes.