what is the role of the retinal molecule in the process of light stimulated signal transduction in the eye ? explain in a paragraph
Vision is based on the absorption of light by photoreceptor cells in the eye. These cells are sensitive to light in a relatively narrow region of the electromagnetic spectrum.Vertebrates have two kinds of photoreceptor cells, called rods and cones because of their distinctive shapes. Cones function in bright light and are responsible for color vision, whereas rods function in dim light but do not perceive color. A human retina contains about 3 million cones and 100 million rods.
Visual phototransduction is the sensory transduction of the visual system. It is a process by which light is converted into electrical signals in the rod cells, cone cells and photosensitive ganglion cells of the retina of the eye.
Light closes cGMP-gated sodium channels, reducing the influx of both Na+ and Ca2+ ions. Stopping the influx of Na+ ions effectively switches off the dark current. Reducing this dark current causes the photoreceptor to hyperpolarise, which reduces glutamate release which thus reduces the inhibition of retinal nerves, leading to excitation of these nerves. This reduced Ca2+ influx during phototransduction enables deactivation and recovery from phototransduction.
what is the role of the retinal molecule in the process of light stimulated signal transduction...
Section 12.3 20) Which process is NOT a feature of visual signal transduction? e. activation of a cGMP phosphodiesterase 1. replacement of all-trans-retinal catalyzed by transducin 8. light absorption by 11-cis-retinal h. change in cell membrane potential Section: 12.3 GPCRs in Vision, Olfaction, and Gustation Section 12.4 21) Receptor tyrosine kinases: e. are dimers. f. do not regulate gene expression. 8. engage in extensive cross talk with other signal transduction systems. h. bind insulin. Section: 12.4 Receptor Tyrosine kinases Section...
The human eye contains a molecule called 11 - cis - retinal that changes shape when struck with light of sufficient energy, which results in an electrical signal being sent to the brain. The minimum energy required to change the conformation of 11 - cis - retinal within the eye is 164 kJ/mol. Calculate the longest wavelength (in nm) visible to the human eye.
5. What is the function of phosphatases in signal transduction processes? Amplify the transduction signal so it affects multiple transducers Amplify the second messengers such as CAMP Inactivate protein kinases and turn off the signal transduction Prevent a protein kinase from being reused when there is another extracellular signal Move the phosphate group of the transduction pathway to the next molecule of a series
explain signal transduction and the sensory motor pathways of animals using the examples of the vertebrate ear and eye
Question 45 (1 point) Put the following events in the process of signal-transduction in order: i) A conformational change in the signal-receptor complex activates an enzyme, ii) Protein kinases are activated. ill) A signal molecule binds to a receptor. iv) Target proteins are phosphorylated iii), i), ii), iv) i), ii), iii), iv) i), ill), iv), ii) iii), iv), i), ii)
Place the events in the correct sequence to explain signal transduction Molecular messenger transmits signal to effector proteins. Plant cell exposed to increased gibberellins. Effector proteins influence gene expression. Receptor molecule senses stimuli. The proteins produced influence cell division and elongation. Receptor molecule is converted to activated form. Receptor molecule senses stimuli.
Thanks What is quorum sensing (members, role)? What molecular systems allow for this process to occur? Two-component signal transduction: How does this mechanism allow for response to the extracellular environment?
Which of the following statements concerning signal transduction by the insulin receptor is NOT correct? A. The insulin receptor substrate protein IRS-1 in its phosphorylated form activates other proteins. B. The pathway for insulin-stimulated transcription of specific genes involves the protein Ras. C. The insulin receptor phosphorylates itself in the activation process. D. Insulin stimulation of the insulin receptor initiates a cascade of events causing activation of glycogen synthase. E. The receptor protein kinase activity is specific for serine residues...
3. Many membrane process such as transport or signal transduction depends on the fluidity of lipids membrane. How fatty acids and cholesterol effect the fluidity of the membrane.
3. Many membrane process such as transport or signal transduction depends on the fluidity of lips membrane. How fatty acids and cholesterol effect the fluidity of the membrane.