Researchers who study those rods cells have performed a series of experiments to better understand this phototransduction pathway and the role of this PDE protein in patients that suffer from night blindness. In one experiment, researchers have measured the cytosolic concentration of cGMP (cyclic- GMP) under different light intensities (exposure = 10 min) in both the presence and the absence of the PDE6i inhibitor. The results are as follow: the cytosolic concentration of cGMP (cyclic-GMP) decreases as light intensity increases, but only in the absence of the PDE6i inhibitor (see figure below). Without PDE6i cGMP concentration (A.U) 25 20 15- 10- 0 0 0.1 0.2 0.3 Light intensity (A.U) -25 C. It is a messenger RNA D. It is a hormone E. It is a phospholipid -20 -10 0.4 5 0 GMP concentration (A.U) cGMP concentration (A.U) 25 20 15- 10- 0 0.1 With PDE6i 0.2 0.3 Light intensity (A.U) 25 0.4 20 -0 GMP concentration (A.U) 10. What is the likely function of the cytosolic cGMP in this phototransduction pathway? A. It is a competitive inhibitor of PDE B. It is a second messenger

Researchers who study those rods cells have performed a series of experiments to better understand this phototransduction pathway and the role of this PDE protein in patients that suffer from night blindness. In one experiment, researchers have measured the cytosolic concentration of cGMP (cyclic- GMP) under different light intensities (exposure = 10 min) in both the presence and the absence of the PDE6i inhibitor. The results are as follow: the cytosolic concentration of cGMP (cyclic-GMP) decreases as light intensity increases, but only in the absence of the PDE6i inhibitor (see figure below). Without PDE6i cGMP concentration (A.U) 25 20 15- 10- 0 0 0.1 0.2 0.3 Light intensity (A.U) -25 C. It is a messenger RNA D. It is a hormone E. It is a phospholipid -20 -10 0.4 5 0 GMP concentration (A.U) cGMP concentration (A.U) 25 20 15- 10- 0 0.1 With PDE6i 0.2 0.3 Light intensity (A.U) 25 0.4 20 -0 GMP concentration (A.U) 10. What is the likely function of the cytosolic cGMP in this phototransduction pathway? A. It is a competitive inhibitor of PDE B. It is a second messenger

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter18: Glycolysis

Section: Chapter Questions

Problem 25P: Using the ActiveModel for phosphofructokinase (Trypanosoma), describe the difference between the...

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To further investigate the cellular response in photoreceptor cells, we will now look at the actual effect of cGMP within the phototransduction pathway. Again, we will compare what happens in the dark and in the presence of light to understand how an electric signal is generated in either condition. Comparing both conditions (in the dark or under the light), researchers have measured the molar concentration of cytosolic CGMP and recorded the membrane potential of rod cells by placing micro- electrodes on either side of their plasma membrane (see figure below). • A negative membrane potential means that there are more negatively charged ions inside the cell compared to outside the cell, or equivalently, that there are less positively charged ions inside the cell compared to outside the cell. • A positive membrane potential means that there are more negatively charged ions outside the cell compared to inside the cell, or equivalently, that there are less positively charged ions outside…
To further investigate the cellular response in photoreceptor cells, we will now look at the actual effect of cGMP within the phototransduction pathway. Again, we will compare what happens in the dark and in the presence of light to understand how an electric signal is generated in either condition. Comparing both conditions (in the dark or under the light), researchers have measured the molar concentration of cytosolic cGMP and recorded the membrane potential of rod cells by placing micro-electrodes on either side of their plasma membrane (see figure below). A negative membrane potential means that there are more negatively charged ions inside the cell compared to outside the cell, or equivalently, that there are less positively charged ions inside the cell compared to outside the cell. ● A positive membrane potential means that there are more negatively charged ions outside the cell compared to inside the cell, or equivalently, that there are less positively charged ions outside the…
The muscle enzyme lactate dehydrogenase catalyzes the reaction NADH and NAD+ are the reduced and oxidized forms, respectively, of the coenzyme NAD. Solutions of NADH, but not NAD+, absorb light at 340 nm. This property is used to determine the concentration of NADH in solution by measuring spectrophotometrically the amount of light absorbed at 340 nm by the solution. Explain how these properties of NADH can be used to design a quantitative assay for lactate dehydrogenase.
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A number of auxotrophic mutant strains were isolated from wild-type haploid Neurospora crassa. These strains responded to the addition of certain nutritional supplements to minimal culture medium either by growth (+) or no growth (0) The data from this experiment are presented in the table below. Diagram a biochemical pathway, complete with positions of intermediates, that is consistent with the data. Indicate where in the pathway each mutant strain is blocked.