Molecular mechanism of vision

During a biology class, Rohan learned about the components of rhodopsin, a crucial protein in the human eye. His teacher asked the class, "Which of the following is the light-sensitive chromophore in rhodopsin?"

• Retinol

• Retinal (11-cis)

• β-carotene

• Retinoic acid

In a dark room, Hannah is studying the effects of light on vision. She learns that when light is absorbed by rhodopsin in the retina, it triggers a specific chemical change. What happens to the rhodopsin?

• Conversion of all-trans-retinal to 11-cis-retinal

• Conversion of 11-cis-retinal to all-trans-retinal

• Release of Vitamin A

• Conversion of rhodopsin to opsin + retinoic acid

In a dark room, a photographer named Kai uses a special camera that mimics the function of rhodopsin in the human eye. When he clicks the shutter, the camera's activated rhodopsin (metarhodopsin II) stimulates which G-protein to enhance the image quality?

• Gs

• Gi

• Gt (Transducin)

• Gq

In a dark room, a scientist named Emma is studying the process of phototransduction in the retina. She discovers that the enzyme activated by transducin is crucial for converting light signals into electrical signals. What is the enzyme that Emma identifies?

• Adenylate cyclase

• Phosphodiesterase (PDE)

• Guanylate cyclase

• Protein kinase C

Imagine a dark room where a light sensor is present. When the Na⁺ channels in the sensor close due to the absence of light, what happens to the sensor's response?

• Depolarization

• Hyperpolarization

• No change in membrane potential

• Increased neurotransmitter release

In a fascinating experiment, a scientist named Evelyn is studying the regeneration of 11-cis-retinal from all-trans-retinal. She discovers that this process occurs in the:

• Rod outer segment

• Retinal pigment epithelium (RPE)

• Cone inner segment

• Corneal epithelium

Nora, a biologist studying the visual cycle, is investigating the effects of Vitamin A deficiency on vision. She wonders which step in the visual cycle is primarily affected by this deficiency.

• Light absorption by opsin

• Conversion of 11-cis-retinal to all-trans-retinal

• Regeneration of 11-cis-retinal from retinol

• Activation of transducin

During a routine health check-up, a doctor notices that Nora has been having difficulty seeing in low light conditions. Concerned about her eye health, the doctor asks her about her symptoms. Which symptom is an early sign of Vitamin A deficiency?

• Color blindness

• Night blindness

• Photophobia

• Loss of peripheral vision

In the human eye, the light-sensitive pigment responsible for vision in low light conditions is known as Rhodopsin. Rhodopsin is a combination of:

• Retinal and albumin

• Retinol and opsin

• 11-cis-retinal and opsin

• Retinoic acid and globin

During a biology class, Zoe learned about various genetic mutations and their effects on the human body. She was particularly interested in how certain mutations can affect vision. Her teacher asked the class, "Which of the following genetic mutations is associated with defective phototransduction?"

• Rhodopsin gene

• Hemoglobin gene

• Myosin gene

• Catalase gene