A Biologist Discovers a New Signal Transduction Pathway in Fruit

question 149

Multiple Choice

A biologist discovers a new signal transduction pathway in fruit flies that involves a protein kinase cascade.As part of a grant proposal he writes to obtain funding for further work on this pathway, the biologist proposes research to look for phosphatase enzymes.Why?

• A) Since a signaling cascade contains multiple enzyme-catalyzed events, the biologist needs to identify all of the enzymes participating in the cascade.
• B) Since a phosphatase enzyme catalyzes the removal of phosphate ion from a substrate, the biologist needs to be sure that none are interfering with the signaling cascade.
• C) The biologist needs to identify the enzymes that provide the source of phosphate ions added to substrates during the signaling cascade.
• D) The biologist needs to identify the enzymes that regulate the pathway by removing phosphate groups from molecules in the signaling cascade.
• E) The biologist needs to identify all enzymes involved in phosphate ion transfer to determine whether they are involved in the pathway.

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Definitions:

Accommodation

In optics, the ability of the eye to change its focal length to focus on objects at various distances, or the process of adjusting to something new.

Presbyopia

A condition associated with aging in which the eye's lens loses its ability to focus on close objects, resulting in difficulty with near vision.

Myopia

A common vision condition also known as nearsightedness, where distant objects appear blurry while close objects can be seen clearly.

Visual Pathway

The route taken by light signals converted into neural signals from the retina through various brain regions, culminating in visual perception in the occipital lobe.