Chlorophyll,the Substance Responsible for the Green Color of Leaves,has One

question 21

Multiple Choice

Chlorophyll,the substance responsible for the green color of leaves,has one magnesium atom per chlorophyll molecule and contains 2.72% magnesium by mass.What is the molar mass of chlorophyll?

• A) 24.3 g/mol
• B) 20.2 g/mol
• C) 2020 g/mol
• D) 8.94 g/mol
• E) 894 g/mol

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Definitions:

GABA

Gamma-Aminobutyric Acid, an inhibitory neurotransmitter in the central nervous system that plays a key role in reducing neuronal excitability throughout the nervous system.

Receptor Downregulation

A decrease in the number of receptors on the surface of target cells, often in response to high levels of a hormone or neurotransmitter.

Cyclic AMP

A second messenger important in many biological processes, involved in the activation of protein kinases and regulation of the effects of adrenaline and glucagon.

G Proteins

A family of proteins that act as molecular switches inside cells, involved in transmitting signals from stimuli outside the cell.