In a signal transduction pathway, fine tuning of the cellular response occurs in several steps. Which of the following best describes how the response would be affected if the molecular changes that occur during a signaling pathway lasted for a prolonged period? Inactivation mechanisms would be triggered before the pathway could be completed.
Receptors would be unable to return to their inactive form and respond to new signals.
Scaffolding proteins would cause potentially harmful signal amplification in the cytosol.
Signaling proteins would be unable to take part in multiple pathways, as specificity is lost.

Receptors would be unable to return to their inactive form and respond to new signals.

Explanation:

Many signaling pathway involves the regulation of the protein synthesis. It involves the turning off or on of some of the specific genes present in the nucleus. If the receptors become unable to resume to the inactive form the may not be able to produce  new signals during protein synthesis. The final activated molecule in a signal pathway may not function as transcription factor.

both anaerobic and aerobic respiration use glucose (or other carbohydrates), proteins and lipids to produce atp and nadh. cell uses those energy molecules, obtained from food and   breaks them down during the chemical reactions of respiration. in anaerobic respiration, nadh is regenerated to nad+ by enzymes lactate dehydrogenase (lactate is produced, e.g. in muscle cells) or by alcohol dehydrogenase where ethanol is produced (alcohol fermentation), while in aerobic respiration, electrons from nadh are deposited in the mitochondria to regenerate nad+ (electron transport chain. anaerobic respiration produces 2 atp per molecule of glucose compared to aerobic respiration where about 38 atp molecules are produced.

is in the form atp or adenosine triphosphate