In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.

Question: Indicate the amino acid that, under physiological conditions, has an uncharged side chain: 
 Options:  <1> Arginine <2> Aspartic acid. <3> Glutamic acid. <4> Lysine <5> Threonine
5

Question: Among the epidemiological criteria of causality defined by Bradford Hill (1965) is NOT: 
 Options:  <1> Strength of association. <2> Temporal sequence. <3> Biological gradient <4> Cessation or reversibility effect. <5> Presence of alternative explanations.
5

Question: Which of the following metabolites is a gluconeogenic substrate: 
 Options:  <1> Ethanol. <2> Oleic acid. <3> Acetyl-CoA. <4> NADPH + H +. <5> Glycerol.

5