Question

Your body creates chemical energy from the food you eat, which contains sugars, carbohydrates, and proteins. These are large molecules that first need to be broken down into simpler molecules, such as monosaccharides, \(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\), fatty acids, \(\mathrm{C}_{14} \mathrm{H}_{28} \mathrm{O}_{2}\), and amino acids, \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{NO}_{2}\). Of these molecules, which has the greatest supply of hydrogens? Which is the most reduced? Which can react with the most oxygen molecules to produce the most energy? Which provides the most dietary Calories per gram?

Short answer

Fatty acid: most hydrogens, reacts with the most oxygen, gives the most Calories. Amino acid: most reduced.

Step-by-step solution

Identify the Number of Hydrogens

First, let's determine the number of hydrogen atoms in each molecule given: - Monosaccharide (\(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\)): 12 hydrogens. - Fatty acid (\(\mathrm{C}_{14} \mathrm{H}_{28} \mathrm{O}_{2}\)): 28 hydrogens. - Amino acid (\(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{NO}_{2}\)): 5 hydrogens.The fatty acid has the greatest supply of hydrogens with a total of 28.

Compare the Reduction Levels

A molecule with more hydrogen atoms per carbon is generally more reduced. - Monosaccharide: 12 hydrogens over 6 carbons (ratio: 2). - Fatty acid: 28 hydrogens over 14 carbons (ratio: 2). - Amino acid: 5 hydrogens over 2 carbons (ratio: 2.5). The amino acid is the most reduced since it has the highest ratio of hydrogens per carbon.

Determine Reaction with Oxygen

The molecule that can react with the most oxygen to produce the most energy is typically the most energetically efficient. Typically, the combustion of more reduced molecules (those with more hydrogens) results in more energy. The fatty acid, with more total hydrogens, reacts with more oxygen, leading to more energy production.

Calculate Dietary Calories

Fatty acids contain more hydrogen and carbon atoms per gram compared to carbohydrates and proteins, which means they yield more Calories per gram. Therefore, the fatty acid will provide the most dietary Calories.

Key concepts

Macronutrient Breakdown

Our bodies rely on a fascinating process called macronutrient breakdown to convert the food we eat into useable energy. Food contains macronutrients such as carbohydrates, proteins, and fats. These are complex molecules that need to be broken down into simpler forms before being used for energy. For instance, carbohydrates break down into monosaccharides like glucose (\( \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6} \)), fats break down into fatty acids like (\(\mathrm{C}_{14} \mathrm{H}_{28} \mathrm{O}_{2}\)), and proteins become amino acids such as (\(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{NO}_{2}\)).
This breakdown involves enzymatic actions that transform complex molecules into simpler, absorbable units. Each macronutrient type requires specific enzymes for its breakdown. Understanding this process is crucial for comprehending how our bodies harness energy from food.

Molecular Reduction

Molecular reduction is a concept in chemistry where a molecule gains electrons, often accompanied by the gain of hydrogen atoms. This process is significant in metabolism because reduced molecules tend to hold more potential energy.
In our context, a molecule's "hydrogen per carbon" ratio indicates its reduction level.

• Monosaccharide: 12 hydrogens/6 carbons = 2
• Fatty acid: 28 hydrogens/14 carbons = 2
• Amino acid: 5 hydrogens/2 carbons = 2.5

These ratios show how the amino acid is the most reduced molecule among the three, providing it with a high electron density.
This higher ratio means, theoretically, the amino acid harbors more stored energy per carbon when compared to the others.

Caloric Energy

Caloric energy refers to the energy a food provides to the body and is usually measured in calories or kilocalories. The energy is determined by how many potential bonds can be broken and converted into energy.
Fatty acids, with their larger number of hydrogen and carbon atoms, offer more breakable bonds per gram than carbohydrates and proteins.
Thus, when fatty acids undergo oxidation, they release more energy, making them the richest energy source in terms of calories. This is critical to know for diets and energy management, as different macronutrients provide different levels of energy.

Dietary Chemistry

Dietary chemistry is the science that examines the chemical processes and interactions related to the food we consume. It helps us understand how food provides us with the nutrients and energy needed for survival.
Foods are made up of molecules which in turn are composed of elements like carbon, hydrogen, oxygen, nitrogen, and more.
By studying dietary chemistry, we learn how various nutrients behave in the body, how much energy they supply, and what forms they take to be usable. This knowledge helps individuals make informed dietary choices aligned with their nutritional needs and lifestyle goals, complementing overall health.