Final answer:
True, alcohol can enter cells without needing digestion due to its small, lipid-soluble nature. Likewise, glucose doesn't require digestion and can be directly absorbed. Digestion involves the conversion of complex foods to simpler forms, with absorption being the final step in the digestive process.
Step-by-step explanation:
The statement "Alcohol requires no digestion and can enter cells without specific transport mechanisms" is true. Alcohol is a small, lipid-soluble molecule that can easily diffuse through the cell membrane of the digestive epithelium into the bloodstream. This characteristic allows alcohol to be absorbed into the body's system quickly, bypassing the need for the digestive enzymes and transport mechanisms typically required for nutrient absorption.
Similarly, glucose can be absorbed by the body without being further broken down. Glucose is a simple sugar and doesn't require digestion to be utilized by the body's cells as it is already in its simplest form, ready for absorption into the bloodstream from the digestive tract.
Digestion typically involves the breakdown of complex food substances into simpler forms that can be absorbed and utilized by the body. While some chemical digestion occurs in the mouth through enzymes like amylase, others like pepsin, which is found in the stomach, specifically break down proteins but not cellulose. It's significant to note that humans are unable to digest cellulose because they lack the enzyme cellulase. As a result, cellulose remains undigested and is excreted as waste.
The pH of the stomach is highly acidic, usually around 2, to facilitate the activity of digestive enzymes like pepsin and to kill pathogenic microbes in ingested food. In contrast, absorption is the last step of the digestive process, which occurs after the food has been mechanically and chemically broken down to its simplest form, primarily in the small intestine.