Question

The process of enzymatically breaking down large molecules into smaller molecules that can be used by cells is a. absorption. b. secretion. c. ingestion. d. digestion. e. egestion.

Short answer

d. Digestion

Step-by-step solution

Understanding the Question

The question asks about the process in which large molecules are broken down into smaller ones that can be used by cells. Therefore, a term that essentially represents this biological process is required.

Analyzing the Options

Each term is evaluated as follows:- Absorption represents the uptaking or receiving of substances (material or light, for example) and is not specifically about breaking down large molecules.- Secretion is the process through which substances are produced and discharged from a cell or organ, which is also not the process in question.- Ingestion is the process of taking in food through the mouth, typically related to multi-cellular organisms, and thus, not the exact process being asked about.- Digestion is the breakdown of food (e.g., large organic molecules) in the body into smaller ones for easier absorption; thus, this term is the closest to the process in question.- Egestion is the act of excreting undigested waste, which is not related to breaking down molecules for absorption.

Choosing the Correct Answer

Given the analysis of each term, the process by which large molecules are enzymatically broken down into smaller ones that can be used by cells is digestion.

Key concepts

Enzymatic breakdown

Enzymatic breakdown is a crucial part of the digestive process. It involves the use of enzymes, which are special proteins that accelerate chemical reactions. These enzymes are responsible for breaking down complex food molecules into simpler substances that our bodies can use.

• Enzymes are specific: Each type of enzyme targets a specific nutrient. For example, amylase breaks down carbohydrates, while proteases target proteins.
• Reaction time: The presence of enzymes ensures that these reactions happen quickly enough to support bodily functions.

Without enzymes, our bodies would not be able to efficiently process food into energy and nutrients. This enzymatic activity is vital as it initiates the many steps involved in the digestive process.

Large molecules

In the context of digestion, large molecules refer predominantly to the components of the food we eat. These include carbohydrates, proteins, and fats. Before our bodies can absorb these nutrients, they need to be broken down into smaller, usable pieces.

• Carbohydrates: Initially present as complex chains (starch), these are broken down to simple sugars like glucose.
• Proteins: Composed of long chains of amino acids, these are simplified into individual amino acids.
• Fats: Big molecules composed of fatty acids and glycerol. They are reduced to allow absorption into cells.

The breakdown of these large molecules is essential for nutrition, as it allows the nutrients to be absorbed into the bloodstream and utilized by the body.

Absorption

Absorption in the digestive process refers to how digested food enters the bloodstream from the intestinal tract. Once large molecules are broken down into their smaller counterparts through enzymatic processes, they are ready for absorption.
Here’s how it happens:

• Villi and Microvilli: These are tiny, finger-like structures within the intestines that greatly increase the surface area for absorption, making it easier for nutrients to enter the blood.
• Simple diffusion, facilitated diffusion, and active transport: These are mechanisms by which nutrients pass through the intestinal walls into the blood.

The effective absorption of nutrients is critical for maintaining energy levels and overall health, as it allows every cell in the body to function optimally.

Biological process

Digestion is an intricate biological process that supports life by breaking down food into forms that are utilized by the body. It involves several organs and mechanisms working together systematically.

• Mechanical breakdown starts with chewing in the mouth, where food is physically made smaller.
• Chemical breakdown follows, with enzymes being secreted in the stomach and intestines to dismantle large molecules.
• The entire system - from ingestion to excretion - ensures that nutrients are absorbed and waste products are eliminated, keeping the body healthy and balanced.

Understanding digestion as a biological process highlights its complexity and underscores the interplay between different systems to sustain life.