One of the key differences between homeostasis and metabolism is that homeostasis refers to the ability to maintain a stable and constant internal environment within the body regardless of the changes in the external environment while metabolism refers to the set of chemical reactions that occurs within an organism.
All organisms share certain fundamental properties such as cellular organization, sensitivity, growth, development, reproduction, regulation, and homeostasis. These properties basically put the foundation to life on Earth. Homeostasis and metabolism are two major processes an organism must maintain during its lifetime. Without these processes, the organisms would not have survived.
CONTENTS
1. Overview and Key Difference
2. What is Homeostasis
3. What is Metabolism
4. Similarities Between Homeostasis and Metabolism
5. Side by Side Comparison – Homeostasis vs Metabolism in Tabular Form
6. Summary
What is Homeostasis?
Generally, all living organisms must maintain constant internal body conditions regardless of the changing environmental conditions. Homeostasis is this ability of an organism to adjust itself to restrain the external changes and maintain the dynamic constant state of functioning within the body. Therefore, homeostasis is essential for life. It maintains most regulatory mechanisms of many advanced organisms (vertebrates) such as heart rate, breathing rate, blood glucose levels, fluid levels, and body temperatures, etc. The advantage of homeostasis is that it allows organisms to survive and function efficiently and effectively in a broad range of environmental conditions.
Figure 01: Calcium Homeostasis
In many organisms, the nervous system controls the homeostasis via nerve impulses. Maintenance of homeostasis involves negative feedback loops that work towards set points of the body. For example, when the body temperature goes up, the negative feedback loop brings the body temperature towards the setpoint 37 0C, which is the normal body temperature. Likewise, homeostasis maintains a relatively constant and stable environment within the organism’s body. However, something that interferes negative feedback loops can disrupt homeostasis. One such condition is diabetes that occurs due to the inability of the pancreas to produce insulin hormone.
What is Metabolism?
Metabolism is the set of all chemical reactions that occur in an organism. In simple words, it refers to the set of life-sustaining chemical reactions in an organism. Organisms need energy for many of their actions such as moving, breathing, thinking, blood circulation, eating, singing, etc. To produce energy, the body cells convert the fuel (food) into energy by chemical reactions. Some specific proteins in the body control these chemical reactions, and certain body functions coordinate these reactions.
Figure 02: Metabolism
There are two types of metabolisms as catabolism and anabolism. Catabolism refers to the set of metabolic pathways that break down organic matter into small molecules. Anabolism, on the other hand, refers to the set of metabolic pathways that construct organic molecules such as proteins, lipids, nucleic acids, etc. from their building blocks. All these chemical reactions occur using a sequence of enzymes. Likewise, one chemical transforms into another chemical with a series of reaction steps organized into metabolic pathways. Enzymes play a vital role in metabolism since they regulate the rate of the reaction. More importantly, enzymes increase the rate of biochemical reactions and allow the reactions to proceed quickly and efficiently.
What are the Similarities Between Homeostasis and Metabolism?
- Homeostasis is required for metabolism.
- Both homeostasis and metabolism occur via a series of reactions.
- Also, both take place in living organisms.
What are the Differences Between Homeostasis and Metabolism?
Homeostasis is the ability to maintain the internal system of an organism in a dynamic constant functioning state. In contrast, metabolism is the collection of all chemical reaction carried out in an organism. Therefore, we can consider this as the key difference between homeostasis and metabolism. Furthermore, there are more differences between homeostasis and metabolism.
Unlike homeostasis, metabolism can be divided into two categories as anabolism and catabolism. Due to the metabolism of the body, certain internal properties (internal body temperature, pH etc.) could be changed. In contrast, regulating and keeping these properties in constant level is done by the homeostasis. So, this is also a significant difference between homeostasis and metabolism. Also, normally, hormones are involved in controlling homeostatic regulations while enzymes are involved as catalysis, and they control metabolic pathways. Thus, we can take this also as a difference between homeostasis and metabolism.
Moreover, specific proteins in the body control the metabolic reactions while the nervous system controls the homeostatic regulations. Besides, the metabolic rate can be decreased or increased by homeostasis regulation mechanisms, but homeostasis cannot be controlled by metabolism. Thus, these are some important differences between homeostasis and metabolism.
Summary – Homeostasis vs Metabolism
Homeostasis is the tendency to maintain a stable, relatively constant internal environment inside the body. On the contrary, metabolism is the collection of all chemical reactions occurring in an organism. Homeostasis is necessary for metabolism. But metabolism cannot control homeostasis. Furthermore, enzymes control metabolism while the nervous system controls homeostasis. This is a summary of the differences between homeostasis and metabolism.
Reference:
1. “Homeostasis.” Khan Academy, Khan Academy, Available here.
2. “Metabolism.” Wikipedia, Wikimedia Foundation, 20 Feb. 2019, Available here.
Image Courtesy:
1. “625 Calcium Homeostasis” By Anatomy & Physiology, Connexions Web site, Jun 19, 2013. – OpenStax College (CC BY 3.0) via Commons Wikimedia
2. “Human Metabolism – Pathways” By Evans Love – Own work (CC BY-SA 4.0) via Commons Wikimedia