BackChapter 2: Chemistry Comes Alive – Basic Chemistry for Biology
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Chapter 2: Chemistry Comes Alive
Introduction to Chemistry in Biology
Chemistry is fundamental to understanding physiological processes in living organisms. All biological functions, from movement to digestion, are driven by chemical reactions. This chapter introduces the basic chemical principles essential for biology students.
Biological systems are composed of many chemicals.
Chemistry underlies all physiological reactions, such as movement, digestion, heart function, and nervous system activity.
Chemistry can be divided into basic chemistry (the study of matter and energy) and biochemistry (the chemistry of living organisms).
Matter and Its States
Definition and Properties of Matter
Matter is anything that has mass and occupies space. It is the physical substance of the universe and can be detected by our senses.
Mass is the amount of matter in an object, while weight is mass plus the effects of gravity.
Matter can exist in three states:
Solid: Definite shape and volume (e.g., bones).
Liquid: Changeable shape, definite volume (e.g., blood plasma).
Gas: Changeable shape and volume (e.g., oxygen in the lungs).
Energy in Biological Systems
Definition and Forms of Energy
Energy is the capacity to do work or put matter into motion. Unlike matter, energy does not have mass or occupy space, but it is essential for all biological activities.
The more work done, the more energy is used.
Energy exists in two main forms:
Kinetic energy: Energy in action (e.g., muscle contraction).
Potential energy: Stored energy (e.g., energy stored in chemical bonds).
Energy can be transformed from potential to kinetic and vice versa.
Types of Energy Important in Biology
Chemical energy: Stored in the bonds of chemical substances (e.g., ATP).
Electrical energy: Results from movement of charged particles (e.g., nerve impulses).
Mechanical energy: Directly involved in moving matter (e.g., muscle movement).
Radiant (electromagnetic) energy: Travels in waves (e.g., visible light, UV light).
Energy conversions are never 100% efficient; some energy is always lost as heat or sound, making it partly unusable.
Summary Table: States of Matter
State | Shape | Volume | Example in Biology |
|---|---|---|---|
Solid | Definite | Definite | Bones |
Liquid | Changeable | Definite | Blood plasma |
Gas | Changeable | Changeable | Oxygen in lungs |
Key Terms and Concepts
Matter: Anything that has mass and occupies space.
Mass: The amount of matter in an object.
Weight: Mass plus the effects of gravity.
Energy: The capacity to do work or put matter into motion.
Kinetic energy: Energy of motion.
Potential energy: Stored energy.
Example: Energy Transformation in Muscle Contraction
Chemical energy stored in ATP is converted to mechanical energy during muscle contraction, with some energy lost as heat.
Additional info: These foundational concepts in chemistry are essential for understanding more complex biological processes, such as metabolism, cellular respiration, and homeostasis.
