Water, Buffer and pH

Water and Its Importance

• Water is the most abundant component of an organism.
• Water's importance for living things lies in its ability to dissolve a wide variety of substances, allowing it to play a crucial role in many biological processes.

Water's Unique Properties

• The bent or V-shape configuration of water molecules (H2O) contributes to its solvent property.
• Water's high surface tension allows it to form droplets on surfaces.
• Water's dielectric property allows it to effectively weaken the attraction between ions of opposite charges.

Water's Biological Significance

• The high heat capacity of water is considered biologically important because it helps regulate an organism's temperature.
• Water's freezing property differs from most other liquids in that it expands as it freezes.

Water Coverage and pH

• Water covers approximately 71% of the Earth's surface.
• pH measures the concentration of hydrogen ions in a solution or medium.

Solubility of Water

• Water readily dissolve ionic solids and polar molecules due to its polar nature.

Unit 1 Overview

• The central focus of Unit 1 is on the biology of cells and organisms.
• Understanding the importance of water and its unique properties is not an objective of this unit.

Respiration Basics

• The electron transport system is responsible for generating energy in the form of ATP during respiration.
• Non-biological organisms such as metal, iron, and plastic cannot carry out respiration.
• The overall purpose of respiration in living organisms is to generate energy from the breakdown of food molecules.

Phases of Respiration

• In the glycolysis phase, food substrates like carbohydrates, fats, and proteins get broken down into glucose or fructose.
• The end product of anaerobic respiration is lactic acid or ethanol and carbon dioxide.
• Aerobic respiration takes place in the mitochondria within a cell.
• Oxygen is the gas that undergoes exchange during the process of respiration.