Biochemistry and Biophysics: Fundamentals of Life’s Chemistry
Biochemistry and Biophysics: The Chemistry of Life
Biochemistry and biophysics are the sciences that deal with the basic chemistry of life. The objective is to study the chemical composition of living beings, the relationships between their chemical compounds, their transformations, regulation, and how these transformations have repercussions in the field of physiology of organisms.
Bioelements and Biomolecules
Bioelements are distinguished as primary, secondary, and trace. They combine to form organic molecules or biomolecules of life, which are the fundamental units in cells and perform different functions. Organic molecules can be defined as those molecules that contain carbon. This topic is about organic molecules found in living organisms. Of the different molecules that can be found in a living system, water constitutes between 50 and 95%.
General Concept of Metabolism
The totality of the chemical reactions that take place in a cell make up its metabolism. Metabolic reactions occur in series, called pathways, where the product of a reaction becomes the substrate of the next, and each serves a specific function in the cell. In addition, these reactions occur in a particular compartment of the cell, and there is control over those reactions. Each step in a pathway is controlled by a specific enzyme.
Homeostasis: Maintaining Stability
Homeostasis refers to all coordinated physiological processes through which the body maintains a steady state against internal or external changes that may occur. The maintenance of stability, i.e., homeostasis, is very important because it allows all the metabolic processes of the organism to occur. There are two ways to maintain homeostasis: through changes that can be predicted and changes that cannot be predicted or are unexpected.
Water: Structure and Properties
Water, the most common liquid on Earth’s surface and the main component by weight of all living beings, has a number of remarkable properties. Water forms an electric dipole structure. The importance of this biomolecule in this study lies in the fact that nearly all biochemical reactions in the body take place in aqueous conditions.
Physicochemical Properties of Water
- Water is liquid within a range of temperatures (0-100 °C).
- Water presents maximum density at 4 °C.
- Water has a high dielectric constant.
- Water is a dipole.
- Water has a high specific heat (1 cal/°C x g = heat needed to raise the temperature of 1g of water by 1 °C).
- Water has a very high heat of vaporization (amount of heat required to evaporate a gram of water: 0.536 cal/g).
- Water is characterized by high surface tension.
- Water dissociates as a weak electrolyte.
Dissociation reaction of water.
Osmotic Pressure: Concept and Biological Importance
In a dilution, two separate components are called solute and solvent. The incorporation of a solute into a solvent to form a solution causes some of the solvent’s properties to be modified. Osmotic pressure, or tonicity of the solution, has great significance because the extracellular fluid compartment should have the same values as the intracellular environment, i.e., both should be isotonic, because there is no net movement of water in either of two directions that endanger cell survival.
Distribution of Water and Water Balance
The volume of liquid in each compartment depends on the amount of osmotically active substances present. It is regulated by increasing or decreasing this content. The maintenance of these aqueous volumes (water balance) is necessary for the organism to be able to fully develop its vital functions.