Biochemical Processes and Health

Normal Biochemical Processes as Basis of Health

• Health is defined as complete physical, mental, and social well-being; not merely the absence of illness.
• Biochemical health refers to optimal rates of intracellular and extracellular reactions critical for organism survival amidst internal and external pressures.
• Maintenance of health requires optimal dietary intake of vitamins, amino acids, fatty acids, minerals, and water; poor nutrition can lead to diseases like atherosclerosis.

Biochemical Basis of Diseases

• Diseases can arise from dysfunctional biochemical processes, not solely from pathogens or pollutants.
• Abnormalities in genes, proteins, and biochemical reactions are often involved in disease manifestations.
• Disturbances in biochemical functions may stem from issues such as nutrient absorption, enzyme deficiencies, genetic disorders, and hormonal imbalances.

Cell Structures and Organelles

• Each organelle has unique enzymes and functions essential for cellular operations.
• Eukaryotic cells, like human and animal cells, possess a nucleus containing DNA; prokaryotic cells, like bacteria, do not.
• Different cell types vary in organelle quantity based on their specific functions (e.g., liver and muscle mitochondria exhibit variations in enzyme presence).

Plasma Membrane Composition

• The plasma membrane forms a lipid bilayer with embedded proteins, comprising predominantly of proteins (55%), phospholipids (25%), cholesterol (13%), and lesser amounts of other lipids and carbohydrates.
• The membrane is described as a fluid mosaic due to the lateral mobility of proteins and lipids.
• Integral proteins span the membrane, functioning as channels, carriers, receptors, and enzymes.
• Peripheral proteins generally attach to integral proteins or the membrane surface, often serving enzymatic roles.

Functions of Key Organelles

• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for cellular delivery.
• Lysosomes: Serve as the digestive system of the cell, breaking down waste and cellular debris.
• Endoplasmic Reticulum: Divided into rough (with ribosomes for protein synthesis) and smooth (lipid synthesis and detoxification).

Cellular Biochemistry

• Water constitutes 70-85% of cell content, acting as a solvent for biochemical reactions.
• Essential ions include potassium, magnesium, phosphate, and others necessary for cellular functions and reactions.
• Proteins are crucial for cell structure and function, representing 10-20% of cell mass.
• Lipid components, primarily phospholipids and cholesterol, are vital for membrane structure and function, constituting about 2% of cell mass.
• Carbohydrates serve nutritional roles, commonly stored as glycogen, with average concentrations around 1-3% of cell mass.

General Overview of Cells

• Cells are the fundamental living units of the body, composed of various types serving distinct functions.
• Approximately 100 trillion cells exist, operating under shared biochemical mechanisms even with diverse structural adaptations.
• Cell structure involves a nucleus and cytoplasm separated by membranes.

Lipids in the Plasma Membrane

• The membrane's composition includes phospholipids, sphingolipids, and cholesterol, contributing to its functionality and integrity.
• Phospholipids feature hydrophilic heads and hydrophobic tails, forming the bilayer that selectively permits the passage of substances.### Membrane Properties
• Fat-soluble substances like oxygen, carbon dioxide, and alcohol easily penetrate cell membranes.
• Sphingolipids, derived from sphingosine, possess both hydrophobic and hydrophilic properties.
• Sphingolipids play roles in protection, signal transmission, and adhesion for extracellular proteins.

Cell Compartments

• Membranes are lipid structures that isolate the contents of cellular compartments.
• The plasma membrane serves as a barrier between the cell and its external environment.
• Organelles like nucleus and mitochondria have membranes that distinguish their internal environments from the cytosol.
• Membrane systems enable collection and concentration of enzymes for specific cellular functions.
• Transporters and receptors regulate the environment and communication for both cells and organelles.

Prokaryotic vs. Eukaryotic Cells

• Prokaryotic Cells

  • Lack a membrane-enclosed nucleus and organelles.
  • Unicellular, smaller, and simpler; examples include Archaea and Bacteria.
  • No membrane-bound organelles; typically feature mesosomes in some bacteria.
  • DNA is circular and located in a nucleoid; ribosomes are present but not membrane-bound.

• Eukaryotic Cells

  • Possess a membrane-enclosed nucleus and various organelles.
  • Multicellular, larger, and more complex; includes animals and humans.
  • Features include nuclear envelope, nucleolus, and chromatin.
  • Membrane-bound organelles include mitochondria, Golgi apparatus, and endoplasmic reticulum.
  • DNA is more linear; ribosomes are present and membrane-bound.

Key Differences

• Cell Size & Complexity
  • Prokaryotes are generally smaller and less complex than eukaryotes.
• Nucleus
  • Prokaryotes lack a nucleus; eukaryotes contain a true nucleus.
• Vacuoles and Cytoskeleton
  • Prokaryotes have no vacuoles or cytoskeleton; eukaryotes do.
• Cell Division
  • Prokaryotes divide through binary fission; eukaryotes use mitosis.

Similarities

• Both types of cells possess a plasma membrane, cytoplasm, and ribosomes.
• Prokaryotic and eukaryotic cells have DNA and RNA, though they differ in structure.
• Both cell types may have a cell wall and flagella, supporting their respective functions.

This quiz explores the critical relationship between biochemical processes and overall health. It highlights how biochemical reactions impact nutrition and preventive medicine, emphasizing the definition of health as complete well-being. Understand how these processes are vital for survival against various challenges.