Cellular Biology, Body Tissues, and Human Nutrition

Cell Biology Fundamentals

• Cell Membrane: A thin layer surrounding the cell.
• Cytoplasm: The cellular material excluding the contents of the nucleus.
• Cell Nucleus: A spherical structure which is in the center of the cell.

Cell Organelles

• Mitochondria: They provide energy to the cell.
• Vacuoles: Store products or waste materials.
• Lysosomes: Transform complex substances into simpler ones.
• Cytoskeleton: Is the structural framework (backbone) of the cell.
• Centrioles: Direct the movement of the cytoskeleton.
• Golgi Apparatus: Its function is secretion.

Structure of the Nucleus

• Nuclear Envelope: A double membrane pierced by pores that permit the exchange of substances.
• Nucleoplasm: The contents within the nucleus.
• Chromatin: Very long filaments formed by coiled structures that contain DNA (hereditary genetic information) inside the nucleus.
• Chromosome: In the human body, there are 46 chromosomes.
• Nucleoli: Areas within the nucleus where ribosomes are made.

Cellular Processes

• Catabolism: The process of breaking down complex molecules into simpler ones.
• Cellular Respiration: Uses oxygen to break down organic molecules, providing energy for the cell.
• Anabolism: The process of building complex molecules from simpler ones.

Human Body Tissues

Tissues are specialized cells that constitute a multicellular organism and are not capable of independent life.

• Epithelial Tissue: Found on the outer surface of external and internal body organs.
• Nerve Tissue: Responsible for collecting information from both inside and outside the body.
• Connective Tissue: Distributed throughout the body, performing functions of connection and support.
  • Examples include: Connective tissue proper, Cartilaginous tissue, Bone tissue.
• Muscle Tissue: Responsible for movement in various parts of the body.
  • Skeletal Muscle
  • Cardiac Muscle (found in the heart)
  • Smooth Muscle

Nutrition and Digestion

• Food: Natural or prepared products that provide the substances our cells need to live.
• Nutrient: The simplest components of food that the body uses for energy, growth, and repair.

Digestion Processes

• Mechanical Digestion: Involves grinding, swallowing, and peristaltic movements.
• Chemical Digestion:
  • Mouth: Amylase begins carbohydrate digestion.
  • Stomach: Stores food and mixes it with gastric juice.

Major Food Groups and Functions

• Proteins: Found in meat, fish, eggs, and milk. Primarily for building and repair (plastic function).
• Carbohydrates & Minerals: Found in potatoes and vegetables. Provide energy, regulate body processes, and contribute to structure.
• Vitamins & Mineral Salts: Found in vegetables, fruits. Primarily for regulating body functions.
• Fats & Lipids: Found in grains, sugars, derivatives, oils, and fats. Primarily for energy storage.