Cell Organelles and Food Preservation Techniques

Cell Organelles

Mitochondria: Oval-shaped organelles with two membranes. Through cellular respiration, mitochondria produce energy for the cell.

Vesicles: Small, rounded organelles that store, transport, or digest cellular substances. Lysosomes are rounded vesicles produced by the Golgi body.

Endoplasmic Reticulum: A network of interconnected membranous sacs and channels. There are two types:

• Rough ER: Connected with the nuclear envelope and ribosomes.
• Smooth ER: This type has no attached ribosomes.

Golgi Body: Flat, membranous sacs arranged in layers. Secretory vesicles transport substances out of the cell.

Centrosome: Consists of two centrioles: perpendicular cylindrical structures composed of microtubules. They are surrounded by other microtubules that form the aster. Centrosomes participate in the organization of the cytoskeleton, cell movement, and formation of the mitotic spindle when the cell divides.

Ribosomes: Non-membranous particles found in the cytoplasm or attached to the ER. Involved in protein synthesis.

Cytoskeleton: Made of protein filaments, it maintains the shape of the cell, organelles, and internal vesicles. It is also involved in chromosome organization.

Building Blocks, Energy Producers, and Body Regulators

These categories describe the roles of different nutrients in the body:

• Building Blocks: Provide the materials for cells, tissues, and organs. They are needed for growth and repair or to replace damaged structures. They are high in proteins and minerals.
• Energy Producers: Produce energy to be used immediately or stored for later use. They are high in proteins and minerals.
• Body Regulators: Provide essential substances that regulate the use of other foods and enable the body to carry out its functions. They are high in vitamins, minerals, fiber, and water.

Nutrient Groups:

• Yellow Group (Groups 1 and 2): Energy producers.
• Red Group (Groups 3 and 4): Build body structures.
• Green Group (Groups 5 and 6): Body regulators.

Food Preservation Techniques

Cooling and Freezing

• Refrigeration: Above 0°C (32°F). Slows the growth of microorganisms.
• Freezing: Below 0°C (32°F). Stops the growth of most microorganisms.

Heating

• Pasteurization: Heated to under 100°C (212°F) for 15 seconds. Kills most pathogenic microorganisms.
• Ultra-Pasteurization: Uses a higher heat than pasteurization but for less time.
• Sterilization: Heated above 100°C (212°F) for a set amount of time. Kills all microorganisms.

Other Methods

• Dehydration: Reduces or eliminates water from food, reducing food weight and volume and preventing the growth of microorganisms.
• Chemical Preservation: Substances are added to prevent the growth of microorganisms. Sugar is used in jams, salt is used in meat and fish. Sometimes artificial additives and preservatives are added to food.