Cell Biology and Nutrition Essentials
ITEM 1 Cell Parties
Mitochondria
Oval organelles that provide energy.
Reticulum
Sacks and interconnected channels where proteins and lipids are produced.
Vacuoles
Contain water and dissolved substances.
Lysosomes
Transform substances into simpler ones.
Cytoskeleton
Complex filaments forming a network.
Centrioles
Two hollow cylinders with walls formed by filaments.
Ribosomes
Small particles, free or attached, that manufacture proteins.
Golgi Apparatus
Stacks of membranous sacs that package substances manufactured in the reticulum; main function: secretion.
Nucleus
Nuclear Envelope
A double membrane pierced by pores, allowing substance exchange between nucleus and cytoplasm.
Nucleoplasm
Content of the nucleus, formed by solutions.
Chromatin
Long strands acting together, formed by DNA molecules inside the nucleus.
Nucleoli
Core areas where ribosomes are built, spherical in form.
Membrane
Diffusion
Mechanism by which substances traverse the plasma membrane.
Osmosis
Diffusion of water from a dilute solvent to a more concentrated one.
Active Transport
Active transport occurs in the cell where substances are needed in less concentration, transported through a membrane against the diffusion process.
Cell Metabolism
Cell metabolism is a set of chemical reactions occurring within the cell.
- Catabolism: Reactions whose objective is to degrade complex molecules into simpler ones to release energy.
- Anabolism: Reactions whose goal is to build complex molecules from simpler ones.
Tissue Types
- Connective Tissue: Fills the body, deeper layer of skin, cartilage occupies space between organs.
- Bone Tissue: Principal component of the skeleton, found in joints and bones, firm consistency.
- Striated Skeletal Muscle Tissue: Forms muscles attached to bones, producing movement; voluntary contraction.
- Cardiac Tissue: Thick walls of the heart; involuntary contraction.
- Smooth Muscle Tissue: Found in the stomach wall, blood vessels, bladder, uterus; involuntary contraction.
UNIT 2 Inorganic Substances
Water
The most abundant compound, the living environment in which life develops in cells.
Mineral Salts
Found in bones and teeth, providing consistency; also dissolved in all body fluids.
Organic Substances
- Carbohydrates: The simplest, like glucose, are sweet and known as sugars.
- Lipids: Fats, dissolved little or not at all in water; unsaturated in plants and saturated in animals.
- Proteins: Formed by the union of thousands of simple molecules, e.g., hemoglobin.
- Vitamins: Substances needed in very small quantities but essential for the proper functioning of the body.
Digestion
Mechanical
- Grinding: Performed by teeth in the mouth.
- Swallowing: Passage of food from the mouth to the esophagus.
- Movements: Caused by muscle contractions in the digestive tube wall.
Chemical
Occurs in the mouth where saliva begins the digestion of carbohydrates. In the stomach, food is stored and mixed with gastric juice produced by glands in the wall. In the small intestine, the process is completed; juices are poured into the duodenum to break down fats and complete the formation of carbohydrates.
Intestinal Absorption
The passage of nutrients from the digestive tract into the blood occurs in the intestine.
Food Function
- Plastic Function: To build our own structures and replace lost materials (function by protein-rich foods).
- Energy Function: Release energy to enable muscle work or maintain body temperature (carbohydrates).
- Regulatory Function: Enable all body processes to occur normally (mineral salts and vitamins).
Genetically Engineered Foods
Foods into which genetic information from another living being has been introduced to exhibit a characteristic of that being.