Plasma Membrane
Forms boundary between extracellular and intracellular spaces, controls substance movement into and out of cells. Keeps cell whole. Contains receptors on the surface. Phospholipid bilayer.
Cytoplasm
The main interior substance of the cell. Supports cell membrane. Allows movement of intracellular molecules and organelles.
Cytoskeleton
Microtubules and filaments provide strength, structure, and support for the cell. Maintains cells shape. Supports intracellular movement of organelles.
Nuclear Membrane
Membrane around the nucleus. Additional layer of protection for genetic material. Controls substance movement into and out of the nucleus. Phospholipid bilayer.
Nucleus
Controls cell activity. Contains DNA in chromosomes. Location of transcription of DNA into RNA. DNA is the basis for heredity.
Chromatin
Clusters of expanded DNA and proteins. Involved in DNA repair, preventing DNA entanglement, and dividing chromosomes in mitosis and meiosis.
Nucleolus
Clusters of RNA and proteins inside the nucleus. Subunits of ribosomes are synthesized here before they are released. Making ribosomes.
Centriole
A pair of barrel like cylinders in the center of the nucleus. Produce asters and anchor spindle fibers. Duplicate and move to opposite side of nucleus to separate DNA strands during mitosis. Aid in cell division.
Ribosomes
Granules of RNA and proteins. Synthesized in the nucleus. Functional ribosomes are located free in the cytoplasm or attached to the endoplasmic reticulum. Translate RNA into proteins. Two part proteins - take mRNA and print proteins.
Endoplasmic Reticulum
Network of extremely small, extremely thin walled canals extending from the nuclear membrane.
Smooth ER
Produces and packages lipids and carbohydrates.
Rough ER
Has ribosomes attached for protein production and packaging.
Golgi Complex
Tiny sacs stacked one upon the other near the nucleus. Makes certain carbohydrates, combines them with certain protein molecules, and packages products in vesicles. These vesicles carry the contents to various locations in the cell, and can merge with the cell membrane to spill the contents to the outside of the cell.
Lysosomes
Special lysosomes created by the Golgi apparatus. Contain powerful enzymes. Envelop foreign material or debris in the cytoplasm. Enzymes disintegrate the absorbed debris. Digested contents are ejected from the cell.
Mitochondria
Sausage shaped structure. Consists of two membrane sacs, one inside the other. Site of cellular respiration (metabolism), which provides energy (ATP) for the cell. Oxidative phosphorylation. POWER HOUSE OF THE CELL
Catabolism
Process by which cells gain energy from foods. Breakdown of complex molecules into smaller ones, destructive metabolism. Releases energy for use.
Anabolism
Process by which cells make complex compounds out of simpler compounds. Synthesis of complex molecules out of simpler ones, constructive metabolism. Used to store energy for future use.
Vacuoles/Pinocytotic Vesicles
Membrane lined containers within the cytoplasm. Typically contain fluid. Eject contents from the cell or engulf and bring in extracellular substances.
Phagocytosis
Cellular eating
Pinocytosis
Cellular drinking
Cell Physiology
Study of activities occurring in a cell to keep it alive.
Diffusion
Molecules move from an area of greater concentration to an area of lesser concentration. Requires a permeable barrier.
Osmosis
Diffusion of water through a semi-permeable membrane. Water moves from less dense solution to more dense solution.
Active Transport
Movement of materials across cell membranes and epithelial layers requiring energy expenditure.
Passive Transport
Movement of materials across cell membranes and epithelial layers not requiring energy expenditure.
Cellular Reproduction
Living things must be able to reproduce themselves. Somatic (body) cells reproduce by a process called mitosis. Some cells produce regularly and frequently (epithelial cells) and others only under certain circumstances (nerve). Germ (sex) cells reproduce by a process called meiosis. Cancer is uncontrolled mitosis.
Atrophy
Is failure of certain cells to grow and divide.