Essentials of Human Anatomy and Physiology (10th Edition by Elaine N. Marieb), Cells

Cells

The building blocks of all living things

Nucleus

Control center of cell, contains DNA, necessary for cell reproduction.

Nucleoli

One or more may be present in the nucleus, site of ribosome assembly

Plasma Membrane

A fragile, transparent barrier that contains the cell contents and separates them from the surrounding environment.

Cytoplasm

The cellular material outside the nucleus, inside the plasma membrane. The "factory area" of the cell.

Cytosol

Semi-transparent fluid that suspends other elements

Organelles

Metabolic machinery of the cell

Mitochondria

The "powerhouse" organelles that convert the chemical energy stored in food into compounds that are more convenient for the cell to use

Ribosomes

Site of protein synthesis found in two locations: free in cytoplasm, as part of rough ER

Golgi Apparatus

Modifies and packages proteins ("Traffic Director"), produces different types of packages

Lysosomes

Contain enzymes that digest worn out or non-usable materials within the cell

Peroxisomes

Membranous sacs of oxidase enzymes that detoxify harmful substances such as alcohol and formaldehyde and break down free radicals. Replicate by pinching in half

Cytoskeleton

Network of protein structures that extend throughout the cytoplasm

Cilia

Move materials across the cell surface (located in the respiratory system to move mucus)

Passive Transport

Movement of molecules through the plasma membrane according to the dictates of osmosis, diffusion or filtration.

Diffusion

Particles distribute themselves evenly and movement is from high concentration to low or down concentration gradient.

Facilitated Diffusion

Transports lipid-insoluble and large substances through a cell membrane along a concentration gradient with the aid of carrier proteins.

Active Transport (ATP)

Substances are transported that are unable to pass by diffusion because they are too large, not be able to dissolve in the fat core of the membrane, or have to move against a concentration gradient.

Exocytosis

Active transport process by which a substance is released from the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out.

Endocytosis

Active transport process where a cell engulfs materials with a portion of the cell's plasma membrane and releases the contents inside of the cell.

Phagocytosis

Cellular "eating"; a type of endocytosis whereby a cell engulfs macromolecules, other cells, or particles into its cytoplasm.

Pinocytosis

A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.

Selective Permeability

Plasma membrane allows some materials to pass while excluding others; influences movement into and out of the cell

Cytosol

The aqueous part of the cytoplasm within which various particles and organelles are suspendedq

Organelles

A tiny cell structure that carries out a specific function within the cell.

Mitochondria

The rod-like cytoplasmic organelles responsible for ATP generation.

Ribosomes

Organelles at which proteins are synthesized.

Rough ER

Covered in ribosomes and is responsible for the synthesis and transport of proteins and glycoproteins.

Transport Vesicle

A tiny membranous sac in a cell's cytoplasm carrying molecules produced by the cell.

Smooth ER

Is ER that does not have ribosomes attached. It is a major site of lipid synthesis.

Concentration Gradient

A region along which the density of a chemical substance increases or decreases.

Receptor-Mediated

When a specific molecule binds to its specific receptor.