Primary Components of Human Cells

Practice vocabulary flashcards covering the descriptions and functions of primary cell components and organelles.

Cilia

Short, hair-like microtubules projecting from the cell membrane that aid in the movement of substances along the surface of the cell.

Flagella

Long, hair-like microtubules projecting from the cell membrane that move the cell itself through a whip-like motion.

Golgi apparatus

The "packaging and shipping plant" of the cell comprised of four to six flat membranous sacs connected to the endoplasmic reticulum that packages and releases materials for external use and forms lysosomes.

Lysosomes

Sacs created by the Golgi apparatus that digest waste materials including damaged materials found in the cell, old cell components, and materials entering the cell.

Cytoskeleton

Components comprised of protein microfilaments and microtubules that maintain the shape and structure of the cell while keeping organelles in place and moving them throughout the cell.

Centrioles

A pair of rod-shaped bodies made of microtubules found near the nucleus that participate in cell reproduction through the distribution of DNA to new cells.

Nucleolus

A dark, dense body within the nucleus without an enclosing membrane that forms RNA and ribosomes; most cells contain between one and four.

Mitochondria

Elongated, rod-shaped bodies filled with fluid and containing DNA, known as the "power plant" of the cell because they convert nutrients into energy and create adenosine triphosphate (ATP).

Ribosomes

Small granules of RNA found in the nucleolus or cytoplasm that perform protein synthesis for both internal and external use.

Endoplasmic reticulum

A complex connection of membranous fluid-filled, flat sacs and tubular channels that connects the cell membrane to the nucleus membrane and transports materials throughout the cell.

Rough endoplasmic reticulum (RER)

A portion of the endoplasmic reticulum that supports the synthesis and transport of proteins.

Smooth endoplasmic reticulum (SER)

A portion of the endoplasmic reticulum that supports the synthesis of some lipid molecules, including steroids.

Plasma membrane

A selectively permeable membrane made of phospholipids and proteins that surrounds the entire cell and separates the internal components from the surrounding environment.

Cytoplasm

A gel-like fluid primarily comprised of water with electrolytes, metabolic waste products, and nutrients dissolved within it that serves as a medium for chemical reactions.

Nucleus

A large, spherical body near the center of the cell that acts as the control center, regulates cell activity, and houses genetic material in the form of DNA.

Nuclear membrane

A double-layered, porous membrane surrounding the nucleus that protects it and allows only specific materials to enter.