Cell Structures Flashcards
What is the plasma membrane (PLAZ-mah)
The outer layer of the cell, composed mainly of lipids and proteins.
What is the function of the plasma membrane?
It encloses the cell contents; regulates what enters and leaves the cell; participates in many activities, such as growth, reproduction, and interactions between cells.
What are microvilli (mi-kro-VIL-i)?
Short extensions of the cell membrane
What is the function of microvilli?
They absorb materials into the cell
What is the nucleus (NU-kle-us)?
The large, membrane-bound, dark-staining organelle near the center of the cell
What is the function of the nucleus?
It contains the chromosomes, the hereditary units that direct all cellular activities.
What is cytoplasm (SI-to-plazm)?
It is the colloidal suspension that fills the cell from the nuclear membrane to the plasma membrane.
What is the function of cytoplasm?
It is the site of many cellular activities; consists of cytosol and organelles.
What is cytosol (SI-to-sol)
The fluid portion of the cytoplasm
What is the function of cytosol?
It surrounds the organelles.
What is endoplasmic reticulum (ER)?
en-do-PLAZ-mik re-TIK-u-lum
The network of membranes within the cytoplasm.
Rough ER has ribosomes attached to it; smooth ER does not.
What is the function of endoplasmic reticulum (ER)?
Rough ER modifies, folds, and sorts proteins.
Smooth ER participates in lipid synthesis.
What are ribosomes? (RI-bo-somz)
Small bodies free in the cytoplasm or attached to the ER, composed of RNA and protein.
What is the function of ribosomes?
They manufacture proteins.
What is the Golgi Apparatus? (GOL-je)
Layers of membranes
What is the function of the Golgi Apparatus?
It modifies proteins; sorts and prepares proteins for transport to other parts of the cell or out of the cell.
What are mitochondria? (mi-to-KON-dre-ah)
Large organelles with internal folded membranes.
What is the function of mitochondria?
They convert energy from nutrients into chemical adenosine triphosphate (ATP), commonly described as the energy compound of the cell.
What are lysosomes? (LI-so-somz)
Small sacs of digestive enzymes.
What is the function of lysosomes?
They digest substances within the cell.
What are peroxisomes? (per-OKS-ih-somz)
Membrane-enclosed organelles containing enzymes
What is the function of peroxisomes?
They break down harmful substances.
What are vesicles? (VES-ih-klz)
Small membrane-bound sacs in the cytoplasm.
What is the function of vesicles?
They store materials and move materials into or out of the cell in bulk.
What are centrioles? (SEN-tre-olz)
Rod-shaped bodies (usually two) near the nucleus
What is the function of centrioles?
They help separate the chromosomes during cell division.
What are surface projections?
Structures that extend from the cell.
What is the function of surface projections?
They move the cell or the fluids around the cell.
What are flagellum? (flah-JEL-um)
Long, whip-like extension from the cell.
What is the function of flagellum?
It moves the cell.
