Chapter 3 - Cells Flashcards
cytoplasm
a thick solution that fills each cell and is enclosed by the cell membrane
organelle
specialized structures within a cell
nucleus (biology)
a large, membrane-bound structure in most cells that contains the genetic code
three main parts of a cell
plasma membrane, cytoplasm, nucleus
plasma membrane
a membrane that surrounds the entire cell, forming its outer boundary; it is made up of phospholipids and cholesterol
hormone
a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action
cytoskeleton
a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence
ribosome
a minute particle consisting of RNA and associated proteins found in large numbers in the cytoplasm of living cells; it helps with protein synthesis
endoplasmic reticulum (ER)
a network of membranes inside a cell through which proteins and other molecules move, made of two types: rough ER and smooth ER
rough ER
part of endoplasmic reticulum that receives, folds, and transports newly made proteins
smooth ER
part of endoplasmic reticulum that creates the membrane for the cell
Golgi apparatus
a complex of vesicles (pouches) and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion (e.g. mucus) and intracellular transport
mitochondrion
an organelle in the cell that produces energy for the cell (e.g. ATP)
lysosome
the part of the cell that digests nutrients and helps to destroy harmful microbes
centrosome
an organelle in the cell that organizes microtubules; involved in the process of cell division
microtubule
a microscopic tubular structure present in numbers in the cytoplasm of cells, sometimes aggregating to form more complex structures
centriole
a minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division
microvilli
small, fingerlike projections of the plasma membrane of some cells; these projections increase the surface area of the cell and thus increase its ability to absorb substances.