2-1 Vocab Flashcards
Plasma Membrane
The membrane at the boundary of every cell that acts as a selective barrier, regulating the cell’s chemical composition
Nucleus
The organelle of a eukaryotic cell that contains the genetic material in the form of chromosomes, made up of chromatin
Actin
A globular protein that links into chains, two of which twist helically about each other, forming microfilaments (actin filaments) in muscle and other kinds of cells
Vacuoles
A membrane-bounded vesicle whose specialized function varies in different kinds of cells
Lysosome
A membrane-enclosed sac of hydrolytic enzymes found in the cytoplasm of animal cells and some protists
Stroma
The dense fluid within the chloroplast surrounding the thylakoid membrane and containing ribosomes and DNA; involved in the synthesis of organic molecules from carbon dioxide and water
Vesicles
A membranous sac in the cytoplasm of a eukaryotic cell
Tight Junctions
A type of intercellular junction between animal cells that prevents the leakage of material through the space between cells
Chromosomes
A cellular structure consisting of one DNA molecule and associated protein molecules. (In some contexts, such as genome sequencing, the term may refer to DNA alone.) A eukaryotic cell typically has multiple, linear chromosomes, which are located in the nucleus. A prokaryotic cell often has a single, circular chromosome, which is found in the nucleoid, a region that is not enclosed by a membrane
Cytosol
The semifluid portion of the cytoplasm
Peroxisome
An organelle containing enzymes that transfer hydrogen atoms from various substances to oxygen (O2), producing and then degrading hydrogen peroxide (H2O2)
Rough ER
That portion of the endoplasmic reticulum with ribosomes attached
Smooth ER
That portion of the endoplasmic reticulum that is free of ribosomes
Cristae
An infolding of the inner membrane of a mitochondrion. The inner membrane houses electron transport chains and molecules of the enzyme catalyzing the synthesis of ATP (ATP synthase)
Gap Junctions
A type of intercellular junction in animal cells, consisting of proteins surrounding a pore that allows the passage of materials between cells
Chloroplasts
An organelle found in plants and photosynthesis protists that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water
Organelles
Any of several kinds of membrane-enclosed structures with specialized functions, suspended in the cytosol of eukaryotic cells
Cell Wall
A protective layer external to the plasma membrane in the cells of plants, prokaryotes, fungi, and some protists. Polysaccharides such as cellulose (in plants and some protists), chitin (in fungi), and peptidoglycan (in bacteria) are important structural components of cell walls
Microtubules
A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella
Plasmodesmata
An open channel through the cell wall that connects the cytoplasm of adjacent plant cells, allowing water, small solutes, and some larger molecules to pass between the cells
