Chapter 4 Flashcards
Cell Structure
What is cell theory?
A biological concept that states that one or more cells comprise all organisms; the cell is the basic unit of life; and new cells arise from existing cells.
What is a cell wall?
A rigid cell covering comprised of various molecules that protects the cell, provides structural support, and gives shape to the cell.
What is a central vacuole?
A large plant cell organelle that regulates the cell’s storage compartment, holds water, and plays a significant role in cell growth as the site of macromolecule degradation.
What is a centrosome?
A region in animal cells made of two centrioles that serves as an organizing center for microtubules.
What is chlorophyll?
A green pigment that captures the light energy that drives the light reactions of photosynthesis.
What is a chloroplast?
A plant cell organelle that carries out photosynthesis.
What is chromatin?
A protein-DNA complex that serves as the chromosomes’ building material.
What is a chromosome?
A structure within the nucleus that comprises chromatin and contains DNA, the hereditary material.
What is a cilium?
A short, hair-like structure that extends from the plasma membrane in large numbers and functions to move an entire cell or move substances along the cell’s outer surface.
Plural = cilia
What is cytoplasm?
The entire region between the plasma membrane and the nuclear envelope, consisting of organelles suspended in the gel-like cytosol, the cytoskeleton, and various chemicals.
What is a cytoskeleton?
A protein fiber network that collectively maintains the cell’s shape, secures some organelles in specific positions, allows cytoplasm and vesicles to move within the cell, and enables unicellular organisms to move independently.
What is cytosol?
The cytoplasm’s gel-like material in which cell structures are suspended.
What is a desmosome?
Linkages between adjacent epithelial cells that form when cadherins in the plasma membrane attach to intermediate filaments.
What is an electron microscope?
An instrument that magnifies an object using an electron beam that passes and bends through a lens system to visualize a specimen.
What is the endomembrane system?
A group of organelles and membranes in eukaryotic cells that work together modifying, packaging, and transporting lipids and proteins.
What is the endoplasmic reticulum (ER)?
A series of interconnected membranous structures within eukaryotic cells that collectively modify proteins and synthesize lipids.
What is a eukaryotic cell?
A cell that has a membrane-bound nucleus and several other membrane-bound compartments or sacs.
What is the extracellular matrix?
Material secreted from animal or fungal cells that provides mechanical protection and anchoring for the cells in the tissue.
What is a flagellum?
A long, hair-like structure that extends from the plasma membrane and moves the cell.
Plural = flagella
What is a gap junction?
A channel between two adjacent animal cells that allows ions, nutrients, and low molecular weight substances to pass between cells, enabling the cells to communicate.
What is the Golgi apparatus?
A eukaryotic organelle comprised of a series of stacked membranes that sorts, tags, and packages lipids and proteins for distribution.
What is an intermediate filament?
A cytoskeletal component, comprised of several fibrous protein intertwined strands, that bears tension, supports cell-cell junctions, and anchors cells to extracellular structures.
What is a light microscope?
An instrument that magnifies an object using a beam of visible light that passes and bends through a lens system to visualize a specimen.
What is a lysosome?
An organelle in an animal cell that functions as the cell’s digestive component; it breaks down proteins, polysaccharides, lipids, nucleic acids, and even worn-out organelles.
