Ch 4 Vocab Flashcards
Electron microscope
A microscope that uses magnets to focus an electron beam through, or onto the surface of a specimen.
An electron microscope achieves a hundredfold greater resolution than a light microscope
Cell theory
The theory that all living things are composed of cells and that all cells come from other cells.
Scanning electron microscope (SEM)
A microscope that uses an electron beam to study the fine details of cell surfaces and other specimens
Transmission electron microscope (TEM)
A microscope that uses an electron beam to study the internal structure of thinly sectioned specimens
Prokaryotic cells
A type of cell lacking a membrane-enclosed nucleus and other membrane-enclosed organelles; found only in the domains bacteria and archaea
Eukaryotic cells
A type of cell that has a membrane-enclosed nucleus and other membrane-enclosed organelles.
All organisms except bacteria and archaea are composed of eukaryotic cells
Chromosomes
A threadlike gene carrying structure found in the nucleus of a eukaryotic cell and most visible during mitosis and meiosis; Also the main gene carrying structure of a prokaryotic cell.
Consists of one very long piece of chromatin, a combination of DNA and protein
Ribosomes
A cell structure consisting of RNA and protein organized into two subunits and functioning as the site of protein synthesis in the cytoplasm. In eukaryotic cells, the ribosomal subunits are constructed in the nucleolus.
Cytoplasm
The contents of a eukaryotic cell between the plasma membrane and the nucleus; consists of a semi fluid medium and organelles; can also refer the interior of a prokaryotic cell.
Nucleoid
A dense region of DNA in a prokaryotic cell
Flagella
A long cellular appendage specialized in locomotion.
Propel a prokaryotic cell through its liquid environment.
Organelles
A membrane-enclosed structure with a specialized function within a cell
Nucleus
Contains most of the cell’s DNA—its master plans— control’s the cell’s activities by directing protein synthesis
Cellular metabolism
All the chemical activities of a cell.
Flagella
Long cellular appendage specialized for locomotion
Organelles
Membrane-enclosed structure with a specialized function within a cell
Nucleus
An atoms central core, containing protons and neutrons.
Chromatin
Combination of DNA and proteins that constitutes eukaryotic chromosomes.
Nuclear envelope
Double membrane that encloses the nucleus, perforated with pores that regulate traffic with the cytoplasm.
Nucleolus
A structure within the nucleus where ribosomal RNA is made and assembled with proteins imported from the cytoplasm to make ribosomal subunits
Vesicles
A sac made of membrane in the cytoplasm of a eukaryotic cell
Endoplasmic reticulum
An extensive membranous network in a eukaryotic cell, continuous with the outer nuclear membrane and composed of ribosome studded (rough) and ribosome-free (smooth) regions
Rough ER
That portion of the endoplasmic reticulum with ribosomes attached that make membrane proteins and secretory proteins.
Smooth ER
Portion of the endoplasmic reticulum that lacks ribosomes
Golgi apparatus
A complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells
Lysosomes
A digestive organelle in eukaryotic cells; contains hydrolytic enzymes that digest engulfed food or damaged organelles
Vacuoles
Membrane-enclosed sac that is part of the endo membrane system of a eukaryotic cell and has diverse functions
Peroximones
An organelle containing enzymes that transfer hydrogen atoms from various substrates to oxygen producing and then degrading hydrogen peroxide.
Mitochondria
Organelle in eukaryotic cells where cellular respiration occurs
Chloroplasts
Organelle found in plants and photosynthesis protist that absorbs sunlight and uses it to drive the synthesis of organic molecules from carbon dioxide and water.
Cytoskeleton
A network of protein fibers in the cytoplasm of a eukaryotic cell.
Cilia
Short cellular appendage specialized for locomotion
Extra cellular matrix
Mesh work surrounding animal cells
Plasmodesmata
An open channel in a plant cell wall through which strands of cytoplasm connect from adjacent cells.
