Chapter 4: Key Terms Part 2 Flashcards
The thinnest of the three main kinds of protein fibers making up the cytoskeleton of a eukaryotic cell; a solid, helical rod composed of the globular protein actin
Microfilament
A digestive organelle in eukaryotic cells; contains hydrolytic enzymes that digest the cell’s food and wastes
Lysosome
A photograph taken through a microscope
Micrograph
The thickest of the three main kinds of fibers making up the cytoskeleton of a eukaryotic cell; a straight, hollow tube made of globular proteins called tubulins. Microtubules form the basis of the structure and movement of cilia and flagella
Microtubule
The fluid contained within the inner membrane of a mitochondrion
Mitochondrial Matrix
An organelle in eukaryotic cells where cellular respiration occurs. Enclosed by two concentric membranes, it is where most of the cell’s ATP is made
Mitochondrion
A double membrane, perforated with pores, which encloses the nucleus and separates it from the rest of the eukaryotic cell
Nuclear Envelope
A dense region of DNA in a prokaryotic cell
Nucleoid
A structure within the nucleus of a eukaryotic cell where ribosomal RNA is made and assembled with proteins imported from the cytoplasm to make ribosomal subunits
Nucleolus
The genetic control center of a eukaryotic cell
Nucleus
A membrane-enclosed structure with a specialized function within a cell
Organelle
An organelle containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide
Peroxisome
The membrane that sets a cell off from its surroundings and acts as a selective barrier to the passage of ions and molecules into and out of the cell; consists of a phospholipid bilayer in which are embedded molecules of protein and cholesterol
Plasma Membrane
An open channel in a plant cell wall through which strands of cytoplasm connect from adjacent cells
Plasmodesma
A type of cell lacking a membrane-enclosed nucleus and other membrane-enclosed organelles; found only in the domains Bacteria and Archae
Prokaryotic Cell
A cell structure consisting of RNA and protein organized into two subunits and functioning as the site of protein synthesis in the cytoplasm. The ribosomal subunits are constructed in the nucleolus
Ribosome
A network of interconnected membranous sacs in a eukaryotic cell’s cytoplasm. Rough ER membranes are studded with ribosomes that make membrane proteins and secretory proteins
Rough ER
A microscope that uses an electron beam to study the surface architecture of a cell or other specimen
Scanning Electron Microscope (SEM)
The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water; Sugars are made in the stroma by the enzymes of the Calvin cycle
Stroma
One of a number of disk-shaped membranous sacs inside a chloroplast. Thylakoid membranes contain chlorophyll and the enzymes of the light reactions of photosynthesis. A stack of thylakoids is called a granum
Thylakoid
A microscope that uses an electron beam to study the internal structure of thinly sectioned specimens
Transmission Electron Microscope (TEM)
A tiny membranous sac in a cell’s cytoplasm carrying molecules produced by the cell. The vesicle buds from the endoplasmic reticulum or Golgi and eventually fuses with another membranous organelle or the plasma membrane, releasing its contents
Transport Vesicle
A membrane-enclosed sac that is part of the endomembrane system of a eukaryotic cell, having diverse functions
Vacuole
A sac made of membrane in the cytoplasm of a eukaryotic cell
Vesicle
