Question | Answer |
light microscope | an optical instrument with lenses that bend visible light to magnify images of specimens. |
resolving power | a measure of the clarity of an image; the minimum distance that 2 points can be separated and still be distinguished as 2 separate points. |
transmission electron microscope (TEM)- | a microscope that passes an electron beam through very thin sections, primarily used to study the internal structure of cells. |
scanning electron microscope (SEM)- | A microscope that uses an electron beam to scan the surface of a sample to study details of its topography |
cell | The simplest collection of matter that can live. An organism’s basic units of structure and function. |
organelle | one of several formed bodies with specialized functions, suspended in the cytoplasm of eukaryotic cells. |
prokaryote | Type of cell without a membrane enclosed nucleus or membrane enclosed organelles, found in Bacteria and Archaea |
eukaryote | cell with membrane enclosed nucleus and organelles, in protists, plants, fungi, and animals. |
plasma membrane | Membrane at the boundary of every cell that acts as a selective barrier, therefore regulating the cell’s chemical composition. |
chromatin | Complex of DNA and proteins that make up a eukaryotic chromosome. When the cell is not dividing, chromatin exists as a mass of long thin fibers not visible with a light microscope |
chromosome | Thread like gene carrying structure found in the nucleus. Each chromosome consists of one very long DNA molecule and associated proteins. |
nucleus | chromosome containing organelle of a eukaryotic cell. |
nucleolus | a knot of chromatin that produces ribosomes |
ribosome | A cell organelle constructed in the nucleoluss and functioning as the site of protein synthesis in the cytoplasm; consists of rRNA and protein molecules which make up 2 subunits |
smooth endoplasmic reticulum | -The portion of the endoplasmic reticulum that is free of ribosomes. |
rough endoplasmic reticulum- | Portion of the endoplasmic reticulum studded with ribosomes. |
cytosol | Semi-fluid portion of the cytoplasm |
Golgi apparatus | an organelle in eukaryotic cells consisting of flat membranous sacs that modify, store, and route products of the endoplasmic reticulum. |
glycoprotein- | A protein covalently attached to a carbohydrate |
transport vesicle | A tiny membranous sac in a cell’s cytoplasm carrying molecules produced by the cell. |
lysosome | a membrane enclosed bag of hydrolytic enzymes found in the cytoplasm of eukaryotic cells. |
vacuole | A membrane enclosed sac taking up most of the interior of a mature plant cell and containing a variety of substances important in plant reproduction, growth and development |
mitochondrion | An organelle in eukaryotic cells that serves as the site of cellular respiration. |
matrix | The nonliving component of connective tissue, consisting of a web of fibers embedded in homogeneous ground substance that may be liquid, jelly-like or solid. |
cristae | The infoldings of the inner membrane of a mitochondrion that houses the electron transport chain and the enzyme catalyzing the synthesis of ATP. |
chloroplast | An organelle found only in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water. |
plastid | One of a family of closely related plant organelles, including chloroplasts, chromoplasts, and amyloplasts. |
thylakoid | A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy. |
grana | Stacked portions of the thylakoid membrane in the chloroplast. Grana function in the light reactions of photosynthesis. |
stroma | The fluid of the the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water. |
cytoskeleton | A network of tubules, microfilaments, and intermidiate filaments that branch throughout the cytoplasm and serve a variety of mechanical and transport functions |
microtubule | A hollow rod of tubulin protein in the cytoplasm of all eukaryotic cells and in cilia, flagella, and the cytoskeleton. |
microfilament | A solid rod of actin protein in the cytoplasm of almost all eukaryotic cells, making up part of the cytoskeleton and acting alone or with myosin to cause cell contraction. |
cilia | Short cellular appendages specialized for locomotion, formed from a core of nine outer doublet microtubules and two inner single microtubules ensheathed in an extension of plasma membrane. |
flagella | Long cellular appendages specialized for locomotion. The flagella of eukaryotes and prokaryotes differ in both structure and function. |
9+2 | 9 microtubules outside, 2 microtubules inside eukaryotic flagellum or cilium. |
pseudopod | A cellular extension of amoeboid cells used in moving and feeding |
cell wall | A protective layer external to the plasma membrane in plant cells, bacteria, fungi, and some protists. In plant cells, the wall is formed of cellulose fibers embedded in a polysaccharide-protein matrix. The primary cell wall is thin and flexible, whereas |
cell wall + | the secondary cell wall is stronger and more rigid and is the primary constituent of wood. |
fluid mosaic model | the currently accepted model of cell membrane structure, which envisions the mebrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids |
selective permeability | A property of biological membranes that allows some substances to cross more easily than others. |
passive transport | the diffusion of a substance across a biological membrane. |
active transport | The movement of a substance across a biological membrane against its concentration or electrochemical gradient with |
active transport + | the help of energy imput and specific transport proteins. |
diffusion | The spontaneous tendency of a substance to move down its concentration gradient from a more concentrated to a less concentrated area. |
hypertonic | In comparing two solutions, referring to the one with a greater solute concentration. |
hypotonic | In comparing two solutions, the one with a lower solute concentration. |
isotonic | Having the same solute concentration as another solution. |
osmosis | The diffusion of water across a selectively permeable membrane |
osmoregulation | the control of water balance in organisms living in hypertonic, hypotonic or terrestrial environments. |
endocytosis | the cellular uptake of micromolecules and particulate substances by localized regions of the plasma membrane that surround the substance and pinch off to form an intracellular vesicle. |
exocytosis | The cellular secretion of macromolecules by the fusion of vesicles with the plasma membrane. |
phagocytosis | A type of endosytosis involving large, particulate substances. |