A Tour of the Cell Flashcards
Basic Features of All Cells
plasma membrane, cytosol, chromosomes, ribosomes
Location of DNA in Eukaryotes
Nucleus
Location of DNA in Prokaryotes
Nucleoid (not membrane enclosed)
Cytoplasm
Region between the nucleus and the plasma membrane
Cytosol
semi-fluid substance in which organelles are suspended
Flagellum
present in some animal cells, composed of microtubules in an extension of the plasma membrane
Endoplasmic Reticulum
network of membranous sacs and tubes called cistern, membrane separates the internal cavity of ER called the ER lumen: active in membrane synthesis and other synthetic and metabolic processes; has rough and smooth regions
Nuclear envelope
double membrane enclosing the nucleus: selectively permeable; perforated by pores, lined by pore complex which regulates entry and exit of protein, RNA, and large macromolecules; continuous with ER
Nucleolus
structure inside nucleus involved in production of ribosomes; ribosomal RNA is synthesized and leaves nucleus through pore complex
Chromatin
material consisting of DNA and proteins; in between Nuclear Envelope and Nucleolus
Ribosomes
complexes that make proteins; either in cytosol (free ribosomes) or bound to rough ER or nuclear envelope (bound ribosomes)
Lysosome
digestive organelle where macromolecules are hydrolyzed
Mithocondrion
organelle where cellular respiration occurs and most ATP is generated, 2 layer membrane, inner layer (cristae), space between inner layer and outer layer (intermembraane space), second compartment (mitchondrial matrix)
Peroxisome
organelle with various specialized metabolic functions; produces hydrogen peroxide as a by-product and converts it to water
Microvilli
projections that increase surface area of cell
Cytoskeleton
reinforces cell’s shape; functions in cell movement, components are made of protein (microfilaments, intermediate filaments, microtubules)
Centrosome
region where the cell’s microtubules are initiated, include a pair of centrioles
Plant Organelles
Central Vacuole, Chloroplast, Plasmodesmata, Cell Wall
Cell Wall
Outer Layer that maintains cell shape: made of cellulose, protein, and polysaccharides
Plasmodesmata
channel through cell wall that connect cytoplasm of neighboring cells
Chloroplast
photosynthetic organelle; converts energy of sunlight to chemical energy
Central Vacuole
organelle in older plant cells; function include storage, breakdown of macromolecules and waste products
Nuclear Lamina
net of intermediate filaments that maintains shape of nucleus through nuclear envelope
Endomembrane system
nuclear envelope, ER, Golgi apparatus, lysosomes, vesicles, vacuoles, plasma membrane
Vesicles
sacs made of membrane used for transporting important biological molecules
Smooth ER
outer surface lacks ribosomes, enzymes in smooth ER help with synthesis of lipids, detoxify drugs and poisons (prevalent in liver cells), stores calcium ions in ER lumen (prevalent in muscle cells)
Rough ER
ribosomes on outer surface produce proteins such as insulin and secrete into the bloodstream, proteins secreted by Rough ER called glycoproteins (proteins with carbohydrates covalently bonded to them), glycoproteins transported by transport vesicles; also produces membranes by adding proteins and phospholipids to membrane
Golgi Apparatus
group of flatted membrane sacs (cisterns), has a cis face (located near the ER) for receiving and a trans face for shipping; products from the ER are modified and transported using vesicles, macromolecules are manufactured (ie;: pectin and other polysaccharides); molecular identification tags like phosphate group are added to Golgi products before shipping, vesicles carrying products may also have external molecules on their membranes as docking sites
Lysosome
membranous sac of hydrolytic enzymes (made in rough ER) that hydrolyze macromolecules in the acidic environment of lysosomes; carry out intercellular digestion in 2 ways: phagocytosis (engulf smaller organisms or food particles) and autophagy (lysosomes fuse with intercellular materials that are surrounded by a membrane and recycle their nutrients)
