To protect the cell and regulate what enters and exits.
Ribosomes.
To maintain the shape of the organism and protect it from mechanical injury.
Mitochondria.
Fibroblasts.
It provides shape, structural support, and directed movement of molecules and organelles.
Chloroplasts.
To provide structure and support.
By noncovalent bonds to the cytoplasmic surface.
Ribosomes and the cytoskeleton.
To sort processed molecules and package them into vesicles coated with clathrin.
They link clathrin to membrane-bound receptors and target clathrin-coated vesicles.
The Golgi apparatus.
To store nutrients and waste products, and to maintain turgor pressure.
A complex mixture of proteins, nucleic acids, ions, and small molecules.
Substances such as polysaccharides and proteins secreted by some bacteria.
Capsule and slime layer.
They do not retain the dye crystal violet.
A thin peptidoglycan layer.
Inclusions of the iron mineral magnetite that help some prokaryotes orient with the Earth's magnetic field.
Ribosomes and a diverse number of macromolecules and smaller metabolites.
RNA and proteins.
It increases hydrogen ion concentration, reducing internal pH.
Less than 5.
The binding of a specific ligand to its cognate receptor on the plasma membrane.
Membranous sacs that bud off from a donor membrane and fuse with the membrane of a different compartment.
They deliver molecular cargo to the Golgi complex for further processing.
Membrane proteins and water-soluble proteins.
A lipid bilayer with a variety of integral proteins embedded.
Ribosomes.
To transfer molecules from older to younger cisternae.
They contain carbohydrate groups and are covalently bound to proteins and certain lipids.
Complex lipid molecules that stabilize bacterial membranes.
A spacious, irregularly shaped region that contains a long, circular DNA molecule called a chromosome.
Sulfur granules.
They determine the fate of internalized molecules.
A cellular process where plasma membrane protein receptors take in specific substances.
Actin, actin-binding proteins, and spectrin.
It provides mechanical strength and determines cell shape.
Counterclockwise rotation pushes the cell forward, while clockwise rotation causes a stop-and-tumble motion for reorientation.
The process where COPI-coated vesicles return resident ER proteins to the ER.
Dynamin.
It serves as a reservoir for calcium, which triggers muscle contraction.
Rough ER (RER) and Smooth ER (SER).
Covalently attached.
Vast numbers of densely packed and interacting molecules that perform specific tasks required for life.
Actin microfilaments and other proteins linked to the cytoskeleton.
Protein synthesis.
The SER lacks attached ribosomes.
Protein complexes involved in DNA synthesis and gene expression regulation.
Tubular-vesicular networks that mature to form late endosomes.
Multivesicular bodies.
Rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER).
They can be recycled, delivered to the TGN, or degraded in lysosomes.
They facilitate efficient folding and prevent aggregation of partially folded polypeptides.
Involved in the synthesis of lipid molecules.
To provide mechanical strength and shape to the cell, and to select molecules that can enter or exit the cell.
Approximately 35% in hepatocytes and 60% in pancreatic acinar cells.
Cis-Golgi network (CGN).
To store genetic material and control cell activities.
Large granules that contain organic or inorganic substances.
Glycogen or poly-β-hydroxybutyric acid.
The process where secretory vesicles fuse with the plasma membrane to release their contents.
Calcium ions (Ca2+) in response to an external signal.
Lipid synthesis, biotransformation, and Ca2+ storage.
It consists of flattened, saclike membranous vesicles resembling a stack of plates.
Fine, hair-like structures that allow cells to attach to food sources and host tissues.
To transfer genetic information from donor cells to recipients through a process called conjugation.
Nutrient digestion, transport, or chemotaxis.
Receptor-mediated endocytosis.
A soluble protein complex called a triskelion, consisting of three heavy chains and three light chains.
It regulates the number of receptors in the plasma membrane and can continue signaling after receptors enter endosomes.
A system of interconnected membranous tubules, vesicles, and large flattened sacs that constitutes more than half of a cell’s total membrane.
To regulate the movement of substances in and out of the cell.
Uniform and grainy, except for inclusion bodies.
In the endoplasmic reticulum (ER).
A source of phosphate for nucleic acid and phospholipid synthesis.
Secretion of collagen by fibroblasts.
It results in muscle contraction.
Digestive enzymes called acid hydrolases.
They catalyze the attack of a water molecule on ester and amide linkages under acidic conditions.
They contribute to the autophagic degradation of debris within cells.
An irregularly shaped region where circular DNA molecules are located.
A response initiated by the RER to restore proteostasis when stress is severe.
An ER subdomain where newly synthesized proteins and lipids exit in coated vesicles.
Because of the numerous ribosomes that stud its cytoplasmic surface.
Covalent modifications, including the addition of sugar molecules and sulfate or phosphate groups.
Peptidoglycan.
The thickness and chemical composition of the cell wall and its adjacent structures.
They allow them to avoid detection by host immune systems and facilitate colonization.
Disorganized accumulations of polysaccharides formed when microorganisms adhere to surfaces.
Small circular DNA molecules that can replicate independently of the chromosome.
They often carry DNA sequences that code for antibiotic resistance.
They synthesize a protein that inactivates the antibiotic before it can damage the cell.
Energy transduction processes such as photosynthesis and respiration.
The cisternal maturation model.
They are recycled back to the plasma membrane.
They return to the ER via vesicles that have COPI coats.
Cytoskeleton.
To synthesize proteins and lipids.
To modify, sort, and package proteins for secretion.
Peroxisomes.
Lipopolysaccharide.
Cytoplasmic membrane.
A phospholipid bilayer reinforced with hopanoids.
They act as selective permeability barriers, receptors for nutrients and toxins, and transport proteins for nutrient uptake and waste disposal.
The forming (cis) face and the maturing (trans) face.
A condition caused by the accumulation of misfolded polypeptides that threatens overall cell function.
Sarcoplasmic reticulum (SR).
A lipid bilayer and various integral and peripheral proteins.
They regulate the passage of ions and molecules in and out of the cell.
A carbohydrate coat on the extracellular face of a eukaryotic cell that plays roles in cell recognition and adhesion.
Tooth decay, cystic fibrosis, and tuberculosis.
They are responsible for symptoms such as fever and shock.
Through porins, which are transmembrane protein complexes.
A gelatinous fluid that includes peptidoglycan and various proteins.
A flexible corkscrew-shaped protein filament used for locomotion, pushing cells forward when rotating counterclockwise.
They are interconnected.
Eukaryotic cells are larger, more structurally complex, and contain membrane-bound organelles.
They contain specific biomolecules and are specialized to perform distinct functions efficiently.
They allow the cell to respond to external stimuli.
The ER lumen or cisternal space.
They are threaded or translocated through the membrane during ongoing protein synthesis.
They are packaged into vesicles.
A gelatinous material synthesized by fibroblasts that binds cells together and regulates cell behavior.
A three-dimensional meshwork of proteins that reinforces the inner surface of the plasma membrane.
Processing, packaging, and distribution of cell products.
Glycosylation (covalent attachment of sugar molecules) to proteins and lipids.
It facilitates signal transduction processes.
The process where vesicles move from the ER to the Golgi apparatus.
They remain embedded in the membrane when hydrophobic segments enter it.
An extensive set of interconnecting internal membranes that divide the cell into functional compartments.
Mitochondria, peroxisomes, and chloroplasts in plant cells.
Synthesis of proteins, membrane lipids, steroid molecules, and storage of calcium ions.
16% in hepatocytes and 1% in pancreatic acinar cells.
