Cell organelles Flashcards
(12 cards)
Nucleus
-control center of the cell and contains the genetic materal
-surrounded by nuclear membrane (envelope) = double membrane that maintains a nuclear environment separate and distinct from the cytoplasm
-nuclear pore = located within the nuclear membrane and allows for selective two-way exchange of material between the cytoplasm and the nucleus
-nucleolus = located within the nucleus; rRNA is synthesized here; “darker spot” on the nucleus
Mitochondria
-power house of the cell
-different from other cell organelles because they are semi-autonomous = contain their own genes and replicate independently of the nucleus via binary fission
-they are examples of cytoplasmic or extra nuclear inheritance = transmission of genetic material without the need of the nucleus
-was created when an aerobic prokaryote was engulfed by an anaerobic prokaryotic to produce a symbiotic relationship
-outer membrane: barrier between the cytosol and the inner environment of the mitochondria
-inner membrane: arranged into numerous folds called Cristaes, which contains all the enzymes and molecules for the ETC.
-Cristae: great for increasing surface area for the ETC enzymes
-intermembrane space: space between the outer and inner membrane
-mitochondrial matrix: the space found within the inner membrane
-responsible for apoptosis
Lysosome
-membrane bound organelle that contains hydrolytic enzymes which help breakdown substrates
-work alongside endosome = endosomes transport, package, and sort cell material traveling to and from the membrane
-endosomes can take the material to the trans-golgi, cell membrane, or to the lysosomal path for degradation
-autolysis
Endoplasmic reticulum
-part of the nuclear envelope
-has double membrane
-has smooth and rough ER
-rough ER (rER): studded with ribosome. These ribosomes help with traveling of the protein directly into the lumen of the rER.
-smoother ER (sER): no ribosomes, synthesizes lipids and detoxifies certain drugs and poisons. Also transports proteins from the RER to the Golgi apparatus in vesicles
Golgi Apparatus
-stacked membrane-bound sacs
-materials come from the ER and once the material is inside the golgi, the cellular products may be modified by addition of groups such as carbs, phosphates, and sulfates.
-can also modify cellular products through signal sequencing which directs the delivery of the product to a specific cellular location
-after the Golgi, cellular products are repackaged into vesicles and directed to its correct cellular location
-if cellular products need to be secreted, exocytosis occurs
Peroxisomes
-contain hydrogen peroxide
-break down very long fatty acid chains via beta-oxidation
-synthesis of phospholipids and involved pentose phosphate pathway
Cytoskeleton
-provides structure to cell and helps to maintain its shape
-provides a pathway for material transport around cell
-microfilaments, microtubules, intermediate filaments
Microfilament
-made from rods of actin, resistance to both compression and fracture, providing protection for the cell
-actin can interact with myosin and ATP to produce muscle contraction
-play a role in cytokinesis (division of material between daughter cells): the cleavage furrow during mitosis is formed from microfilaments
Microtubules
-made from hollow polymers of tubulin proteins
-found throughout the cell and provide pathways along which motor proteins can carry vesicles, such as kinesin and dynein
-cilia and flagella are motile structures that are composed of microtubules
-cilia: cell projections involved in the movement of materials along the surface of the cell
-flagella: structures involved in the movement of the cell itself
-cilia and flagella share the same structure: 9+2 structure = 9 microtubules outside of the cell and 2 microtubules inside of the cell. This structure is unique ONLY to eukaryotes. Bacteria have a different structure
-centrioles found in the center of the centrosome
-kinetochores=microtubules
Intermediate filaments
-diverse group of filamentous proteins, which include keratin, desmin, vimentin, and lamins.
-involved in cell-to-cell adhesion or maintaining the overall integrity of the cytoskeleton
-able to withstand tremendous amount of tension, increasing cellular rigidity
-help anchor organelles, such as the nucleus
Epithelial tissue
-covers the body and lines its cavities to provide protection against pathogen and desiccation
-in certain organs, Epithelial tissue is involved in absorption, secretion, and sensation.
-bound tightly together to a layer of connective tissue known as basement membrane.
-epithelial cells found in the parenchyma=functional parts of the organ
-simple epithelial: one layer of cells
-stratified epithelial: multiple layer
-pseudostratified epithelial: appear to have multiple layers but in reality are one layer
-three different shapes of cells: cuboidal, columnar, and squamous
-cuboidal: cube-shaped cells
-columnar: long and thin
-squamous: flat and scale-like
Connective tissue
-supports the body and provides a framework for the epithelial cells
-main contributors to the stroma aka support structures
-ex: bone cartilage, tendons, ligaments, adipose tissue, and blood
-most cells in connective tissue produce and secrete material such as collagen and elastin to form the ECM
