Chapter 5-Eukaryotic Microbial Structure Flashcards
What are the two groups of eukaryotic microorganism?
protists and fungi
What are some unique and common features of the eukaryotic cells?
membrane limited nuclei, unit membrane bound organelles with specific functions, intracytoplasmic unit membrane complex (transport system), more structurally complex and larger than bacterial and archaeal cells
structure with 1 or 2 membranes, at least one function
organelle
consists of cell membrane and all coverings external to it, algae and fungi have cell walls, protozoa don’t
cell envelopes
85% lipid bilayer, 14% protein, 1% carbohydrates, hydrophobic interior of bilayer, phosphoglycerides and sterols added for extra strength
eukaryotic cell membrane
True or False: Eukaryotic cell membrane proteins play no role in energy metabolism?
True, they play no role
consists of 90 to 92% water with dissolved solutes, includes cytoskeleton
cytoplasm of eukaryotes
protein fibers that form the cytoplasmic matrix, composed of microfilaments and microtubules, give cell shape and assist movement, provide attachment site for organelles
cytoskeleton
small, protein filaments, 4 to 7 nm in size, made of actin protien, scattered throughout cytoskeleton
microfilaments
heterogeneous elements of cytoskeleton, about 10nm in diameter, vimentin and keratin classes, play a structural role, link cells for tissues
intermediate filaments
small cylinder shape, provide cell with distinct shape, assist in mitotic tracking, intracellular tracking, and mitosis/meiosis
microtubules
have ribosomes attached, synthesis of secreted proteins, transport of protiens
rough endoplasmic reticulum
devoid of ribosomes, synthesis of secreted proteins and cell membrane proteins, lipid biosynthesis
smooth endoplasmic reticulum
unit membranous organelle made of cisternae on each, cis and trans faces, stacks of cisternae, assist in packing and secretion of materials and intracellular modifications
golgi apparatus
unit membrane bound vesicles, eukaryotic only, assist in intracellular digestion, maintain an acidic environment by pumping protons interiorly
lysosome
enzyme that hydrolyze molecule, best under acid conditions
hydrolase
used to move materials to various sites within the cell, proteins made by RER, enter RER lumen released into small budding vesicles, intracellular movement guided by cytoskeleton, modified at golgi, moves from cis face to trans face where transport vesicles released
secretory pathway
What is the quality assurance mechanism of the secretory pathway?
assures that nonfunctional proteins are destroyed ubiquitin polypeptides
done by all eukaryotic cells, performed on materials into cell too big for transport proteins, solutes or particles are taken up by and enclosed in vesicles, materials to lysosome and destroyed
endocytosis
What are the 3 kinds of endocytosis?
(1) phagocytosis
(2) clathrin
(3) caveolae
type of endocytosis done where there are no cell walls, cell surface protrudes and engulfs particles, fuse with lysosome and resulting vesicles called phagosomes
phagocytosis
initiated by the protein clathrin, coated pits that bind to macromolecule, kind of receptor mediated endocytosis
clathrin endocytosis
kind of endocytosis where caveolin is present, pinch off at membrane, appear like small caves
ceveolae endocytosis
delivery of materials to be digested by route not involving endocytosis, macroautophagy includes digestion and recycling of cytoplasmic contents, a double membrane surrounds the cell component, forms an authophagosome
autophagy
What happens once a lysosome is formed?
digestion occurs w/o release of lysosome enzymes into matrix, as digestion occurs products leave and are used as nutrients, residual body forms and is released in to the outside
double membrane organelle, house genetic material, chromatin complex is visible, 5 histones (H1, H2A, H2B, H3, H4), chromatin condenses into chromosomes during division
nucleus
important in ribosome synthesis, direct synthesis and processing of rRNA, ribosomes mature in cytoplasm
nucleolus
larger that 70s, attached to ER or cytoskeleton, proteins made are secreted out, inserted into cell membrane or transported into organelles, those attached to cytoskeleton synthesize nonsecretory and nonomembrane proteins
ribosomes
powerhouse of cell, found in most eukaryotic cell, carries out aerobic respiration, site of tricarboxlyic acid cycle, ATP generated by ETC, same size as bacterial cells, reproduce by binary fission
mitochondria
contains transport porins similar to gram negative bacteria
outer membrane of mitochondria
highly folded to form cristae
inner membrane of mitochondria
contain ribosomes, DNA, CaPO4 granules, and enzymes
matrix of mitochondria
a small energy conservation organelle in some anaerobic protists, descended from common mitochondrial ancestor
hydrogenosomes
type of plastid, pigment organelle of plants and algae, photosynthetic reaction, 2X unit membrane, stroma within inner membrane (site of dark rxn photosynthesis)
chloroplast
flattened sacs within chloroplast
thylakoid (site of light dependent photosynthesis)
stacks of thylakoid
grana
5 to 20 um in length, beat with two phases, work like oars
cilia
100 to 200 um long, move in undulating fushion, tinsel (tip pulls cell along) or wiplash (naked flagellum)
flagella
unit membrane bound cylinders, axoneme (set of microtubules in a 9+2 arrangement), basal body at base to direct
ultrastructure of cilia and flagella
cytoplasmic extensions surrounded by cell membrane with structure maintained by cytoskeleton and microfilaments, found in some protozoans
pseudopods
