Chapter 6 Flashcards
light microscope
visible light is passed through the specimen and then through the glass lenses. the lenses refract (bend) the light in such a way that the image of the specimen is magnified as it is projected into the eye or into a camera.
organelles
membrane enclosed structures within eukaryotic cells
electron microscope
focuses a beam of electrons through the specimen or onto its surface
scanning electron microscope (SEM)
used to study the surface of the speciment
transmission electrons microscope
used to study internal structure of cells
cell fractionation
technique to study cell structure and function; takes cells apart and separates major organelles and other subcellular structures from one another
cytosol
semifluid, jellylike substance called
nucleoid
DNA is concentrated here; not membrane enclosed
chromosomes
discrete units DNA is organized into
chromatin
complex of dna and proteins making up chromosomes
nuclear envelope
encloses the nucleus, separating its contents from the cytoplasm
nuclear lamina
netlike array of protein filaments that maintains the shape of the nucleus by mechanically supporting the nuclear envelope
ribosomes
complexes made of ribosomal RNAs and proteins
endoplasmic reticulum
extensive network of membranes that it accounts for more than half the total membrane in many eukaryotic cells
smooth er
surface lacks ribosomes
rough er
studded with ribosomes
glycoproteins
proteins with carbohydrates covalently bonded to them
transport vesicles
vesicles in transit from one part of the cell to another
golgi apparatus
packaging center
lysosome
digestive enzyme
phagocytosis
cell engulfing/eating the other
vacuole
large vesicles derived from the ER and golgi apparatus
endosymbiont theory
early ancestor of eukaryotic cells engulfed an oxygen-using nonphotosynthetic prokaryotic cell, and the engulfed cell formed a relationship with the host cell in which it was enclosed, becoming an endosymbiont
thylakoids
interconnected sacs inside the chloroplast
grannum
stacks in the thylakoid
stroma
fluid outside the thylakoid
peroxisome
specialized metabolic compartment bounded by a single membrane
cytoskeleton
a network of fibers extending throughout the cytoplasm
microtubules
hollow rods constructued from globular proteins called tubulins
centrosome
a region that is often located near the nucleus
cilia
cellular extensions that contain microtubules
flagella
cellular extensions that contain microtubules
microfilaments
thin solid rods built of actin
actin
a globular protein
dyneins
large motor proteins that are attached along each outer microtubule
cell wall
extracellular structure of plant cells
