Unit 4 Flashcards
light microscope
visible light is passed through a specimen and then through a glass lenses
magnification
the ratio of an object’s image size to its real size
resolution
the measure of the clarity of the image, or the minimum
contrast
the difference in brightness between the light and dark areas of the image
scanning electron microscope (SEM)
focuses a beam of electrons onto the surface of a specimen, produces 3d images
transmission electron microscope (TEM)
focus a beam of electrons through a specimen
cell fractionation
breaks ups cells and separates the components using centrifugation
plasma membrane
a selective barrier that allows the passage of oxygen nutrients
nucleus
contains the cell’s genes
nuclear envelope
encloses the nucleus separating it from the cytoplasm
nuclear lamina
the shape of the nucleus, composed of protein filaments
chromosomes
DNA organized into units
chromatin
the DNA and protein of chromosomes together
nucleolus
located within the nucleus and is the site of ribosomal RNA synthesis
ribosomes
complexes of ribosomal RNA and protein
endomembrane system
nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vacuoles, plasma membrane
Endoplasmic reticulum
more than half of the total membrane in many eukaryotic cells
rough ER
has bound ribosomes that secrete glycoproteins, distribute transport vesicles, the membrane factory for the cell
smooth ER
synthesize lipids, metabolizes carbs, detoxifies drugs and poisons, stores calcium ions
golgi apparatus
flattened membranous sacs(cisternae), modified products of the ER, manufactures certain macromolecules, sorts and packages into transport vesicles
lysosomes
a membranous sac of hydrolytic enzymes that can digest macromolecules
phagocytosis
cells that can engulf another cell, which forms a food vacuole
autophagy
the process of reusing old and damaged cell parts
contractile vacuoles
found in many freshwater protists, pump excess water out of cells
central vacuoles
found in many mature plant cells, a repository for inorganic ions(K+ & Cl)
mitochondria
the site of cellular respiration, a metabolic process that uses oxygen to generate ATP
chloroplasts
found in plants and algae, the sites of photosynthesis
peroxisomes
a organelle that generates hydrogen peroxide, destroys the excess
endosymbiont theory
the theory that some organelles in eukaryotic cells and once were prokaryotic microbes
cytoskeleton
the network of fibers extended throughout the cytoplasm, helps support the cell and maintain the shape
microtubules
thickest component of the cytoskeleton, responsible in the movement of organelles and separate chromosomes during cell division
microfilaments
(actin filaments)
the thinnest components of cytoskeleton, responsible in changes of the cell shape, muscle contraction, cell division
intermediate filaments
middle range component of the cytoskeleton, and anchors of nucleus and certain organelles, forms the nuclear lamina
cell wall
extracellular structure that distinguishes plant cells from animal cells
extracellular matrix (ECM)
made up of glycoproeteins like collagen, proteoglycans, and fibronectin
integrin
ECM proteins that bind to
