Cell Characteristics Flashcards
all cells have
cell membrane, DNA, ribosomes, cytoplasm and cytoskeletal elements
what limits cell size
diffusion, DNA, ratio of surface area to volume
what organelles are specific to plant cells?
chloroplasts, plant cell walls, large central vacuole, plastid
what organelles are specific to animal cells?
centrosome, lysosomes
chromosome def
a DNA molecule - circular or linear, depending on the species - usually associated with specific proteins that bind to the DNA
ribosome def
a molecular machine consisting of RNA and proteins that is the site of protein synthesis
organelle def
any membrane-bound compartment inside a cell
cytoskeleton def
rod-like proteins inside cells that function in structural support, transport of materials, and movement in some species
cell wall def
a stiff structure outside the cell membrane composed of carbohydrates and other molecules
flagellum def
a long, flexible structure that extends from the cell and whips or rotates to propel the cell through water
nucleus def
an organelle unique to eukaryotes enclosed by a double membrane and containing the cell’s chromosomes
mitochondrion def
an organelle found in all eukaryotes that functions in “burning” sugars to provide energy for the cell
eukaryote def
a lineage of species with cells that contain a nucleus and mitochondria
prokaryote def
a species in the lineages archaea and bacteria, with cells that lack a nucleus
vacuole def
an organelle that stores key molecules, very prominent in most plant cells
chloroplast def
an organelle that contains the molecular machinery required for photosynthesis
cell wall def
a stiff structure outside of many types of cells, usually made primarily of carbohydrates
ER def
a eukaryotic organelle that forms a branching network of narrow tubes and flattened sacs. the place where proteins, membrane lipids, and other molecules are synthesized and/or processed. can have ribosomes associated with it or not
rough er
with ribosomes
smooth er
without ribosomes
golgi def
an organelle comprised of stacks, flattened sacs, where proteins and other molecules are processed and packaged for shipment to specific destinations.
actin filaments def
small-diameter cytoskeletal fibers made of subunits of the protein actin
intermediate filaments def
cytoskeletal fibers whose size is intermediate between those of actin filaments and microtubules and can be made from a variety of protein subunits
microtubules def
large-diameter, hollow cytoskeletal elements made of pairs of the proteins α-tubulin and β-tubulin.
