Eukaryotic cells Flashcards
plasma membrane
a selectively permeable, lipid bilayer surrounding each cell
cytoplasm
the interior of a cell (minus the nucleus) containing organelles suspended in a jelly-like substance called the cytosol
nucleus
contains cells genetic material as it consists of chromosomes made up of chromatin which contain DNA
nuclear envelope
a double membrane each being a lipid bilayer. contains pores for the transfer of molecules, lined by a pore complex
nucleolus
location of ribosomal RNA (rRNA), responsible for transcription and ribosome assembly.
ribosomes
complexes of protein and rRNA responsible for protein synthesis. (can be freely suspended in the cytosol, or bound to the endoplasmic reticulum or nuclear envelope.)
Endoplasmic reticulum
membraneous system of interconnected tubules and flattened sacs
smooth ER
involved in numerous metabolic processes including lipid synthesis, drug detoxification, and calcium storage
Rough ER
covered in ribosomes synthesizing proteins to be exported. involved in protein glycosylation and membrane synthesis.
Transitional ER
region of rough ER from which transport vesicles bud off and move to other regions of the cell
Golgi apparatus
4-8 membranous sacs called cisternae. The cis face is orientated towards the ER and receives vesicles and the trans face sorts molecules and releases vesicles for transport elsewhere in the cell.
lysosomes
a membranous sac with an acidic interior containing hydrolytic enzymes for the hydrolysis of macromolecules
phagocytosis
the endocytosis (internalization) of large particles coupled to digestion
autophagy
recycling of a cells organic material
Vacuoles
large vesicles with an internal solution differing in composition from the cytoplasm
food vacuoles
formed by phagocytosis
contractile vacoules
pump excess water out of the cell. found in aquatic, unicellular eukaryotes.
hydrolytic vacuoles
similar to lysosomes. found in plants and fungi
central vacuole
found in plant cells. stores inorganic ions and contributes to cell growth and structure.
mitochondria
a powerhouse of the cell. sites of cellular respiration produce ATP
chloroplasts
specialized plastids that are the sites of photosynthesis and produce sugars.
thylakoids
membranous system of flattened interconnected sacs, a stack of thylakoids is a granum
stroma
the fluid outside of the thylakoids
peroxisome
bound by a single lipid bilayer membrane. involved in the breakdown of fatty acids and detoxification of harmful compounds
cytoskeleton
a dynamic network of fibres extending through the cytoplasm. provides mechanical support and anchorage for organelles. consists of microtubules, microfilaments and intermediate filaments.
microtubule
hollow rods that contribute to cell shape and support and serve as tracks for motor proteins
centrosome
a region near the nucleus, from which microtubules grow.
centrioles
a pair of nine sets of triplet microtubules in a centrosome.
flagella and cilia
microtubule containing extensions of a cell involved in cell motility movement of fluid and signaling
microfilaments (actin filaments)
a twisted double chain of actin subunits involved in tension bearing. contribute to cell shape
intermediate filaments
intermediate in size and more permanent than microtubules and microfilaments.
cell wall
an extracellular layer of cellulose microfibrils embedded in a matrix of polysaccharides and proteins. includes the primary cell wall and the secondary cell wall.
extracellular matrix
an extracellular layer around animal cells that includes glycoproteins, polysaccharides and proteoglycans
plasmodesmata
channels connecting plant cells allowing transfer of compounds between cells
gap junctions
animal cell equivilants of plasmodesmatata
tight junctions
tight seals between cells preventing the passage of extracellular fluid.
