cell 1: cytoplasm Flashcards
all cells originate from a
zygote, which undergoes repeated cell divisions
cells that have not differentiated and havent reached their mature form
stem cells
what does the cytoplasm consist of
cytosol
organelles
cytoskeleton
inclusions
everything except the nucleus
cell is separated from the external environment by what
the plasma membrane (plasmalemma)
what does the plasma membrane consist of
2 layers of phospholipid molecules
cholesterol
integral vs peripheral protein on the plasma membrane
integral - embedded in the phospholipid bilayer
peripheral - attached to the inner or outer surface
glycocalyx function and location and composition
-involved in cell recognition and attachment to other cells or extracellular matrix
-covers outer surface of the membrane
-made of glycolipids, glycoporteins - have carbohydrate molecules attached
water passes through what
aquaporins
endocytosis
the process of bringing materials into the cell
phagocytosis
-engulfing of bacterial, protozoa, dead cells or extracellular debris
-these materials become surrounded by membrane and form a phagosome (phagocytic vesicle)
what are 2 phagocytic cells
macrophages
neutrophils
pinocytosis
engulfing of extracellular fluid and dissolved materials
transcytosis
movement of pinocytic vesicles across a cell
clathrin
one of the main coating proteins
receptor-mediated endocytosis
after ligand binding to surface receptors, the receptor-ligand complex is engulfed in coated pits, eventually forming coated vesicles
a transient increase in what allows exocytosis to occur
increase in cytosolic Ca2+
cells receive signals called
target cells
endocrine signaling includes what
hormones
how are hormones carried out
in the blood
how does paracrine signaling work
chemical signals act on local cells
how does autocrine signaling work
signals bind to receptors on the same
how does synaptic signaling work
neurotransmitter molecules are released at special cell junctions, called synapses
chemical signals are converted to electrical signals
how does hydrophilic signaling work
-typically polypeptide hormones or neurotransmitters
-activate receptors on cell surfaces
-channel-linked, enzymatic, G-protein-coupled
-signal transduced by second messenger, starting a cascade of biochemical events
how does hydrophobic signaling work
-bind to carrier proteins, which transport signaling molecules in the bloodstream
-signaling molecules are released, penetrate the plasma membrane, and bind to intracellular receptors
-receptor-hormone complex moves into the nucleus, binds to DNA, prompting gene transcription
what is synthesized in ribosome nucleolus and why does it stain intensely basophilic
rTNA syntehsized
bc of phosphates
what does rough ER do and stains basophilic bc of what
segregation of proteins not destined for cytosol, assembly of multichain proteins, posttranslational changes of newly formed peptides
bc of ribosomes
does smooth ER have ribosomes and what is its function
-synthesis of membrane phospholipids
-steroid synthesis
-degradation of toxins and drugs
-sequestering Ca2+ ions (in SARCOPLASMIC RETICULUM of muscle)
golgi apparatus roles
-modifies proteins (glycosylation, sulfation, phosphorylation, proteolysis)
-packages, concentrates and stores secretory products in VESICLES
ZYGOGEN GRANULES contain what
digestive enzymes
secretory vesicles/granulues originate from where and function
originate from golgi apparatus
store secretion products until release is stimulated by metabolic, hormonal, or neural message
lysosome contains what enzymes
hydrolytic enzymes in acid pH
“-eases”
lysosomes are abundant in what cells
phagocytic cells
lysosomes formed where and proteins labeled w what
formed by golgi apparatus
proteins labled with MANNOSE-6-PHOSPHATE (M6P)
w lysosomes, what remains after digestion and contains undigested materials
RESIDUAL BODY
ETC enzymes embedded where and matrix enzymes involved w what
ETC enzymes embedded in inner membrane
matrix enzymes involved w citric acid cycle
proteasome roles
(cylindrically shaped cytoplasmic protein complexes)
-recognize ubiquitin-labled proteins
-degrade denatured or nonfunctional proteins
-remove proteins not needed by the cell (thus, limit time of protein activity)
peroxisome function and how
-utilize oxygen to make hydrogen peroxide
-catalase in peroxisome breaks down H2O2
what are inclusions
nonmotile, non-metabolic
-are not organelles
-ex: fat droplets, glycogen granules, lipofuscin granules
