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
