Intracellular compartments and sorting
This short stretch of amino acids that directs a newly made protein to the correct organelle inside the cell.
Signal Sequence
This mitochondrial protein complex is responsible for recognizing cytosolic precursor proteins and transporting them across the outer mitochondrial membrane.
TOM complex
This coat protein packages newly synthesized proteins into transport vesicles that bud from ER exit sites and travel to the Golgi apparatus.
COPII
This overall set of chemical reactions includes both energy‑releasing pathways and energy‑requiring pathways within the cell.
metabolism
This two‑stage process uses energy from electron transfer to generate a proton gradient and then converts that gradient into ATP.
oxidative phosphorylation
Proteins that lack any sorting signal remain in this cellular location after they are synthesized.
cytosol
This mitochondrial inner membrane translocator inserts proteins that are synthesized in the matrix as well as some proteins that first enter the matrix via TIM23 but cannot be properly inserted due to their topology.
OXA complex
These proteins form a discrete inner layer of clathrin‑coated vesicles and link specific cargo molecules to the clathrin coat.
adaptor proteins (adaptins)
This activated electron carrier transports high‑energy electrons produced during glycolysis and the citric acid cycle to the electron transport chain.
NADH
This coupling mechanism links electron transport and proton pumping to ATP synthesis across the inner mitochondrial membrane.
chemiosmotic coupling
This mechanism of protein transport allows proteins and RNA to move directly between two topologically equivalent compartments without crossing a membrane
gated transport through nuclear pore complexes
Unlike most organelles, proteins can enter this organelle in a fully folded state, using ATP and peroxin proteins.
peroxisome
This GTP‑binding protein wraps around the neck of a budding clathrin‑coated vesicle and uses GTP hydrolysis to pinch it off from the membrane.
Dynamin
This process produces ATP directly from high‑energy phosphate intermediates without the involvement of a proton gradient.
substrate‑level phosphorylation
This electrochemical gradient across the inner mitochondrial membrane consists of both a pH difference and a voltage difference.
proton‑motive force (electrochemical proton gradient)
This small GTP-binding protein establishes directionality for nuclear import and export
Ran-GTPase
This process adds a preformed oligosaccharide to an amino acid residue of a protein as it enters the ER lumen.
N‑linked glycosylation
Specificity in vesicle targeting is achieved first by this class of small GTP‑binding proteins and then stabilized by complementary transmembrane protein pairing.
This metabolic pathway converts pyruvate into acetyl‑CoA, releases carbon dioxide, produces NADH, and occurs in the mitochondrial matrix.
pyruvate oxidation
This large multiprotein complex uses the flow of protons to mechanically rotate a central stalk, directly converting mechanical energy into chemical energy
ATP synthase
The ER lumen, Golgi lumen, and extracellular space are considered this because proteins can move between them without crossing a membrane.
topologically equivalent compartments
This ER stress response restores homeostasis by simultaneously increasing chaperone gene expression, decreasing overall protein synthesis, and enhancing degradation of misfolded proteins through distinct transmembrane sensor pathways.
Unfolded protein response (UPR)
This explains why proteins move through the cis, medial, and trans Golgi stacks rather than Golgi enzymes moving backward through the stacks.
constitutive secretion
This explains why glycolysis can continue in the absence of oxygen even though the citric acid cycle and oxidative phosphorylation cannot.
regeneration of NAD⁺ through fermentation
This explains why cyanide is lethal by stopping ATP production despite intact glycolysis and the citric acid cycle.
inhibition of the electron transport chain