Intracellular Compartments and Protein Transport

These flashcards cover key vocabulary and concepts related to intracellular compartments and protein transport.

Intracellular compartments

Membrane-enclosed structures that separate chemical processes in eukaryotic cells.

Membrane-enclosed organelles

Organelles that have a membrane to create private environments for biochemical reactions.

Cytosol

The liquid part of the cytoplasm where metabolic pathways occur.

Nucleus

The organelle that houses the cell's genetic material.

Endoplasmic reticulum (ER)

An organelle that synthesizes proteins and lipids.

Golgi apparatus

An organelle that modifies, sorts, and packages proteins and lipids.

Lysosome

An organelle that contains enzymes for intracellular degradation.

Endosome

A membrane-bound compartment involved in sorting endocytosed material.

Mitochondria

The organelles where ATP is synthesized via oxidative phosphorylation.

Chloroplasts

Organelles found in plant cells for photosynthesis.

Peroxisomes

Organelles involved in the oxidation of toxic molecules.

Signal sequences

Short peptide sequences that direct proteins to their proper locations.

Nuclear pores

Large protein complexes that span the nuclear envelope and regulate transport.

Nuclear lamina

A network of protein filaments providing structural support to the nucleus.

Nuclear Localization Sequence (NLS)

A sequence that directs protein transport into the nucleus.

Chaperones

Proteins that assist in the correct folding of other proteins.

ER signal sequence

A sequence that directs nascent proteins into the ER membrane.

Transmembrane proteins

Proteins that span the lipid bilayer of membranes.

Glycosylation

The addition of carbohydrate groups to proteins or lipids.

Disulfide bonds

Covalent bonds formed between cysteine residues to stabilize protein structure especially in rough environments.

Unfolded protein response (UFP)

Cellular response to an excess of unfolded proteins in the ER.

Vesicle formation

The process by which membrane-bound structures are created to transport materials.

Clathrin-coated vesicles

Vesicles that transport specific cargo molecules through endocytosis.

Adaptin

A protein that helps stabilize the attachment of clathrin to a developing vesicle.

Motor proteins

Proteins that transport vesicles along the cytoskeleton.

Rab proteins

Proteins that ensure vesicles fuse with the correct membrane.

SNAREs

Transmembrane proteins that facilitate vesicle docking and fusion.

Endocytosis

The process by which cells internalize substances.

Phagocytosis

The ingestion of large particles by cells.

Pinocytosis

The ingestion of fluids and small molecules by cells.

Receptor-mediated endocytosis

A selective form of endocytosis that increases efficiency of macromolecule uptake.

LDL

Low-density lipoproteins that transport cholesterol and are taken up by cells via endocytosis.

Lysosomal enzymes

Hydrolytic enzymes that digest macromolecules within lysosomes.

Autophagy

The process by which cells degrade and recycle their own components.

Exocytosis

The process by which cells release substances to the extracellular space.

Protein translocators

Proteins that assist in moving polypeptides into organelles.

Secretory pathway

The route by which proteins are secreted from the cell.

Constitutive secretion

Continuous release of substances from a cell without a specific signal.

Regulated secretion

Release of substances in response to specific signals.

Golgi cisternae

Flattened, membrane-bounded compartments of the Golgi apparatus.

Cytoskeleton

A network of fibers that helps maintain cell shape and facilitates transport.

Endomembrane system

A group of membranes and organelles that work together to modify, package, and transport lipids and proteins.

Protein synthesis

The process by which cells build proteins from amino acids.

Cell membrane

The lipid bilayer that surrounds a cell and regulates passage of substances.

Cytoplasmic streaming

The movement of the cytoplasm within the cell.

Molecular signals

Chemical signals that promote specific cellular responses.