Cell Structure and Function: Subcellular Components and Compartmentalization

Vocabulary practice flashcards covering cell classifications, eukaryotic and prokaryotic cell structures, compartmentalization, endomembrane organelles, and unique plant and animal organelles.

Cells

The basic structural and functional units of every organism, which are all bound by a plasma membrane, contain cytosol, contain chromosomes, and contain ribosomes.

Prokaryotes

Cells belonging to the domains Bacteria and Archaea that have their DNA located in the nucleoid region, lack membrane-bound organelles, and are generally smaller in size than eukaryotes.

Eukaryotes

Cells comprising protists, fungi, animals, and plants that store their DNA inside a nucleus and contain membrane-bound organelles.

Organelles

Membrane-bound structures within eukaryotic cells that perform specialized functions; classified into endomembrane organelles and energy organelles.

Endomembrane Organelles

A group of eukaryotic organelles consisting of the nuclear envelope, endoplasmic reticulum, Golgi complex, lysosomes, vesicles/vacuoles, and plasma membrane.

Energy Organelles

The category of eukaryotic cellular organelles specialized for energy processes, consisting of mitochondria and chloroplasts.

Compartmentalization

The organization of different metabolic reactions into distinct organelles, which increases surface area for reactions and prevents interfering reactions from occurring in the same location.

Plant-Specific Cell Components

Cellular structures present in plant cells but absent in animal cells: chloroplasts, central vacuole, cell wall, and plasmodesmata.

Animal-Specific Cell Components

Cellular structures present in animal cells but absent in plant cells: lysosomes, centrosomes, and flagella.

Nucleus

The organelle containing chromosomes (genetic information), enclosed by a double-membraned nuclear envelope equipped with pores that regulate the entry and exit of cellular materials.

Nucleolus

A dense region of the nucleus where ribosomal RNA ($\text{rRNA}$) is synthesized and combined with proteins to form large and small subunits of ribosomes.

Ribosomes

Non-membrane-bound complexes comprised of ribosomal RNA and protein that synthesize proteins by translating messages found on $\text{mRNA}$ into the primary structure of polypeptides.

Free Ribosomes

Ribosomes located in the cytosol whose synthesized proteins generally function only within the cytosol, such as enzymes.

Bound Ribosomes

Ribosomes attached to the endoplasmic reticulum or nuclear envelope whose synthesized proteins can be secreted from the cell via transport vesicles.

Endoplasmic Reticulum (ER)

A network of membranous sacs and tubes that synthesizes membranes and compartmentalizes the cell to keep proteins formed in the rough ER separate from those made by free ribosomes.

Rough ER

The portion of the endoplasmic reticulum studded with ribosomes on its membrane that ensures newly formed proteins are folded or modified correctly.

Smooth ER

The portion of the endoplasmic reticulum that contains no ribosomes; functions in synthesizing lipids, metabolizing carbohydrates, and detoxifying the cell.

Cisternae

Flattened, separate membranous sacs forming the Golgi complex that isolate its contents from the cytosol.

Cis Face

The receiving side of the Golgi complex that accepts transport vesicles containing materials sent from the endoplasmic reticulum.

Trans Face

The shipping side of the Golgi complex that sends vesicles back out into the cytosol to other locations or to the plasma membrane for secretion.

Golgi Complex

An organelle composed of flattened cisternae that receives, modifies, sorts, tags, and packages materials into new transport vesicles exiting via exocytosis.

Lysosomes

Membranous sacs filled with hydrolytic enzymes that hydrolyze macromolecules in animal cells and conduct autophagy to recycle cellular organic components.

Autophagy

The cellular process in which lysosomes recycle the cell's own organic materials, allowing the cell to renew itself.

Peroxisomes

Membrane-bound metabolic compartments that catalyze reactions producing $H_2O_2$, which their internal enzymes then break down into water ($H_2O$).

Vacuoles

Large, selectively transporting vesicles that stem directly from the endoplasmic reticulum and Golgi complex.

Food Vacuole

A type of vacuole formed through phagocytosis (cell eating) that fuses with lysosomes to digest engulfed nutrients.

Contractile Vacuole

A specialized type of vacuole that maintains optimal water levels inside cells.

Central Vacuole

A large plant-specific vacuole containing inorganic ions and water that plays a crucial role in maintaining turgor pressure.