Cellular Organelles and Structures Practice Flashcards

Comprehensive vocabulary flashcards covering the functions and importance of cellular organelles and structures as described in the lecture notes.

Cell Membrane

A selectively permeable barrier that regulates what enters and exits the cell, maintaining homeostasis and protecting the internal environment.

Chloroplasts

Organelles that convert solar energy into chemical energy (glucose) via photosynthesis, providing food/energy for plants and oxygen for aerobic organisms.

Ribosomes

Structures that synthesize proteins by translating mRNA sequences into amino acids, enabling structural support, enzymatic reactions, and signaling.

Capsule

A sticky, protective outer layer around certain bacteria that protects them from dehydration, environmental stress, and engulfment by immune cells (phagocytes).

Golgi Apparatus

An organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles, preventing toxic cellular buildup.

Cytoplasm

A jelly-like fluid (cytosol) filling the cell interior that holds organelles in place and serves as the site for metabolic reactions and molecular transport.

Centrioles

Structures that organize microtubules to form the mitotic spindle during cell division, ensuring accurate separation of chromosomes into daughter cells.

Cell Wall

A rigid layer outside the cell membrane in plants, fungi, and bacteria that provides structural support and prevents cells from bursting due to turgor pressure.

Mitochondria

The power plant of the cell that generates cellular energy in the form of $ATP$ through cellular respiration to drive biological processes.

Flagellum (Flagella)

Tail-like whip structures used to propel single-celled organisms or sperm cells forward, enabling motility to navigate toward nutrients or targets.

Smooth Endoplasmic Reticulum (SER)

An organelle that synthesizes lipids and phospholipids, metabolizes carbohydrates, and detoxifies chemicals and drugs.

Nucleoid

The region in prokaryotic (bacterial) cells that contains the circular DNA genome without a membrane envelope, holding instructions for growth and reproduction.

Lysosomes

The cell’s recycling and waste disposal system containing digestive enzymes to break down waste, foreign invaders, and worn-out cellular parts.

Large Central Vacuole

A plant-specific organelle that stores water, nutrients, and waste while maintaining turgor pressure to keep plant tissues rigid and upright.

Rough Endoplasmic Reticulum (RER)

A structure that folds and processes proteins synthesized by the ribosomes attached to its surface, preparing them for transport to the Golgi apparatus.

Fimbriae

Short, hair-like appendages on bacterial surfaces used for attachment to host tissues, surfaces, or other cells to form colonies and biofilms.

Nucleus

The control center and genetic vault of eukaryotic cells that encloses DNA and directs activities like growth, metabolism, and protein synthesis.

Cytoskeleton

A network of protein fibers (microfilaments, intermediate filaments, and microtubules) that maintains cell shape, anchors organelles, and facilitates transport.

Pilus

A hair-like structure on bacteria used for surface attachment and horizontal gene transfer (conjugation), such as spreading antibiotic resistance.

Vesicles

Small, membrane-bound sacs that act as a cellular delivery system, transporting proteins, nutrients, and waste between organelles or to the cell membrane.

Microtubules

Hollow tubulin cylinders that provide tracks for organelle movement, structural support, and the formation of spindle fibers, cilia, and flagella.