Cell Biology Flashcards

Flashcards covering key vocabulary terms from cell biology lectures.

Plasma Membrane

The outer boundary of a cell that separates the internal environment (cytoplasm) from the external environment. Functions as a selective barrier, regulating the passage of substances in and out of the cell.

Selective Barrier

The function of the plasma membrane, allowing only certain substances to pass through while restricting others. Facilitated by channels and transporters within the membrane.

Surface Area to Volume Ratio

The ratio that is critical for cells to maintain in order to support metabolic functions. A larger surface area allows for more efficient exchange of materials.

Prokaryotic Cell

A simpler cell type that lacks membrane-bound organelles and a true nucleus. Characterized by a nucleoid region where DNA is located.

Eukaryotic Cell

A more complex cell type with membrane-bound organelles, including a nucleus, that compartmentalize cellular functions.

Organelle

A specialized subunit within a cell that has a specific function, membrane bound in eukaryotic cells.

Ribosomes

Protein-making factories found in both prokaryotic and eukaryotic cells. Synthesize polypeptides.

Endoplasmic Reticulum (ER)

An organelle involved in protein and lipid synthesis. The rough ER (RER) has ribosomes attached, while the smooth ER (SER) does not.

Golgi Apparatus

An organelle that processes and packages proteins and lipids, often receiving materials from the endoplasmic reticulum.

Chloroplast

An organelle found in plant cells where photosynthesis occurs, converting light energy into chemical energy in the form of sugars.

Central Vacuole

A large, fluid-filled organelle in plant cells that stores water, ions, and other molecules. Enclosed by a membrane called the tonoplast.

Tonoplast

The membrane that surrounds the central vacuole in plant cells, regulating the movement of substances into and out of the vacuole.

Cell Wall

A rigid outer layer found in plant cells that provides protection, maintains cell shape, and prevents excessive water uptake.

Cytoskeleton

A network of protein fibers within the cytoplasm that provides structural support, organizes cellular activities, and facilitates movement.

Cytoplasm

The entire region of the cell between the nucleus and the plasma membrane, consisting of cytosol and organelles.

Cytosol

The liquid component of the cytoplasm, excluding the organelles. It is a gel-like substance where many metabolic reactions occur.

Microfilaments

A type of cytoskeletal fiber composed of actin. Involved in cell shape, movement, and muscle contraction.

Intermediate Filaments

A type of cytoskeletal fiber with a diameter intermediate between microfilaments and microtubules. Provides structural support and stability.

Microtubules

A type of cytoskeletal fiber composed of tubulin subunits. Involved in cell shape, movement, and chromosome segregation during cell division.

Actin

A globular protein that polymerizes to form microfilaments, a key component of the cytoskeleton.

Tubulin

The protein that polymerizes to form microtubules, a major component of the cytoskeleton.