BIO 111 - Cell Structure & Function Flashcards

Vocabulary practice flashcards covering cellular structure, plasma membrane function, organelles, cell division, and chromosome dynamics from BIO 111 lecture material.

Fluid Mosaic Model

A structural model describing the plasma membrane as a dynamic arrangement of proteins floating within a continuous sea of lipids.

Lipid Bilayer

The basic structural framework of the plasma membrane, composed of two back-to-back layers consisting of phospholipids, cholesterol, and glycolipids.

Integral Proteins

Membrane proteins that extend into or completely across the lipid bilayer, positioned among the hydrophobic fatty acid tails.

Peripheral Proteins

Membrane proteins attached strictly to the inner or outer surfaces of the membrane that can be detached without destroying structural integrity.

Ion Channel Protein

An integral membrane protein that forms a water-filled pore allowing specific ions to pass through the plasma membrane.

Transporter Protein

An integral membrane protein that binds a specific substance, undergoes a conformational shape change, and moves the molecule across the membrane.

Receptor Protein

An integral membrane protein that acts as a cellular recognition site by binding a specific external substance (ligand) to alter cell function.

Cell Identity Marker

A membrane glycoprotein (such as an MHC protein) that allows a cell to recognize other similar cells and distinguish self from non-self.

Linker Protein

A membrane protein that anchors filaments inside and outside the cell membrane to provide structural stability, maintain cell shape, or facilitate cell movement.

Microvilli

Non-motile microscopic extensions of the plasma membrane that function to increase total cell surface area.

Ribosomes

Cellular structures composed of large and small subunits that serve as the primary sites of protein synthesis.

Rough Endoplasmic Reticulum

A membranous organelle network studded with attached ribosomes where proteins are manufactured and chemically modified.

Smooth Endoplasmic Reticulum

A membranous organelle network devoid of attached ribosomes that functions in lipid synthesis.

Golgi Apparatus

An organelle consisting of stacked cisternae that modifies, packages, and distributes proteins and lipids for internal cell use or secretion.

Lysosome

A membrane-bound digestive organelle formed by the Golgi apparatus that fuses with endocytic vesicles to degrade internalized materials.

Peroxisomes

Membrane-bound organelles smaller than lysosomes that contain enzymes to breakdown fatty acids and amino acids, yielding hydrogen peroxide as a byproduct.

Proteasomes

Large protein complexes in the cytoplasm containing enzymes that systematically break down and recycle unneeded or damaged cellular proteins.

Mitochondria

Double-membrane-bound organelles containing their own DNA that serve as the principal sites of ATP synthesis.

Cytoskeleton

A complex network composed of microtubules, microfilaments, and intermediate filaments that maintains cell shape, provides structural support, and aids cell division and movement.

Interphase

The phase of the cell life cycle between divisions consisting of $G_1$, $S$, and $G_2$ stages during which normal metabolism, growth, and DNA replication take place.

$G_0$ Phase

A specialized non-dividing state entered by cells that will never undergo cell division again.

Sister Chromatids

Two identical copies of a replicated chromosome produced during the $S$ phase that remain bound together at the centromere prior to nuclear division.

Centromere

The centralized structural region of a chromosome that physically connects two identical sister chromatids.

Mitosis

The nuclear division process comprising prophase, metaphase, anaphase, and telophase that yields two genetically identical nuclei.

Cytokinesis

The physical cleavage and division of the cellular cytoplasm into two separate daughter cells.

Maturation Promoting Factor (MPF)

A regulatory molecular complex that induces cell division.

Apoptosis

Genetically programmed cell death triggered by internal or external signals activating cell-suicide pathways.

Necrosis

Uncontrolled pathological cell death resulting directly from physical trauma or injury.

Tumor-Suppressor Genes

Genes encoding proteins that normally inhibit cell division to prevent uncontrolled cellular growth and cancer formation.

Meiosis

A two-stage reproductive cell division process (Meiosis I and Meiosis II) that produces four haploid daughter cells, each containing 23 chromosomes.