Chapter 3: Cell Structure and Function Flashcards

Vocabulary flashcards covering key cellular anatomy, organelle functions, membrane transport mechanisms, cell cycle stages, cellular differentiation, and cell death based on Chapter 3 lecture outline.

Differentiated

Refers to cells that have developed specialized structural and functional characteristics.

Composite Cell

A hypothetical cell displaying the major components found in most cells: the nucleus, cytoplasm, and cell membrane.

Signal Transduction

The process by which the cell membrane allows a cell to receive and respond to incoming biological messages.

Phospholipid Bilayer

The structural framework of the cell membrane, consisting of water-soluble hydrophilic heads on the surfaces and water-insoluble hydrophobic tails forming the interior.

Cellular Adhesion Molecules (CAMs)

Proteins that guide cellular movement and enable cells to adhere to each other.

Selectins

A type of CAM that coats white blood cells and anchors them to capillary walls by providing friction.

Integrins

CAMs that direct white blood cells through capillary walls toward sites of infection.

Cytosol

The fluid portion of the cytoplasm in which organelles and membrane networks are suspended.

Ribosomes

Structures composed of protein and RNA that provide structural support and enzymatic activity to link amino acids in protein synthesis.

Rough Endoplasmic Reticulum (RER)

A membrane-bound network of sacs and canals studded with ribosomes, responsible for conducting protein synthesis.

Smooth Endoplasmic Reticulum (SER)

A membrane-bound network of sacs and canals lacking ribosomes, responsible for lipid synthesis.

Golgi Apparatus

Stacks of flattened, membranous sacs that refine, package, and deliver proteins synthesized on the RER.

Mitochondria

Membrane-bound, fluid-filled sacs known as the 'powerhouse of the cell' that extract energy from nutrients during cellular respiration to produce ATP.

Lysosomes

Small membranous sacs termed the 'garbage disposals' of the cell, containing enzymes that digest proteins, carbohydrates, nucleic acids, bacteria, and debris.

Peroxisomes

Membranous sacs containing enzymes that digest lipids, alcohol, and hydrogen peroxide.

Microfilaments

Tiny cytoskeletal rods composed of the protein actin that facilitate cellular movement, such as muscle contraction.

Microtubules

Larger cytoskeletal tubes made of the protein tubulin that maintain cell shape, move organelles, and form cilia, flagella, and centrioles.

Intermediate Filaments

Cytoskeletal structures composed of several proteins that support the nuclear envelope.

Centrosome

A central cytoplasmic structure near the nucleus consisting of two centrioles that produce spindle fibers to distribute chromosomes during cell division.

Cilia

Short, abundant, motile cell membrane extensions composed of microtubules that beat in a coordinated manner to move substances across cell surfaces.

Flagella

Long motile extensions of the cell membrane that cause an entire cell to move; in humans, only found on sperm cells.

Microvilli

Tiny cell membrane extensions composed of actin that function to increase surface area for absorption.

Inclusions

Non-essential chemical substances present only in certain cell types, such as melanin granules or fat.

Krabbe Disease

An organelle disease caused by the lack of a specific lysosomal enzyme, preventing myelin production for nerve cells and damaging the nervous system.

Adrenoleukodystrophy (ADL)

A disease caused by the lack of a protein in peroxisome membranes, leading to fatty acid accumulation that destroys myelin sheaths.

Nuclear Envelope

A double-layered membrane surrounding the nucleus containing nuclear pores that regulate the movement of substances between the nucleoplasm and cytoplasm.

Nucleolus

A dense nuclear body composed of RNA and protein that serves as the site of ribosome production.

Chromatin

A complex of DNA wound around proteins that stores genetic information for protein synthesis and forms chromosomes.

Diffusion

The passive movement of atoms, molecules, or ions from a region of higher concentration to lower concentration.

Facilitated Diffusion

Passive membrane transport using ion channels or carrier proteins for water-soluble substances that cannot cross the lipid bilayer.

Osmosis

The passive movement of water across a selectively permeable membrane through aquaporins toward a higher impermeant solute concentration.

Osmotic Pressure

The ability of osmosis to generate enough pressure to lift a volume of water, increasing as impermeant solute concentration rises.

Isotonic Solution

A solution with the same osmotic pressure as intracellular fluid, resulting in no net gain or loss of water by the cell.

Hypertonic Solution

A solution with a higher osmotic pressure than intracellular fluid, causing water to leave the cell and leading to cell shrinkage.

Hypotonic Solution

A solution with a lower osmotic pressure than intracellular fluid, causing water to enter the cell and leading to cell swelling or bursting.

Filtration

A passive movement process that forces smaller molecules through membranes by exerting pressure.

Active Transport

The ATP-requiring movement of substances across a cell membrane against a concentration gradient using carrier pumps.

Endocytosis

An active mechanism where large particles or substances enter a cell via a vesicle formed from the cell membrane.

Pinocytosis

A form of endocytosis in which the cell membrane invaginates to engulf droplets of liquid.

Phagocytosis

A form of endocytosis in which the cell membrane invaginates to engulf solid particles.

Receptor-Mediated Endocytosis

A selective endocytosis process where specific external molecules bind to membrane receptor proteins before being internalized in a vesicle.

Exocytosis

The process by which membrane-bound vesicles fuse with the cell membrane to release their contents outside the cell.

Transcytosis

A process combining receptor-mediated endocytosis and exocytosis to rapidly transport substances across a tightly connected cellular barrier.

Interphase

A non-dividing, highly active stage of the cell cycle where a cell grows, replicates DNA, and duplicates organelles.

Mitosis

The division of a somatic cell nucleus, consisting of prophase, metaphase, anaphase, and telophase.

Cytokinesis

The division of the cytoplasm during cell division, accomplished by an actin contractile ring forming a cleavage furrow.

Telomeres

Shortening chromosome tips that act as a mitotic clock to regulate the frequency of cell division.

Contact Inhibition

An external control mechanism that causes healthy cells to cease dividing when they become crowded.

Oncogenes

Abnormal, overexpressed forms of genes that regulate the cell cycle, leading to uncontrolled cell division and cancer.

Tumor Suppressor Genes

Genes that normally limit cell division; their inactivation or deletion removes control over mitosis and contributes to cancer.

Stem Cell

An undifferentiated cell capable of self-renewal or dividing to generate a specialized progenitor cell.

Progenitor Cell

A partially specialized, committed daughter cell of a stem cell that can divide to yield a restricted set of cell types.

Totipotent

Cells capable of specializing into any cell type, such as a fertilized egg or early embryonic cells.

Pluripotent

Cells capable of differentiating into a limited number of specific cell types.

Apoptosis

A programmed, orderly process of cell death that is a normal part of development and protective cellular removal.

Necrosis

Unprogrammed cell death resulting from severe tissue damage or injury.