Anatomy & Physiology: The Cell, Cellular Metabolism & Reproduction

Comprehensive vocabulary flashcards covering cell structure, organelles, transport mechanisms across the cell membrane, and cell division processes (mitosis and meiosis).

Active Transport

A transport process in which solutes move from areas of lesser to greater concentration, requiring energy in the form of ATP.

Cilia

Hair-like processes on the surface of the cell that propel materials across a surface.

Cytoplasm

Gel-like substance surrounding the nucleus and filling the cell, consisting of cytosol and organelles.

Deoxyribonucleic Acid (DNA)

A large polymer of a nucleotide that carries the genetic information of a cell.

Diffusion

A passive transport mechanism involving the movement of particles or solutes from an area of higher to lower concentration.

Endocytosis

A form of vesicular transport that brings substances into the cell by forming a vesicle from the plasma membrane.

Exocytosis

A form of vesicular transport where membrane-bound secretory vesicles fuse with the cell membrane to release substances outside the cell.

Facilitated Diffusion

A carrier-mediated transport process that moves substances across the cell membrane from an area of higher to lower concentration without requiring metabolic energy in the form of ATP.

Filtration

A transport process in which water and dissolved particles are forced across a membrane from an area of higher to lower pressure.

Golgi Apparatus

An organelle composed of flattened, membranous sacs that modifies protein structure and packages proteins in secretory vesicles.

Hydrostatic Pressure

The pressure exerted by water, such as the weight of a water column.

Hypertonic Solution

A solution that contains a higher concentration of solutes compared to the fluid within the cell, causing water to flow out of the cell and leading to cell shrinkage (crenation).

Hypotonic Solution

A solution that contains a lower concentration of solutes compared to the fluid within the cell, causing water to enter the cell and leading to cell swelling or bursting (lysis).

Isotonic Solution

A solution in which the solute concentration is equal to that inside the cell, resulting in no net water movement and normal cell shape.

Microvilli

Folds of the cell membrane that greatly increase the surface area of a cell to facilitate absorption.

Mitochondria

Bean-shaped organelles composed of a smooth outer membrane and a folded inner membrane (cristae) that serve as the site of aerobic respiration and major site of ATP synthesis.

Mitosis

A type of cell division in which a mother cell splits into two identical daughter cells, each containing a diploid set of $23$\text{ pairs of chromosomes}.

Nucleus

The cell's control center containing DNA and nucleoli, serving as the site for RNA synthesis and ribosomal subunit assembly.

Organelles

Structures within the cell that perform specific tasks in cellular metabolism.

Osmosis

A passive transport mechanism involving the diffusion of water down its concentration gradient across a selectively permeable membrane from an area of higher water concentration to lower water concentration.

Osmotic Pressure

The force required to prevent the movement of water across a selectively permeable membrane as a result of osmosis.

Passive Transport

Transport mechanisms across cell membranes that do not require cellular energy, including diffusion, osmosis, and facilitated diffusion.

Phagocytosis

A form of endocytosis in which large particles, such as bacteria, viruses, or cell debris, are trapped in the plasma membrane and brought into the cell ("cell eating").

Pinocytosis

A form of endocytosis in which fluid and dissolved particles are trapped in small vesicles formed by the plasma membrane and brought into the cell ("cell drinking").

Plasma Membrane

The external boundary of the cell made of a lipid bilayer of phospholipids and cholesterol with floating proteins, regulating substance exchange via selective permeability.

Polymer

A large molecule consisting of many smaller molecules joined in sequence.

Ribonucleic Acid (RNA)

A nucleotide that assists in protein synthesis.

Ribosomes

Granules of protein and RNA that serve as the site of protein synthesis, found free-floating in cytosol or attached to the rough endoplasmic reticulum.

Cell Metabolism & Energy Use

One of the main functions of a cell, involving chemical processes during metabolism that provide energy for muscle contraction and heat production.

Synthesis of Molecules

A main function of cells in which they synthesize proteins, nucleic acids, and lipids that determine the structural and functional characteristics of the cell.

Cytosol

The intracellular fluid portion of cytoplasm consisting of water and dissolved ions, proteins, amino acids, fatty acids, ATP, and gases.

Rough Endoplasmic Reticulum

A membrane system continuous with the nuclear envelope and studded with ribosomes, serving as a site for synthesizing glycoproteins and phospholipids.

Smooth Endoplasmic Reticulum

A membrane system without ribosomes that synthesizes fatty acids and steroids, detoxifies harmful substances, and stores ionized calcium.

Secretory Vesicle

A membrane-bound vesicle formed by the Golgi apparatus that contains materials produced in the cell to be secreted by exocytosis.

Peroxisomes

Small, membrane-bound vesicles containing enzymes that break down fatty acids, amino acids, and toxic hydrogen peroxide into water and oxygen.

Cristae

Folds of the inner mitochondrial membrane where cellular respiration occurs to convert food into ATP.

Cytoskeleton

A network of protein elements—microfilaments, intermediate filaments, and microtubules—that holds organelles in place and aids cell shape and movement.

Microfilaments

Small protein strands of the cytoskeleton that provide mechanical support, generate force for movement, anchor plasma membrane proteins, and support microvilli.

Intermediate Filaments

Cytoskeletal protein strands sized between microfilaments and microtubules that hold organelles in place and attach cells to one another.

Microtubules

Long, hollow protein tubes that support cytoplasm, determine cell shape, assist in cell division, and form structural components of cilia, flagella, and centrioles.

Centrosome

A structure located near the nucleus containing a pair of centrioles and pericentriolar material that builds microtubules in non-dividing cells and forms the mitotic spindle during cell division.

Centrioles

Cylindrical organelles composed of nine microtubule triplets that facilitate chromosome movement during cell division.

Intracellular Fluid (ICF)

The fluid compartment located inside the cell containing enzymes, glycogen, and potassium ions.

Extracellular Fluid (ECF)

The fluid compartment located outside the cell, subdivided into plasma, interstitial fluid, lymph, and cerebrospinal fluid.

Concentration Gradient

The difference in concentration of a substance between two areas.

Leak Channels

Membrane channels that constantly allow ions to pass through the cell membrane.

Gated Channels

Membrane channels that limit ion movement across the cell membrane by opening and closing.

Sodium-Potassium Pump

An active transport mechanism powered by ATP that moves three $\text{Na}^+$ out of cells and two $\text{K}^+$ into cells to establish concentration gradients essential for resting membrane potential.

Secondary Active Transport

A transport mechanism where the active transport of one substance (e.g., $\text{Na}^+$) establishes a concentration gradient whose diffusion provides energy to move a second substance (e.g., glucose) across the membrane.

Interphase

The growth period before a dividing cell enters mitosis, taking $20\text{ to }22\,\text{hours}$ and occupying about $90\%$ of the normal cell cycle time.

Prophase

The first phase of mitosis where chromatin condenses into chromosomes (each with two sister chromatids joined at a centromere), centrioles move to opposite poles, and the nuclear envelope dissolves.

Metaphase

The second phase of mitosis where spindle fibers attach to centromeres and chromosomes align along the center of the cell.

Anaphase

The third phase of mitosis where centromeres divide and spindle fibers pull newly formed chromosomes to opposite poles of the cell.

Telophase

The final phase of mitosis where a new nuclear envelope develops around each set of daughter chromosomes, spindle fibers disappear, and cytoplasm divides to form two identical daughter cells.

Meiosis

Specialized cell division in gametes where a parent cell undergoes two rounds of division without intervening DNA replication, producing four genetically unique haploid cells.

Tetrads

Tight groups of paired homologous chromosomes formed during prophase I of meiosis.

Crossing Over

The exchange of genetic material between non-sister chromatids during prophase I of meiosis, creating genetic variation.

Haploid

Having half the normal number of chromosomes (one set), characteristic of gametes produced by meiosis.

Diploid

Having a complete set of paired chromosomes ($23$\text{ pairs in humans}), characteristic of somatic cells and daughter cells produced by mitosis.