Lab 2 - Cell Components and Cell Cycle

Vocabulary flashcards covering cell organelles, membrane structure, passive and active transport mechanisms, cell cycle, mitosis, stem cells, and cell death from BIO-111 Lab 2.

Composite Cell

A model cell showing the major structures and components found in most cells, comprising the nucleus, cytoplasm, and cell membrane.

Cytoplasm

The cellular region between the nucleus and cell membrane, consisting of cytosol and suspended organelles.

Cytosol

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

Cell Membrane

The outer, flexible, and selectively permeable boundary of a cell that maintains cell integrity and regulates the passage of substances.

Phospholipid Bilayer

The basic framework of the cell membrane composed of water-soluble (hydrophilic) heads on the surfaces and water-insoluble (hydrophobic) tails in the interior.

Cellular Adhesion Molecules (CAMs)

Membrane proteins, such as selectins and integrins, that guide cells on the move and enable cells to stick to each other.

Selectins

Cellular adhesion molecules that coat white blood cells and anchor them to capillary walls by providing friction.

Integrins

Cellular adhesion molecules that bind to adhesion receptor proteins and direct white blood cells through capillary walls toward infection sites.

Ribosomes

Structures composed of protein and RNA, found free in the cytoplasm or attached to the rough ER, that link amino acids during protein synthesis.

Endoplasmic Reticulum (ER)

A complex system of membrane-bound sacs, canals, and vesicles that functions as a tubular transport network within the cell.

Rough Endoplasmic Reticulum (RER)

Endoplasmic reticulum studded with ribosomes on its outer surface that conducts protein synthesis.

Smooth Endoplasmic Reticulum (SER)

Endoplasmic reticulum lacking ribosomes that conducts lipid synthesis.

Golgi Apparatus

A stack of flattened membranous sacs that refines, packages, and delivers proteins produced on the rough ER.

Mitochondria

Membrane-bound, fluid-filled sacs known as the powerhouses of the cell that conduct cellular respiration to extract energy from nutrients and produce ATP.

Lysosomes

Small membranous sacs containing digestive enzymes that break down proteins, carbohydrates, nucleic acids, bacteria, debris, and worn-out cell parts.

Peroxisomes

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

Microfilaments

Cytoskeletal tiny rods composed of the protein actin that have the smallest diameter among cytoskeletal filaments and provide cellular movement.

Microtubules

Cytoskeletal tubes composed of the protein tubulin that have the largest diameter among cytoskeletal filaments and maintain cell shape while forming cilia, flagella, and centrioles.

Intermediate Filaments

Cytoskeletal structures with diameters between microfilaments and microtubules that support the nuclear envelope.

Centrosome

A structure located in the cytoplasm near the nucleus consisting of two cylindrical centrioles that produce spindle fibers during cell division.

Cilia

Short, abundant, motile extensions of the cell membrane containing microtubules that beat back and forth to propel fluids or mucus across cell surfaces.

Flagella

Long motile extensions of the cell membrane, such as the tail of a sperm cell, that move an entire cell.

Microvilli

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

Inclusions

Chemicals stored in certain cell types that are not necessary for cell survival, such as melanin granules or fat droplets.

MELAS

A disease resulting from a mutant gene in mitochondrial DNA that prevents the body from extracting maximum energy from nutrients.

Krabbe Disease

A condition caused by the inability to produce one lysosomal enzyme, preventing myelin production and damaging the nervous system.

Adrenoleukodystrophy (ALD)

A disorder caused by the absence of a protein in peroxisomal membranes, leading to fatty acid accumulation that destroys nerve cell myelin sheaths.

Nuclear Envelope

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

Nucleolus

A dense body of RNA and protein within the cell nucleus that serves as the site of ribosome assembly.

Chromatin

Nuclear material consisting of DNA wound around proteins that condenses to form chromosomes and stores genetic information for protein synthesis.

Cell Nucleus

Organelle surrounded by a nuclear envelope that contains genetic material and directs cell activities.

Diffusion

Passive movement of atoms, molecules, or ions down a concentration gradient from a region of higher concentration to a region of lower concentration.

Facilitated Diffusion

Passive transport of water-soluble substances across a cell membrane using transmembrane channels or protein carriers without consuming ATP.

Osmosis

Passive movement of water across a selectively permeable membrane toward a region of higher impermeant solute concentration.

Osmotic Pressure

The pressure generated by osmosis required to lift a volume of water, which increases with higher impermeant solute concentration.

Isotonic Solution

A solution with the same osmotic pressure as intracellular fluid, resulting in no net water movement into or out of cells.

Hypertonic Solution

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

Hypotonic Solution

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

Filtration

A passive transport mechanism that uses hydrostatic pressure to force small molecules and water through membranes while retaining larger particles.

Active Transport

Movement of substances across a membrane against a concentration gradient using carrier proteins and cellular energy (ATP).

$\text{Na}^+-\text{K}^+$ ATPase Pump

An active transport carrier protein that pumps 3 $\text{Na}^+$ ions out of the cell and 2 $\text{K}^+$ ions into the cell using ATP energy.

Secondary Active Transport

Transport mechanism where a carrier protein uses an existing ion concentration gradient to move another substance across the membrane without direct use of ATP.

Endocytosis

Active transport process in which the cell membrane invaginates to engulf external substances within a membrane-bound vesicle.

Pinocytosis

A form of endocytosis in which the cell membrane engulfs small droplets of liquid from the extracellular space.

Phagocytosis

A form of endocytosis in which the cell membrane engulfs solid particles to form a vesicle known as a phagosome.

Receptor-Mediated Endocytosis

Selective endocytosis in which target molecules (ligands) bind to specific membrane receptors before being taken into the cell in a vesicle.

Exocytosis

Transport mechanism in which intracellular vesicles fuse with the cell membrane to release contents into the extracellular space.

Transcytosis

Rapid transport mechanism combining receptor-mediated endocytosis and exocytosis to move substances across a cellular barrier.

Cell Cycle

The series of changes a cell undergoes from its formation until it divides, comprising interphase, mitosis, and cytokinesis.

Interphase

The active period of the cell cycle in which the cell grows, conducts normal functions, replicates DNA during S phase, and duplicates organelles.

Mitosis

Division of the cell nucleus (karyokinesis) into two identical nuclei, consisting of prophase, metaphase, anaphase, and telophase.

Cytokinesis

Division of the cell cytoplasm into two daughter cells, beginning in anaphase and ending in telophase.

Cleavage Furrow

The constriction formed by a contractile ring of actin filaments pinching the cytoplasm during cytokinesis.

Telomeres

Chromosome tips that shorten with each nuclear division, acting as a mitotic clock to limit cell division.

Contact Inhibition

The natural restriction where healthy cells stop dividing when they become crowded.

Oncogenes

Overexpressed, abnormal forms of cell-cycle-controlling genes that drive uncontrolled cell division.

Tumor Suppressor Genes

Genes that normally limit or regulate mitosis; their inactivation or deletion removes control over cell division.

Stem Cell

An undifferentiated cell capable of self-renewal or dividing to yield a progenitor cell and specializing into various cell types.

Progenitor Cell

A partially specialized, committed cell descended from a stem cell that can differentiate into a limited number of cell types.

Totipotent

The ability of a cell (such as a fertilized egg or early embryonic cell) to differentiate into any cell type.

Pluripotent

The ability of a cell to differentiate into a restricted or limited number of cell types.

Apoptosis

Programmed, stepwise cell death that occurs naturally during development and removes damaged cells.

Necrosis

Unplanned or abnormal cell death resulting from severe cell damage or injury.