B260 Study Guide: Cell Biology Concepts and Terms

Cell

The basic structural, functional, and biological unit of all known living organisms.

Intermediate filaments

A component of the cytoskeleton that provides mechanical support to cells.

Microtubules

Cylindrical structures that are part of the cytoskeleton, involved in cell shape and transport.

Stem cell

A cell with the potential to develop into different cell types in the body.

Centrioles/centrosome

Organelles that play a key role in cell division and the organization of the mitotic spindle.

Cilia

Hair-like structures that extend from the surface of cells and are involved in movement.

Totipotent

Stem cells that can differentiate into any cell type, including embryonic and extraembryonic tissues.

Pluri(multi)potent

Stem cells that can differentiate into multiple cell types but not all.

Cell differentiation

The process by which a less specialized cell becomes a more specialized cell type.

Flagella

Long, whip-like structures that aid in cell movement.

Mitosis

A process of cell division that results in two genetically identical daughter cells.

Cell (plasma) membrane

The biological membrane that separates and protects the interior of all cells from the outside environment.

Phospholipid

A type of lipid molecule that is a major component of cell membranes.

Hydrophobic vs hydrophilic

Hydrophobic refers to molecules that repel water, while hydrophilic refers to molecules that attract water.

Active vs passive transport

Active transport requires energy to move substances against their concentration gradient, while passive transport does not.

Concentration gradient

The difference in the concentration of a substance across a space.

Prophase

The first stage of mitosis where chromosomes become visible and the nuclear envelope begins to disintegrate.

Metaphase

The stage of mitosis where chromosomes line up at the cell's equatorial plane.

Anaphase

The stage of mitosis where sister chromatids are pulled apart to opposite poles of the cell.

Telophase

The final stage of mitosis where the chromosomes de-condense and the nuclear envelope re-forms.

Solution = solute/solvent

A homogeneous mixture composed of a solute dissolved in a solvent.

Apoptosis

The process of programmed cell death that occurs in multicellular organisms.

Simple diffusion

The movement of molecules from an area of higher concentration to an area of lower concentration without energy.

Cytoplasm

The jelly-like substance within a cell that contains organelles.

Facilitated diffusion

The process of passive transport of molecules across a membrane via specific transmembrane proteins.

Osmosis

The diffusion of water across a selectively permeable membrane.

Hyper-, hypo-, isotonic

Terms describing the relative concentration of solutes in solutions: hypertonic (higher), hypotonic (lower), isotonic (equal).

Nucleus

The membrane-bound organelle that contains the cell's genetic material.

Nucleolus

A structure within the nucleus where ribosomal RNA is produced.

Filtration

The process of separating solids from fluids by adding a medium through which only the fluid can pass.

Nuclear pores

Protein complexes that cross the nuclear envelope and regulate the passage of molecules in and out of the nucleus.

Endocytosis

The process by which cells internalize substances from their external environment.

DNA

The molecule that carries the genetic instructions for life.

Chromatin

The complex of DNA and proteins that forms chromosomes within the nucleus.

Pinocytosis, phagocytosis, receptor-mediated endocytosis

Types of endocytosis: pinocytosis (cell drinking), phagocytosis (cell eating), receptor-mediated (specific uptake).

Exocytosis

The process by which a cell expels materials in vesicles that fuse with the plasma membrane.

ATP

A molecule that carries energy within cells.

Membrane potential (voltage) Vm

The difference in electric potential across a cell membrane.

Protein synthesis

The process by which cells generate new proteins.

Rough ER

Endoplasmic reticulum with ribosomes attached, involved in protein synthesis.

Smooth ER

Endoplasmic reticulum without ribosomes, involved in lipid synthesis and detoxification.

Golgi

An organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery.

Vesicle

A small membrane-bound sac that transports substances within a cell.

Lysosome

An organelle that contains digestive enzymes to break down waste materials and cellular debris.

Mitochondria

Organelles known as the powerhouse of the cell, generating ATP through respiration.

Ribosomes

Molecular machines that synthesize proteins by translating messenger RNA.

Cytoskeleton

A network of fibers that provides structural support and shape to the cell.

DNA to RNA = transcription

The process of copying a segment of DNA into RNA.

RNA to protein = translation

The process of decoding RNA to synthesize proteins.

mRNA vs tRNA

mRNA (messenger RNA) carries genetic information from DNA to ribosomes, while tRNA (transfer RNA) brings amino acids to ribosomes during protein synthesis.

Micro(actin)filaments

The thinnest filaments of the cytoskeleton, involved in cell shape and movement.