Topic 6

This set of flashcards covers key vocabulary from the lecture on cell and molecular biology, aiming to assist in understanding essential concepts related to cellular structure and function.

Cell

The basic structural and functional unit of every organism.

Prokaryotic Cell

Cells that have no nucleus, DNA in an unbound region called the nucleoid, and no membrane-bound organelles.

Eukaryotic Cell

Cells that have DNA in a nucleus bounded by a double membrane and membrane-bound organelles.

Plasma Membrane

A selective barrier that controls what goes into and out of the cell.

Ribosomes

Complexes made of ribosomal RNA and protein that are the sites of protein synthesis.

Endoplasmic Reticulum (ER)

An organelle accounting for more than half of the total membrane in many eukaryotic cells, with rough ER bearing ribosomes and smooth ER synthesizing lipids.

Golgi Apparatus

An organelle that modifies products of the ER, manufactures macromolecules, and sorts and packages materials into transport vesicles.

Lysosomes

Organelles that digest macromolecules and recycle organelles, functioning in phagocytosis and autophagy.

Vacuoles

Large vesicles derived from the ER and Golgi complex that perform various functions such as storage and maintaining turgor pressure in plant cells.

Mitochondria

The sites of cellular respiration that generate ATP and have similarities to bacteria, supporting the endosymbiont theory.

Chloroplasts

Organelles in plant cells that contain chlorophyll and are the sites of photosynthesis.

Peroxisomes

Specialized compartments that carry out metabolic functions, including the breakdown of fatty acids and detoxification.

Cytoskeleton

A network of fibers that support the cell, maintain its shape, and organize its structures and activities.

Extracellular Matrix (ECM)

A complex network of proteins and carbohydrates surrounding animal cells that influences cellular behavior and communication.

Cell Junctions

Structures that facilitate adherence, interaction, and communication between neighboring cells in tissues.

Nucleus

The organelle that contains most of the cell's genetic material and is often the most conspicuous organelle in a eukaryotic cell.

Nuclear Envelope

A double membrane that encloses the nucleus, separating its contents from the cytoplasm and perforated by pore structures.

Nuclear Pore

A protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm.

Cytoplasm

The contents of the cell bounded by the plasma membrane; in eukaryotes, the portion exclusive of the nucleus.

Rough Endoplasmic Reticulum (Rough ER)

A region of the endoplasmic reticulum that is studded with ribosomes and engages in protein synthesis and modification.

Smooth Endoplasmic Reticulum (Smooth ER)

A region of the endoplasmic reticulum that lacks ribosomes and functions in lipid synthesis, metabolism of carbohydrates, and detoxification of drugs and poisons.

Microtubule

Hollow rods about 25 nm in diameter that shape and support the cell and serve as tracks along which organelles equipped with motor proteins can move.

Microfilament (Actin Filament)

Thin solid rods built from molecules of actin that function in cell motility and bear tension (pulling forces) within the cytoskeleton.

Intermediate Filaments

Fibers intermediate in size between microtubules and microfilaments that specialize in bearing tension and fixing the position of certain organelles, such as the nucleus.

Glycosylation

The process by which a carbohydrate is covalently attached to an organic molecule, such as a protein or lipid.

Glycoprotein

A protein with one or more covalently attached carbohydrates, often found on the outer surface of plasma membranes or secreted by cells.

Golgi

An organelle consisting of stacks of flattened membranous sacs (cisternae) that modify, store, and route products of the ER and synthesize some products, notably non-cellulose carbohydrates.

Secretion

The process by which a cell releases substances into the extracellular space, typically via exocytosis.

Cisternae

The flattened, membrane-bound sacs that compose the Golgi apparatus and parts of the endoplasmic reticulum.

Endocytosis

The cellular uptake of biological molecules and particulate matter via the formation of vesicles from the plasma membrane.

Exocytosis

The cellular secretion of biological molecules by the fusion of vesicles with the plasma membrane.