Cell Structure and History (Vocabulary)

Vocabulary flashcards covering cell theory, cell types, organelles, and key plant vs. animal cell features from the lecture notes.

Cell

The basic unit of life; the building block of all organisms; contains cytoplasm, membrane, and genetic material.

Cell theory

Principles stating that all organisms are composed of cells, cells are the basic units of structure and function, and new cells arise from existing cells.

Prokaryotic cell

Cell type lacking internal membrane-bound organelles and a true nucleus; DNA is in a nucleoid region (bacteria).

Eukaryotic cell

Cell type with internal membranes and a true nucleus; generally larger and more complex (animal, plant, protist, fungi).

Nucleus

Control center of the cell that houses DNA; contains the nucleolus and is enclosed by the nuclear envelope.

DNA/Chromatin

Genetic material; chromatin is DNA packaged with proteins inside the nucleus.

Nucleolus

Nuclear substructure where ribosomal RNA is synthesized and ribosomes are assembled.

Nuclear envelope

Double membrane surrounding the nucleus with nuclear pores for transport.

Nuclear pore

Opening in the nuclear envelope that regulates transport between nucleus and cytoplasm.

Ribosome

Site of protein synthesis; small particles that can be free in cytosol or attached to rough ER.

Endoplasmic reticulum

Membrane network involved in protein and lipid synthesis and transport; rough ER has ribosomes, smooth ER does not.

Rough Endoplasmic Reticulum

ER studded with ribosomes; synthesizes and transports proteins.

Smooth Endoplasmic Reticulum

ER lacking ribosomes; synthesizes lipids, detoxification, and calcium storage.

Golgi apparatus

Stacks of membranes that process, modify, package, and ship proteins and lipids via vesicles.

Vesicle

Small membrane-bound sac used for transport of materials within or outside the cell.

Exocytosis

Process by which vesicles fuse with the plasma membrane to release contents outside the cell.

Endocytosis

Process by which cells take in material via vesicle formation from the plasma membrane.

Lysosome

Organelle containing digestive enzymes that break down waste and cellular debris.

Peroxisome

Vesicles with enzymes that neutralize hydrogen peroxide and perform other metabolic functions.

Mitochondrion

Site of cellular respiration; produces ATP; has inner folds called cristae.

Cristae

Folds of the inner mitochondrial membrane that increase surface area for energy production.

Cytoskeleton

Network of protein filaments that gives the cell shape, support, and enables movement.

Microfilaments

Thin actin filaments involved in cell movement and shape change.

Intermediate filaments

Mid-sized filaments providing mechanical support and cell integrity.

Microtubules

Hollow tubes that shape the cell and aid in transport and division (spindle fibers).

Centrioles

Cylindrical structures that organize microtubules during cell division (common in animal cells).

Centrosome

Microtubule organizing center near the nucleus; often contains a pair of centrioles.

Nucleoid

Region in prokaryotic cells where the chromosomal DNA is located; not membrane-bound.

Capsule

Slime layer outside the cell wall in some prokaryotes that aids adhesion and protection.

Pili

Hair-like structures on some bacteria that help with attachment to surfaces.

Plasmid

Small circular DNA molecule independent of the bacterial chromosome; often carries beneficial genes.

Cell membrane (plasma membrane)

Phospholipid bilayer that encloses the cell and regulates movement of substances in and out.

Cytosol

Liquid component of the cytoplasm; fluid in which organelles reside.

Chloroplast

Plastid in plant cells that conducts photosynthesis; contains chlorophyll.

Central vacuole

Large vesicle in plant cells that stores water and maintains turgor pressure.

Cell wall

Rigid layer outside the plasma membrane in plants (cellulose) that provides structure and protection.

Plasmodesmata

Channels through plant cell walls that connect adjacent plant cells for transport and communication.