prokaryotic cell: a simple, unicellular organism that lacks a membrane-bound nucleus and organelles, such as bacteria and archaea.

cell membrane: a semi-permeable layer that surrounds the cell, controlling the movement of substances in and out.

pilus: hair-like structures on the surface of prokaryotic cells that help in attachment to surfaces and the transfer of genetic material.

cell wall: a rigid outer layer found in plants, bacteria, fungi, and some protists that provides structure and protection.

flagellum: a whip-like structure that helps with cell movement, commonly found in bacteria and sperm cells.

nucleoid: the region in a prokaryotic cell where the cell’s genetic material (DNA) is located, not enclosed by a membrane.

plasmid: small, circular DNA molecules found in prokaryotic cells that can replicate independently of the chromosomal DNA.

cytoplasm: the jelly-like substance within the cell that contains organelles and is the site of many metabolic reactions.

ribosome: small structures that synthesize proteins by translating messenger RNA into polypeptides.

hyaloplasm: the clear, fluid portion of the cytoplasm where organelles are suspended.

eukaryotic cell: a complex cell with membrane-bound organelles, including a nucleus, found in plants, animals, fungi, and protists.

plasmodesma: channels that connect plant cells, allowing for transport and communication between them.

vacuole: a large, membrane-bound organelle in plant cells that stores nutrients, waste products, and maintains turgor pressure.

tonoplast: the membrane that surrounds the central vacuole in plant cells, regulating the movement of ions and molecules.

plastid: a type of organelle in plant cells responsible for functions like photosynthesis, storage, and pigment production.

chloroplast: a type of plastid that contains chlorophyll and is the site of photosynthesis in plant cells.

leucoplast: non-pigmented plastids in plant cells that store starch, oils, and proteins.

chromoplast: plastids that produce and store pigments other than chlorophyll, responsible for the colors in fruits and flowers.

golgi complex: a membrane-bound organelle that modifies, packages, and transports proteins and lipids for secretion or use within the cell.

endoplasmic reticulum: a network of membranes involved in protein and lipid synthesis, with rough ER being studded with ribosomes and smooth ER lacking them.

mitochondrion: the powerhouse of the cell, where cellular respiration occurs to produce ATP, the cell’s energy currency.

lysosome: membrane-bound organelles containing enzymes that digest and break down waste materials and cellular debris.

nucleus: the membrane-bound organelle in eukaryotic cells that houses the genetic material (DNA).

nuclear envelope: a double membrane that surrounds the nucleus, separating it from the cytoplasm and regulating molecular traffic through nuclear pores.

nuclear pore: openings in the nuclear envelope that allow the passage of molecules like RNA and proteins between the nucleus and cytoplasm.

nucleolus: a dense region within the nucleus where ribosomal RNA (rRNA) is synthesized and ribosome assembly begins.

chromatin: a complex of DNA and proteins in the nucleus that condenses to form chromosomes during cell division.

centriole: cylindrical structures in animal cells that play a role in organizing microtubules during cell division.