This document defines 25 important vocabulary words related to cells and their structures. It describes key cellular components such as the electron microscope, virions, prokaryotic and eukaryotic cells, DNA, cell membranes, mitochondria, vacuoles, microtubules, microfilaments, ribosomes, and the endomembrane system including the endoplasmic reticulum, Golgi apparatus, and lysosomes. It also defines organelles specific to plant cells like the cell wall, chloroplasts, leucoplasts, and chromoplasts.

1. 25 vocab words
Definitions included
By: Tyler Winningham

2. Electron microscope
• A type of microscope that uses beams of
electrons to illuminate objects

3. virions
• Viral particles that have some similarities to
cells in that they contain genetic material and
structural proteins.

4. Prokaryotic cells
• A type of cell that contains generic material
that is not confined to a nucleus: the smallest
of all cells and generally considered to be
neither plant nor animal

5. Nucleoid region
• The region around the nucleus of a cell

6. DNA
• A genetic protein like nucleic acid on plant and
animal genes and chromosomes that control
inheritance

7. Eukaryotic cells
• A type of cell that contains genetic material
within the confines of a membrane-enclosed
nucleus; all plants and animals are made up of
eukaryotic cells.

8. Cell membrane
• Structure composed of proteins and lipids and
that contains the cytoplasm and nucleus.

9. diffusion
• A process by which molecules in solution pass
through the cell membrane from a region of a
higher concentration of molecules to a region
of lower concentration of molecules.

10. osmosis
• A process by which water passes through the
cell membrane from a region of high
concentration to a region of low
concentration; if the cell has relatively little
water inside, water is drawn from outside into
the cell membrane.

11. homeostasis
• The ability of an organism’s cell to remain
stable when conditions around it are
changing.

12. Cell wall
• A structure, found only in plant cells,
composed of cellulose and proving some
support for the entire plant.

13. mitochondria
• A peanut-shaped mitochondria that functions
to break down food nutrients and supply the
cell with energy

14. Vacuoles
• Organelles that serve as a storage
compartment for the cell

15. microtubules
• Organelles that are small, thin hollow tubes,
composed of protein, that give the cells their
shape and assist the movement of
chromosomes during cell division.

16. microfilaments
• A device that are fine fiber-like structures
composed of protein and help the cell move
by waving back and forth

17. ribosomes
• Organelles of very tiny structures that are the
sites where protein molecules are assembled
in the cell.

18. Endomembrane system
• The cell membrane, the endoplasmic
reticulum, the Golgi apparatus, the nucleus
membrane, and the vesicles.

19. Endoplasmic reticulum
• A large webbing or network of double
membranes that are positioned throughout
the cell whose function is to provide the
means for transporting material throughout
the cell

20. lumen
• An inner space within a cell where ions, such
as calcium, are stored and proteins are folded
and modified.

21. Golgi apparatus
• An organelle, shaped like a group of flat sacs
bundled together, whose function is to
remove water from the proteins and prepare
them for export from the cell.

22. Lysosomes
• Organelles that are the digestive units of DNA

23. plastids
• Bodies in plant cells that contain
photosynthesis pigment.

24. Chloroplasts
• Plastids that use the energy of the sun to
make carbohydrates and contain chlorophyll
that gives their green color.

25. Leucoplasts
• Plastids that provide storage for the cell and
are abundant in seeds, providing nutrients for
emerging plants and animals that eat the
seed.

26. Chromoplasts
• Plastids that manufacture pigments that give
fruit their color and also give leaves their
brilliant color in the fall.