Unit 4

Light Microscope

Uses light as an energy source, with mirrors directing the light to your eyes and lenses used to enlarge and focus the image.

Electron Microscope

Uses electricity as an energy source, with magnets directing the flow of electrons for viewing. Can be scanning (e- reflect off the specimen for 3D viewing) or transmission (e- flow through providing an internal structure).

Fluid Mosaic Model

Describes the structure of the cell membrane, with the fluid component consisting of phospholipids and cholesterol, and the mosaic component consisting of proteins. Phospholipids create flexible bilayers that act as a water barrier, while cholesterol regulates the fluidity of the cell membrane.

Prokaryotic Cell

A type of cell that lacks a nucleus and membrane-bound organelles. Contains structures such as cytoplasm, bacterial chromosome, nucleoid, ribosomes, plasmid, cell membrane, cell wall, capsule, flagella, fimbriae, and extracellular fluid.

Cytoplasm

Gel-like fluid (cytosol) that contains chemicals (proteins) and cell structures (ribosomes) in the inner region of the cell, contained by the cell membrane.

Bacterial Chromosome

Circular DNA that contains genetic information in prokaryotic cells.

Nucleoid

Region of the cytoplasm where the bacterial chromosome is located in prokaryotic cells.

Ribosomes

Structures responsible for protein synthesis in the cell.

Plasmid

Extra small pieces of DNA that provide additional functions to prokaryotic cells, such as antibiotic resistance, motility, production of a capsule, and fertility.

Pathogenic

Ability to cause infection or disease.

Cell Wall

Structure made up of a mixture of carbohydrates and proteins called peptidoglycan, providing structure and shape to prokaryotic cells.

Capsule

A protective layer that may or may not be present in prokaryotic cells, allowing attachment to surfaces and resistance to digestion by white blood cells.

Flagella

Proton-based structures extending from the cell membrane, allowing cells to move by rotation.

Fimbriae

Proton-based structures extending from the cell membrane for attachment to surfaces.

Extracellular Fluid

Fluid on the outside of the cell.

Eukaryotic Cells

Cells that have a nucleus and membrane-bound organelles. They have compartmentalization, which is the process of creating compartments closed off within the cell.

Vacuole

Large vesicles with specialized functions, such as food vacuoles for phagocytosis and central vacuoles for water storage and chemical storage.

Endomembrane System

A system of organelles involved in the synthesis, modification, and transport of proteins and lipids. Includes the nucleus, endoplasmic reticulum, Golgi apparatus, and lysosomes.

Nucleus

Controls the function of the cell and stores genetic material. Contains the nucleolus, chromatin, nucleoplasm, inner nuclear membrane, outer nuclear membrane, nuclear pores, proton complex, ribosomes, and nuclear envelope.

Ribosomes

Structures responsible for protein synthesis in the cell. Can be bound (attached to the membrane) or free (located in the cytoplasm).

Endoplasmic Reticulum (ER)

A network of membrane tubules involved in the synthesis, modification, and transport of proteins and lipids. Can be smooth (involved in lipid synthesis and detoxification) or rough (covered with bound ribosomes for protein synthesis).

Golgi Apparatus

Receives, modifies, sorts, and packages chemicals from other organelles for transport to their final destination. Can send chemicals to other organelles, the cell membrane, or for export out of the cell.

Lysosome

Specialized vesicles filled with hydrolytic enzymes for breaking down proteins, carbohydrates, lipids, and nucleic acids. Involved in processes such as phagocytosis and autophagy.

Mitochondrion

Generates energy in the form of ATP through cellular respiration. Found in all eukaryotic cells.

Chloroplast

Harvests light to produce food through photosynthesis. Found in plants and algae, containing chlorophyll to absorb light and provide energy to the chloroplast.

Cytoskeleton

The skeleton of the cell located in the cytosol, providing structure and support. Includes components such as flagella, cilia, microtubules, and intermediate filaments.

Extracellular Matrix

Located on the outside of the cell, made up of a network of proteins and carbohydrates. Functions include holding cells together, communication between cells, and identification of self