Cells are the smallest unit of life that can function independently
Being composed of cells is one of the most basic characteristics of life
All organisms are made of one or more cells
The cell is the fundamental unit of life
All cells come from preexisting cells
All cells have the same basic chemical composition
All cells use energy
All cells contain DNA that is duplicated and passed on as each cell divides
Light microscopes are used to view the entire cell
Electron microscopes are used to view the parts of cells, and viruses, which are smaller and require highermagnification
A transmission electron microscope (TEM) is a very powerful tool for seeing internal cell structures
A scanningelectronmicroscope (SEM) is also very powerful and reveals details on cell surfaces
All cells have genetic material, ribosomes, cytoplasm, and a cell membrane
Prokaryotes are small, simple in structure, and lack a nucleus
Bacteria and archaea are two different domains of prokaryotes
Eukaryotes are larger and more complex, with many internal parts including a nucleus and other membranous organelles
Protists, fungi, plants, and animals are eukaryotic
Some features are common to all three domains (cellmembrane), while others are unique to each domain
Bacteria lack membrane-bounded organelles, with ribosomes and DNA free in the cytoplasm
Plant cells have most of the same membrane-bounded organelles as animal cells, with additional structures like a large central vacuole, cell wall, and chloroplasts
Cell membranes form a barrier between the cell and the outside world, regulating passage of substances and maintaining homeostasis
Cell membranes are composed of phospholipids, which are amphipathic molecules with polar and nonpolar regions
Phospholipids are made of a molecule of glycerol, a phosphate group, and 2 fatty acids
Phospholipids spontaneously form bilayers in water, creating a selectively permeable membrane to lipids and small, nonpolar molecules
Phospholipids make up the cell membrane
The nucleus controls protein production
Proteins are synthesized on ribosomes
Lysosomes contain digestiveenzymes
The cytoskeleton has three major components: Actin molecules microfilaments, intermediate filaments, and microtubules
Plant cells are surrounded by a cell wall
Plant cells communicate through plasmodesmata
Different membrane proteins carry out different functions
Cell membranes are fluid mosaics
The membrane is neither a solid nor a liquid; it is more like Jell-O
The combination of phospholipids and proteins forms a fluid mosaic
The nucleus controls protein production
The nucleus contains DNA, which specifies the “recipe” for the proteins
The nucleus also contains the nucleolus, which synthesizes ribosomes
RNA moves from the nucleus out to a ribosome, where the protein is synthesized