BIOL 1081 Lecture Notes - Lecture 5: Cell Membrane, Nucleoid, Tubulin
Ch. 4 Learning Outcomes
Tuesday, September 5th
Cells & Prokaryotes vs. Eukaryotes Reading: Sections 4.1-4.3 in textbook
1. Describe the factors that limit cell size.
• Surface area available for diffusion
o As size increases, length of time for diffusion from outside membrane to interior
of cell increases
• Temperature
• Concentration gradient of diffusing substance
• Distance over which diffusion must occur
• Cell theory-
o All organisms are composed of one or more cells, and the life process of
metabolism and heredity occur within these cells
o Cells are the smallest living things, the basic units of organization of all organsims
o Cells arise only by division of a previously existing cell
2. List the structures that all cells have, describing the composition and function of each of these
structures.
• Nucleoid (P) or nucleus (E)
o Genetic material is located; located in center, generally DNA
• Cytoplasm
o Semifluid matrix that fills the interior
o Contains sugars, AA, and proteins
o Contains organelles
o Cytosol- fluid portion of cytoplasm that contains organic molecules and ions, in
between plasma membrane
• Ribosomes- synthesize proteins
• Plasma membrane
o Encloses a cell and separates its content from its surroundings
o Phospholipid bilayer about 5-10 nm
o Transport proteins, markers, receptor proteins
3. List the basic cellular characteristics that distinguish between prokaryotic and eukaryotic cells.
• Prokaryotic
o Small, consist of cytoplasm surrounded by a plasma membrane and encased in a
cell wall (peptidoglycan)
o No distinct interior compartments
o Lack membrane bound organelles
o Cytoskeleton- actin and tubulin
o Some flagella
o Nucleoid
o Circular DNA
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