Ch3, 3.1-3.2 Flashcards
Cytology
The study of cells
Spontaneous generation
Living things arise from nonliving things; meat experiment with maggots to refute
Three components of cell theory
- Cells derive from other cells
- Every living organism is composed of cells
- Cells are the simplest structural and functional unit of life
Squamous
Squashed
Cuboidal
Cubes, in a circle
Columnar cells
Columns
Polygonal cells
4+ sides
Stellate cells
Stars
Spheroidal cells
Spheres
Discoidal cells
Discs (Red blood cells)
Fusiform cells
Spindle-shaped; eyeballs
Fibrous cells
Fibers
Surface area to volume ratio
When are given increase in diameter, volume increases more than surface area
Volume of a cell
V≈D^3
Volume is proportional to diameter cubed
Surface area of a cell
SA≈D^2
Surface area is proportional to diameter Squared
Plasma membrane Of a cell is the:
Barrier between inside and outside of cell
Cytoplasm
What’s inside the cell
Extracellular fluid or interstitial fluid
What’s outside of cell
Basal surface of plasma membrane
What is attached to bottom of cell or basement membrane
Apical surface plasma membrane
Part exposed to extracellular fluid or top of cell
Lateral surface of plasma membrane
Sides of the cell
3 Functions of the plasma membrane
- Cell boundaries
- Interacts with other cells/outside environment
- Controls passage of materials in/out of cell “gatekeeper” (Semi permeable)
What faces/spaces does the phospholipid bilayer have?
– intracellular face
– extracellular face
– intercellular space
Phospholipid bilayer components of plasma membrane
- Phospholipids (75%) 
- Cholesterol (20%)
- Glycolipids (5%)

Phospholipid by layer of plasma membrane is amphipathic because:
amphipathic:
-Fatty acid tails – Hydrophobic(away from Intracellular fluid and interstitial fluid with intercellular space between),
-phosphate head - hydrophilic
Fluid Mosaic Model
Cell membrane moves in Waves; Flexibility
Lipid rafts
Lipid particles float along membrane
In the phospholipid bilayer of the plasma membrane, cholesterol does what?
Stiffen membrane; provide structure
In the phospholipid bilayer of the plasma membrane, glycolipids look like what and do what?
Little tags; contribute to glycocalyx: help maintain integrity of cell
Limitations on cells:
Limit on cell size
Surface area to volume ratio
What size are most cells?
Most are 10 to 15 µm in size
Which cells can you see with the naked eye?
Nerve cells and muscle cells
Why do cells try to stay balanced in size?
So they can support themselves:
– Nutrients from SA.
If the diameter gets too large, SA isn’t big enough to take in enough nutrients for metabolism to balance out with the cell volume.
get nutrients from the surface of the cell so if volume keeps increasing at a greater rate, surface area isn’t going to keep up. If diameter gets too large, cell is not able to support itself
Fluid mosaic model
Membrane is not stagnant, but moves in waves; flexibility
What are microvilli?
Extensions of the plasma membrane that increase cells surface area; for absorption or sensory functions
Brush border
Microvilli Fringe at apical cell surface
Cilia
Long Hair-like extensions of the plasma membrane.
Two kinds of cilia
- Non-motile primary ciliam 
- Motile cilia
Function of nonmotile primary cilia
Sensory function; monitors flow of fluid
Function of motile Cilia
Propels mucus, egg cell, cerebrospinal fluid with power stroke and recovery stroke
Flagellum
Longer than cilia, Beats in undulating fashion; ex:sperm tail
Pseudopods
Cytoplasm – filled extensions of the cell that change continuously
