Module 1- Cells, cell size, diffusion Flashcards
Metazoa
Multicellular Animals:
- Heterotrophs
- Body is organized around a digestive cavity
- no cell walls
- Motile (have the ability to move)
Embryophyta
Seed bearing plants
- Photosynthetic
- Cell wall
- Meristem (plant growth cells)
Multiple cells adhere and recognize to others via cell-to-cell junctions
Multicellular Organism
Communication/signaling between cells can occur via cell-cell connection
Multicellular Organism
Cellular differentiation and specialization
Multicellular Organism
multiple cells aggregate together but no cell-cell connection
Colonial Unicellular
Communication/signaling occurs only external to cells - little coordination
Colonial Unicellular
Cells nearly identical
Colonial Unicellular
Serial division without separation
Clonal Development
Cells come together, adhere
Aggregation
Connections between the cytoplasm of one plant cell to the cytoplasm of an adjacent plant cell
Plasmodesmata
Fluid that passes through the plasmodesmata
Symplast
organelles with common origins to chloroplasts
Plastids
Connections between animal cells
Gap Junctions
Very close adherence between two animal cells
tight junctions
Attaches plant cells to one another
Middle lamella
ties the fibers of the cell wall together
Pectins
Prokaryotes
- no membrane bound organelles
- no nucleus
- small in size
Eukaryotes
- Nucleus
- Membrane bound organelles
- large in size
Advantages to larger size
- ability to survive
- greater complexity
- store energy
Disadvantages to larger size
- Diffusion limitations
- difficult to communicate
Reynolds number
Value less than 10: flow is orderly and reversible, slow movement
Value larger than 100: flow is disorderly, fast movement
Diffusion limits
- Distance
- number of places it can occur
- Amount of things
- speed of travel
Fick’s law
Q = D * A (∆M/X)
Q= Rate of diffusion
D= Diffusion Coefficient
A= Area
∆M= difference in the amount of stuff
X= distance to travel between two points
t = X^2
the time it takes a particle to diffuse is equal to the square of the distance it must travel
V = L^3
Volume equates to the length cubed
A = L^2
Area equates to the length squared
Solutions to Size
- Decrease metabolic processes limited by diffusion
- Change shape to increase surface area
- Divide the organism into smaller cells to increase SA
- Bulk flow systems
Prokaryotes -> Eukaryotes
membrane needed more SA so it folded in on itself
Isometry
- Growth of structure is proportional to growth of body
- Same shaped structures, different sizes (baby to adult)
Allometry
- Growth of structure isn’t proportional to growth of body
- Different shaped structures, different sizes (baby to adult)
Growth Slope is larger than predicted slope
positive allometry
Growth slope is smaller than predicted slope
negative allometry
growth slope is the same as predicted slope
isometry
scaling relationships
y/x relationship = Predicted
Hyperplasia
increase in cell number
Hypertrophy
increase in cell size without an increase in number
Endotherms
Can regulate metabolic heat production
