Flashcards in lecture 1.3 Deck (54):
How do Prokaryotes differ from Eukaryotes?
most lack internal membrane systems
What are the different shapes?
cooci, bacilli, vibrios, spirilla, spirochetes
How is the arrangment determined?
determined by plane of division
determined by separation or not
pairs of spheres
chains of spheres
grape like clusters
4 cocci in a square
cubic configuration of 8 cocci
very short rods
resemble rods, comma shaped
network of long, multinucleate filaments
organisms that are variable in shape
How small can a bacteria be?
0.3 μm (Mycoplasma)
How large is the average rod?
average rod – 1.1 - 1.5 x 2 – 6 μm (E. coli)
How large can bacteria be?
– 600 x 80 μm (Epulopiscium fishelsoni)
Why is size/shape important?
important for nutrient uptake
surface to volume ratio (S/V)
What typically happens to cells when they are under stress?
When cells are under stress, they typically get rounder and smaller
What is an advantage to being small besides S/V ratio
small size may be protective mechanism from predation
What are the common features of Bacterial Cell Orginization? (in regards to layers)
Cell envelope – 3 layers
What does the Bacterial Cell Evelope contain?
Layers outside the cell wall
What are some plasma membrane functions?
Encompasses the cytoplasm
Selectively permeable barrier
Interacts with external environment
How does the plasma membrane interact with the external barrier?
receptors for detection of and response to chemicals in surroundings
amphipathic lipid has what two parts?
polar ends (hydrophilic – interact with water)
non-polar tails (hydrophobic – insoluble in water)
Peripheral in regards to the plasma membrane=
loosely connected to membrane
Integral in regards to the plamsa membrane=
amphipathic – embedded within membrane
carry out important functions
may exist as microdomains
bacterial membranes do not contain sterols, but contain what?
hopanoids, sterol like molecules
What are the macronutrients?
C O H N S P K Ca Mg and Fe
Where can you find C O H N S P?
organic molcules such as proteins, lipids, carbohydrates, and nucleic acids
What do you use K Ca Mg and Fe for?
cations used in enzymes and biosynthesis
What are the micronutrients?
Mn Zn Co Mo Ni and Cu
Where are micronutrients found?
Ofrten in the water or media components
What do micronutirents serve for?
Serve as enzymes and cofactors
What are the growth factors?
essential cell components (or their precursors) that the cell cannot synthesize
must be supplied by environment if cell is to survive and reproduce
What are the classes of growth factors?
purines and pyrimidines
What are amino acids used for (growth factor)
What are purines and pyrimidines used for? (growth factor)
nucleic acid synthesis
What are vitamins used for? (growth factor)
What is passive diffusion
Molecules move from region of higher concentration to one of lower concentration between the cell’s interior and the exterior
What molecules travel by passive diffusion
H2O, O2, CO2, glycerol, ethanol
What is facilitated diffusion
movement of molecules is not energy dependent
direction of movement is from high concentration to low concentration
size of concentration gradient impacts rate of uptake
How is facilited diffusion different from passive diffusion?
uses membrane bound carrier molecules (permeases)
smaller concentration gradient is required for significant uptake of molecules
effectively transports glycerol, sugars, and amino acids
more prominent in eukaryotic cells than in bacteria or archaea
What defines active transport?
move molecules against the gradient
concentrates molecules inside cell
involves carrier proteins (permeases)
--carrier saturation effect is observed at high solute concentrations
What defines an ABC Transporter?
- 2 hydrophobic membrane spanning domains
- 2 cytoplasmic associated ATP-binding domains
- Substrate binding domains
What is the energy for active transport?
--ATP or proton motive force used
What are the types of Secondary Active Transport?
symport – two substances both move in the same direction
antiport – two substances move in opposite directions
two substances both move in the same direction
two substances move in opposite directions
How does secondary active transport get its energy?
Use ion gradients to cotransport substances
What is group translocation?
Energy dependent transport that chemically modifies molecule as it is brought into cell