MOVEMENT & LIFE
CYTOPLASMIC STREAMING: MOVEMENTS AT CELLULAR LEVEL
–Visible movements are indicative of life
–Visible Movements can be:
üGrowth related
üNon growth related
–Some movements invisible to naked eye:
vVery small scale / molecular level movements
Molecular movements are defining criteria of life
Required for
repair & maintenance of organized structure
*Virus: show
molecular structure only when in host cell
LIFE PROCESSES: Maintenance Processes in living organisms
–Processes essential for life
–Performed even when body seems to be doing nothing
–Require energy
They include:
qNutrition: to obtain food from outside. Food is source
of energy. Common element in food C
qRespiration: For breakdown & burning of food, to
obtain energy in a common form ATP. Requires O2. Involves
oxidizing reducing reactions.
qTransportation: to carry food & O2 to all parts
of body
qExcretion: removal of by products / waste
Unicellular vs Multicellular:
vIn
unicellular organisms Diffusion is sufficient to provide for exchange.
vIn
multicellular diffusion not so because:
1.Large
size, more needs
2.Not
all cells are exposed to outer environment
