Download Life Processes

Life Processes
Life processes allow cells to respond to stimuli,
maintain homeostasis, reproduce, metabolize,
and adapt. Non-living things CANNOT carry out
these processes.
Nutrition
• The use of nutrients by an organism.
• Nutrients are obtained through food
except in the case of green plants. Where
do they obtain their nutrients?
Digestion
• The process that beaks large food molecules
into forms that can be used by the cell.
• Mechanical and chemical digestion break down
food for absorption.
• All foods we eat are eventually broken down into
the sugar glucose (C6H12O6) and carried to cells
by blood. Once in the cell glucose molecules are
broken down into H2O and CO2 in the presence
of oxygen and energy is released for our cells to
use. This happens in a cell’s mitochondria.
Absorption
• The ability of a cell to take in nutrients,
water, gases, and other substances from
its surroundings.
Transport
• The movement of nutrients, water, gases,
and other substances into and out of the
cell.
• Transport can be active (molecules carry
or “piggy back” other molecules into and
out of a cell; energy is required) or
passive (osmosis and diffusion; no energy
is required).
Respiration
• The release of energy from chemical
breakdown of compound within the cell.
• Oxygen must be present for respiration to
occur.
• O2 + C6H12O6  CO2 + H2O + NRG*
* energy
Secretion and Excretion
• Secretion…
• The release of
substances from a
cell.
• Excretion…
• The ability of the cell
to rid itself of waste
products.
Reproduction
• The process of fission in which one cell
divides to form two new identical new
cells.
• In regular body cells, this process is called
mitosis.
• In sex cells (sperm – male; egg – female),
this process is called meiosis.
Photosynthesis
• The cellular process in which a plant
makes food from water and carbon
dioxide, using energy from the sun.
Review
• For organisms to be considered living,
they must have cells, sensitivity to stimuli,
grow, maintain homeostasis, reproduce,
obtain/transform/use energy, and adapt.
• Living organisms carry out the life
processes of nutrition, digestion,
absorption, transport, secretion, excretion,
respiration, reproduction, and (in the case
of green plants) photosynthesis.