Transcript cellular processes

Cellular Processes
Standard 7-2.4
Explain how cellular processes (respiration, photosynthesis, waste
elimation, mitosis, and reporduction) are essential to the survival of an
organism.
Diffusion
 One way materials move across the cellular membrane
 Materials move from area of higher concentration to
area of lower concentration
WHAT DOES THAT MEAN?
•Molecules like their own space.
•If there are too many in one space then molecules
will move to a place with less stuff (less
molecules).
DOES NOT
NEED ENERGY
TO MOVE!
HIGH
CONCENTRATION
Molecules move in and out of the cell
through the cell membrane
Osmosis
 diffusion of water across the cellular membrane
What are the consequences to
a cell if too much water goes…?
 INTO THE CELL
 OUT OF THE CELL
SHRINKS
BLOATS
ACTIVE TRANSPORT
NEEDS ENERGY to “move”
substances across the
membrane
•USUALLY MOVES SUBSTANCES FROM A LOW CONCENTRATION
TO A HIGH CONCENTRATION
Active transport requires
cell energy.
Diffusion does not.
Active transport:
Endocytosis:
 Cell membrane surrounds a substance and engulfs it
Exocytosis:
 Vesicle with waste fuses with a cell membrane and then
releases waste outside of cell(reversal of endocytosis)
PHOTOSYNTHESIS
 Plants use light energy (sunlight) to combine
carbon dioxide and water to make simple
sugars (glucose)
 Once the sugars are formed, they are either
used by the plant or stored in the vacuoles.
 Photosynthesis occurs in the chloroplasts.
 Plant cells also release oxygen gas.
RESPIRATION
 Cells break down simple sugars into carbon
dioxide and water and release energy.
 cell uses the energy to build, repair, and
reproduce cells.
 Respiration occurs in the mitochondria of
cells.
WASTE ELIMINATION
 Organisms rid the cells of waste products that could be
harmful to the cell.
 As waste particles accumulate in a cell, the waste will
move out of the cell and be eliminated.
Metabolism
The total of ALL chemical reactions
in an organism
Enzymes
Molecules that act as catalysts for
cell processes (chemical reactions)
MITOSIS




cell reproduction; process of cell division,
occurs in the nucleus of the cell
enables a cell to make an exact copy of it
needed for growth, replacement, and asexual
reproduction
Results:
 production of two daughter cells from a single
parent cell.
 daughter cells are identical to one another and to
the original parent cell