Transcript Comparative Study of Plant and Animal Cells

What differentiates a plant cell
from an animal cell?
12D The student is expected to differentiate between structure and function
in plant and animal cell organelles, including cell membrane, cell wall,
nucleus, cytoplasm, mitochondrion, chloroplast, and vacuole;
12E The student is expected to compare the functions of a cell to the
functions of organisms such as waste removal;
Review: Common Cell Structures and Functions
Structure
Cell membrane
Function
Cytoplasm
Jelly-like substance inside the cell but outside of
the nucleus that dissolves sugars, salts, and
chemicals and where important chemical reactions
take place
Nucleus
Mitochondria
Contains the DNA
Barrier that separates the cell’s contents from the
outside
Selects what materials go in or out of the cell
Converts sugars into usable energy molecules so
cells can do work in a process called cellular
respiration
How plant cells are enclosed
Cell membrane Cell wall
• Plant cells have cell
membranes, but they are
very thin and crushed
against the cell wall unlike
an animal cell membrane
which is substantial.
– It is common for plant
cells to be talked about
as just having a cell wall.
Cell wall
• Cell walls select what materials go in and out
of cells.
• Cell walls are strong.
– prevent a plant cell from exploding when in
contact with pure or almost pure water
– act as skeletal system for plant cells
Vacuoles store water in plant cells.
• Plant cells have large vacuoles with an
important function for the plant cell.
– Only some animal cells have vacuoles, and they
are small with minor function.
• The vacuole fills with so much water that it
swells up and pushes against the cell
membrane.
• Because a cell wall is present too, the plant
cell doesn’t explode.
The pressure the vacuole exerts on the cell
wall is called turgor pressure.
• If you water a plant cell with salt water, it will shrink the cell and cause the
plant cell to die.
• If a plant does not have enough water, it will become droopy.
• If a plant cell has plenty of fresh water, turgor pressure will result, and
the plant will hold itself up.
TURGOR PRESSURE
Turgor pressure is one way plants respond to an environment with plenty of water.
How plants obtain energy
• Plants do not “eat” food for energy.
• Plants must make their own food and convert that
to energy or store it for later use.
• Chloroplast: organelle that captures radiant energy
from sunlight and converts that to sugar molecules
Making, using, storing energy
• Plants make energy molecules (sugar) through
the process of photosynthesis.
• Plants use sugar molecules to create energy
needed to carry on its functions through the
process of cellular respiration.
• Plants store unused sugar molecules in the
form of starch.
– Examples: potato, carrot root, garlic bulbs