Download Plant Cell Structure and Function

Plant Cell Structure and
Function
A plant cell is made up of many different organelles all
needed to be able to function properly.
Nucleus
The nucleus of the plant cell contains most of the DNA/genetic
information. It acts as the brain of the cell. It helps control reproduction,
movement and many other things. Only eukaryotic cells have a
nucleus.
Nucleolus
This is an organelle inside the nucleus. It is where ribosomal RNA is
produced.
Golgi Body
(also called the Golgi Apparatus or Golgi complex)
This is a flat, layered, sac-like organelle that looks like a stack of
pancakes and is located near the nucleus. The Golgi body puts proteins
and carbohydrates into membrane-bound vesicles to export from the
cell.
Ribosomes
This is where protein synthesis occurs. The proteins that are made can be
used as enzymes or to help other functions inside the cell. Ribosomes are
made up of approximately 60% RNA and 40% protein. They are very
small organelles and they are usually found floating around in the
cytoplasm or in the endoplasmic reticulum.
Without ribosomes, the plant cell would not work because of the lack of
proteins and amino acids.
Lysosomes
These are rarely found in plant cells. They contain digestive enzymes that break
down damaged or old cell parts, as well bacteria. Because of the acidic conditions
inside it, each lysosome is surrounded by its own membrane.
Rough Endoplasmic Reticulum (rough ER)
This is a big system of interconnected, membranous sack’s that is found in the cell’s
cytoplasm. Rough ER is covered with ribosomes that give it a rough look. Rough ER
transport materials through the cell and produces proteins in sacks called cisternae
(which are sent to the Golgi body, or to the cell membrane).
Smooth Endoplasmic Reticulum (smooth ER)
A big system of interconnected, membranous tubes that are found in the cell’s
cytoplasm. The space within the ER is called the ER lumen. Smooth ER moves
materials through the cell. It contains enzymes and produces and digests lipids (fats)
and membrane proteins; smooth ER buds off from rough ER, moving the newlymade proteins and lipids to the Golgi body and membranes.
Mitochondria
This is a spherical or rod-shaped organelle with a double membrane.
The inner membrane is folded many times, making a series of
projections (called cristae). The mitochondria change the energy stored
in glucose into ATP (adenosine triphosphate) for the cell.
Microtubules
These are like conveyer belts inside the cell. They move vesicles, granules
and organelles like mitochondria and chromosomes via special
attachment proteins.
They can work alone or together with other proteins to form more
complex structures (cilia, flagella or centrioles).
Cytoplasm
Cytoplasm is the liquid that fills cells. It has many different molecules
dissolved inside it. It contains enzymes, fatty acids and amino acids.
Plasma Membrane
The plasma membrane is found in all living cells. It is a thin layer of
protein and fat that surrounds the cell and is found inside the cell wall.
It is semi-permeable, letting some substances pass into the cell, but
making sure the organelles in it don’t escape. It is also like a barrier,
stopping unwanted substances getting through. The membrane is made
up of proteins and phospholipids. The proteins help move molecules
around the cell. If a cell didn’t have a plasma membrane, none of the
organelles would stay inside it, and therefore it would not be able to
function.
Plastids
Plastids are major organelles found in plant cells. They are responsible
for photosynthesis and store products like starch. They also help to
synthesise fatty acids as well as many other things. If a plant cell didn’t
have plastids, it would not be able to gain nutrition through
photosynthesis, and therefore it wouldn’t survive. This is why it is such an
essential organelle in a plant cell.
Vacuole
This is a sac containing water or storage products. Most living plant cells
have one or more large storage vacuoles that take up much of the
space in the cell, pushing the cytoplasm outwards. They also function in
waste disposal and growth.
Chloroplasts
They are long, disc-shaped organelles containing chlorophyll.
Photosynthesis (the process in which energy from sunlight is converted
into chemical energy – food) takes place in the chloroplasts.
Chloroplasts are quite large and contain layers of flat membranes
arranged as piles of discs.
Their green colour is due to the presence of chlorophyll.
Cell Wall
Outside the cell membrane of plant cells there is a cell wall made of
cellulose – a chemical similar in structure to fingernails! This material
gives plant cells their shape and firmness.
Amylosplast
An organelle in some plant cells that stores starch. Amyloplasts are
found in starchy plants like fruits.
Centrosome (microtubule organizing centre)
A small body located near the nucleus – it has a crowded centre
containing tubules. The centrosome is where microtubules are made.
During cell division (mitosis), the centrosome divides and the two parts
move to opposite sides of the dividing cell.
Here is a picture of various parts of a plant cell working together. All of
the organelles in a plant cell are needed for it to function properly. They
all have their own roles to keep the cell running, and without any of
them, the cell would simply not work.
Chantelle 12DIN