Slides in this set
Leaf palisade cell
The leaf palisade cell is a typical plant cell. Its
function is to carry out photosynthesis. The main
features that help the cell carry out its
Long, thin cells that form a continuous layer to
Numerous chloroplasts that arrange
themselves in the best positions to collect the
maximum amount of light,
A large vacuole that pushes the cytoplasm and
chloroplasts to the edge of the cell.
Chloroplasts are the organelles that carry out
Chloroplasts vary in shape and size but are typically
disc-shaped 2-10um and 1um in diameter. The
following are there main features:
The chloroplast envelope is a double plasma membrane
that surrounds the organelle. It is highly selective in
what it allows to enter and leave the chloroplast.
The grana are stacks of up to 100 disc like stuctures
called thylakoids. Within the thylakoids is the
photosynthetic pigment called chlorophyll. Some
thylakoids have tubular extensions that join up with
thylakoids in adjacent grana. The grana are where the
first stage of photosynthesis takes place.
The stroma is a fluid-filled matrix where the second
stage of photosynthesis takes place. Within the stroma
are a number of other structures, such as starch grains.…read more
Chloroplasts are adapted to their function of
harvesting sunlight and carrying out
photosynthesis in the following ways:
The granal membranes provide a large surface area
for the attachment of chlorophyll, electron
carriers and enzymes that carry out the first stage
of photosynthesis. These chemicals are attached to
the membrane in a highly ordered fashion.
The fluid of the stroma possesses all the enzymes
needed to carry out the second stage of
Chloroplasts contain both DNA and ribosomes so
they can quickly and easily manufacture some of
the proteins needed for photosynthesis.…read more
Characteristics of all plant cells, the cell wall consists of
microfibrils of the polysaccharide cellulose, embedded in a
matrix. Cellulose microfibrils have considerable stregth and
so contribute to the overall strength of the cell wall. Cell
walls have the following features:
They consist of a number of polysaccharides, such as
There is a thin layer, called the middle lamella, which marks
the boundary between adjacent cell walls and the cements
adjacent cells together.
The functions of the cellulose wall are:
To provide mechanical strength in order to prevent the cell
bursting under the pressure created by the osmotic entry of
To give mechanical strength to the plant as a whole.
To allow water to pass along it and so contribute to the
movement of water through the plant.…read more
Differences between plant and
Plant cells Animal cells
Cellulose cell wall surrounds the cell as Only a cell surface membrane surrounds
well as a cell surface membrane. the cell.
Chloroplasts are present in large numbers Chloroplasts are never present.
is most cells.
Normally have a large, single, central If vacuoles are present they are small and
vacuole filled with cell sap. scattered throughout the cell.
Starch grains are used for storage. Glycogen granules are used for storage.…read more