Plant Cell Structure Flashcards
What are the main features which suits a palisade cell to its function of carrying out photosynthesis?
Long, thin cells that form a continuous layer to absorb sunlight.
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.
What is the chloroplast envelope?
A double plasma membrane that surrounds the organelle.
It is highly selective in what it allows to enter and leave the chloroplast.
What are grana in chloroplasts?
Stacks of disc like structures called thylakoids.
Within thylakoids is the photosynthetic pigment chlorophyll.
What is the stroma?
A fluid filled matrix where the second stage of photosynthesis takes place.
Within this is a number of other structures, such as starch grains.
How are chloroplasts adapted for their function?
Granal membranes provide a large surface area for attachment of chlorophyll, electron carriers and enzymes that carry out the first stage of photosynthesis.
The fluid of the stroma possesses all the enzymes needed to carry out the second stage of photosynthesis.
Chloroplasts contain both DNA and ribosomes so they can quickly and easily manufacture some of the proteins needed for photosynthesis.
Characteristic of all plant cells, the cell wall consists of microfibrils of the polysaccharide cellulose- what are its features?
The cellulose microfibrils have considerable strength.
They consist of a number of polysaccharides, such a cellulose.
There is a thin layer, called the middle lamella, which marks the boundary betwen adjacent cell walls and cements adjacent cells together.
What are the functions of the cellulose cell wall?
To provide mechanical strength in order to prevent the cell bursting under pressure created by osmotic entry of water.
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.
