Biology - Plants cell

Inside a plant cell

Let’s look inside a leaf to look closely at a plant cell.

First, we encounter the plant’s thick cell wall.

This is made from solid cellulose fibrils. It protects the plant cell and gives it shape.

Once inside the plant cell, we see a large vacuole at the center. This space is a store for water and dissolved substances that might be needed by the surrounding cytoplasm. The water pressure in the vacuole also pushes outwards against the cell wall, allowing the plant to support structures such as leaves and flowers.

plants make their food by photosynthesis, in chloroplasts.

Photosynthesis requires light energy from sunlight. Sunlight passing through the plant cell is absorbed by the chloroplasts. The sugars made this way are used by the plant for energy and to make other molecules.

If the function of the chloroplasts is to make sugars, then it is the function of the mitochondria to use the energy in the sugars to power the work of the cell. Respiration takes place in the mitochondria.

Many of the structures inside a plant cell are found in both plant cells and animal cells.




This is a cell from the plant leaf 

This is what the cell might look like if we cut away part of the cell wall and cell membrane to see what's inside.
These are the parts of a plant cell that are visible with a light microscope.


* Note that, without staining, all the parts of the cell would look transparent apart from the green chloroplasts.

     * When cutting through a tissue to make a microsope sile, you cut through many cells
     * When using a microscope what you see is in two dimensions.      


     *You need to interpret this to help you understand what a cell looks like in three dimensions.
  
    * Imagine that this cell was cut through as shown.  

* Draw a sketch to show how you think the 2D section  on the slide wsould look.

Remeber to label your sketch

This is what you would see,in the correct positions.
compare your sketch with this one

How is it the same? how is it different?



A drawing and a microscopic image of a leaf cell showing its parts 






Frequently Asked Questions 

What is a plant cell?

A plant cell is a eukaryotic cell that contains a true nucleus and certain organelles to perform specific functions. However, some of the organelles present in plant cells are different from other eukaryotic cells.

What are the different types of plant cells?

The different types of plant cells include- collenchyma, sclerenchyma, parenchyma, xylem and phloem.

Which organelles are found only in plant cells?

The organelles found only in plant cells include- chloroplast, cell wall, plastids, and a large central vacuole. The chloroplasts contain a green pigment chlorophyll that is responsible for the process of photosynthesis.

What is the composition of a plant cell wall?

The cell wall of a plant is made up of cellulose. Cellulose is a long, linear polymer of several glucose molecules.

Where does photosynthesis occur in plant cells?

Photosynthesis occurs inside the chloroplast of the plant cells. Chloroplast consists of a green pigment called chlorophyll. The light reactions occur within the thylakoids of the chloroplast where the chlorophyll pigment is found.



Shaik Urwa Noorin.

 









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