Chloroplast

• A specialized membrane-bound cytoplasmic organelle that is the principal site of photosynthesis in eukaryotic cells.

• Organelles of photosynthesis in plants and algae.

• Each chloroplast contains folded membranes that provide tremendous surface area for the reactions of photosynthesis.

Chloroplast

• A type of plastid: organelle specialized for producing food by means of photosynthesis and for storage.

• Chloroplasts are organelles that have amazing ability to make food in the form of starches and sugars using air, water, and the energy from sunlight, a process called photosynthesis.

• In land plants, it also serve as temporary storage sites for starch grains.

• Two membranes contain and protect the inner parts of the chloroplast. The stroma, a gelatinous matrix containing ribosomes, DNA, enzymes.

• Suspended in the stroma are between 10 and 100 grana(singular: granum), each composed of a stack of 10-20 disk shaped thylakoids.

One thylakoid stack is called a granum.

• Thylakoids, each consists of a membrane studded with photosynthetic pigments and enclosing a volume called thylakoid space.

• The stacks of sacs are connected by stromal lamellae. The lamellae act like the skeleton of the chloroplast, keeping all of the sacs a safe distance from each other and maximizing the efficiency of the organelle. 

www.biology-online.org/chloroplast

References

• Karp,Gerald.Cell Biology(6th Edition) • Hoefnagels, Morielle. Biology:Concepts & Investigations• Biggs,Alton L. Emmeluth Ed. D.,Donalds. Gentry, Chris L. MERILL

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