Kloroplasztok

Kloroplasztok are specialized organelles found in plant cells and eukaryotic algae that conduct photosynthesis. These oval-shaped structures contain chlorophyll, a pigment that absorbs light energy, primarily in the red and blue wavelengths, and reflects green light, giving plants their characteristic color. The process of photosynthesis within chloroplasts converts light energy, water, and carbon dioxide into glucose (a sugar) and oxygen. Glucose serves as the plant's food source, providing energy for growth and other metabolic processes, while oxygen is released as a byproduct. Chloroplasts have a double membrane envelope. Inside this envelope is a fluid-filled space called the stroma, which contains enzymes for the synthesis of carbohydrates. Within the stroma are stacks of flattened sacs called thylakoids, which are arranged in structures known as grana. The thylakoid membranes house chlorophyll and other pigments, as well as the protein complexes responsible for the light-dependent reactions of photosynthesis, where light energy is captured and converted into chemical energy in the form of ATP and NADPH. The ATP and NADPH are then used in the stroma to power the light-independent reactions (Calvin cycle), where carbon dioxide is fixed into organic molecules. Chloroplasts are semi-autonomous organelles, possessing their own circular DNA and ribosomes, allowing them to synthesize some of their own proteins.