Thylakoids are sacs found inside chloroplasts.
Thylakoid is not a term that is part of the dictionary of the Royal Spanish Academy ( RAE ). The concept is used to name the sacs that, in plants, are found inside the chloroplasts .
It should be noted that chloroplasts are found in organisms that carry out photosynthesis . These are membrane-enclosed organelles that house the thylakoids. In these bags are the molecules that allow chemical energy to be obtained from light energy .
Characteristics of chloroplasts
Of the chloroplasts, for their part, it is also worth highlighting other significant signs of identity such as the following:
- They have very different shapes and sizes, although certain species tend to have very similar ones, as occurs, for example, in algae.
- The number of chloroplasts is also very varied.
- One of the fundamental parts they have is the stroma , which is where a notable concentration of enzymes is housed. Among these enzymes are those responsible for the reduction and assimilation of sulfates and nitrates, those that participate in the replication and translation of chloroplast DNA, and those that are most responsible for the photosynthetic reduction process of carbon dioxide.
- In the same way, in the stroma there are also lipid droplets and starch grains, which accumulate after the aforementioned process of photosynthesis takes place.
- Thylakoids are found in this stroma. On the other hand, around the thylakoids there is a membrane that marks the lumen space.
The thylakoids are responsible for absorbing photons.
Thylakoid function
The function of the thylakoids is the absorption of photons found in the sun 's rays. In this way, the photochemical phase takes place in the bags (which are stacked in formations known as grains ).
Chlorophyll , xanthophylls and carotenoids are some of the pigments with photosynthetic capacity found inside the thylakoids. The structure also houses enzymes , lipids and proteins that are necessary for the development of the process.
Other information of interest
In addition to everything stated above, it is worth knowing other interesting facts about thylakoids:
- They are stacked like coins or batteries.
- Within the thylakoids there are two clearly differentiated groups in terms of pigment systems: the PSII (Photosystem II) and the PSI (Photosystem I), which is where the P700 antenna molecule is located, which is identified because it absorbs the greatest amount of light possible.
- In the case of PSII there is a really important molecule such as P680, which is normally bleached, oxidized or photonized.
It should be noted that chloroplasts with thylakoids are part of the palisade parenchyma , a type of tissue found in leaves. Its cells , which are located under the upper layer of the epidermis , are elongated and allow photosynthesis to be carried out, which is essential for plants to obtain the energy they need for their survival.