Question

Sphaerosomes are involved in
(a) Synthesis and storage of lipids
(b) Synthesis of protein
(c) β-oxidation of fatty acids
(d) Synthesis and storage of carbohydrate

Answer 1

Hint: Spherosomes are spherical or oval single membrane-bound structures present only in plant cells. They also supply hydrolytic enzymes to the vacuoles. They help in digesting their own cells when they get damaged.

Complete answer:
Sphaerosomes (spherosomes) are the cell organelles involved in the synthesis and storage of lipids in plants. They originated from the endoplasmic reticulum which then attaches with the fat molecule to develop a sphaerosome.

Additional Information
-They are the derivatives of vesicles of the endoplasmic reticulum having a ‘half unit membrane’.
-The membrane is 2 to 3.5 nanometres thick and is made up of a phospholipid layer with the polar heads lying towards the cytoplasm hydrophobic tails projecting inwards. The fluid present inside it is highly refractive.
-They mainly constitute lipids ($98\%$) and a very small amount of protein (1-$2\%$). The proteins present are mainly responsible for synthesizing the lipids.
-Because of the presence of lipids, sphaerosomes are mainly stained with Sudan dyes.
-They are mainly present in the endosperm of the seeds in their cotyledons in the form of fat globules or oil droplets.
-The β-oxidation of fatty acids in plants takes place in the mitochondria.
-The synthesis of carbohydrates in plants takes place in the chloroplast by the process of photosynthesis.
-The synthesis of protein in plants can take place in either of the three compartments, namely, cytoplasm, plastid, and mitochondria.

So, the correct answer is ‘Synthesis and storage of lipids'.

Note:
-The spherosome was first discovered by Perner in the year 1953.
-The membrane of spherosome consists of a protein known as Oleosin that stabilizes it. Hence, they are also known as Oleosomes.
-It consists of hydrolytic enzymes such as phosphatases, ribonucleases, proteases, etc. Therefore, they are also known as ‘plant lysosomes'.