Now, let us continue with part three of the study of eukaryotes. Going back to our overview of eukaryotes, we will focus on the internal structures of the cell. The internal structures of the cell are organelles and they have been divided into membranous and non membranous organelles. This part three will focus on the membranous organelles, which are the endoplasmic reticulum, the Golgi apparatus, the lysosomes, the mitochondria and the paroxysms. let us study the endoplasmic reticulum first. The endoplasmic reticulum, also known as er includes the smooth and the rough endoplasmic reticulum.

The ER is a network of interconnected sacs known as systemness, that interconnect with the nuclear membrane, as seen over here. The smooth endoplasmic reticulum also known as SCR, is shown here in yellow. And it's also it is so called because it has no ribosomes on it and therefore it has a smooth surface. The smooth ER is responsible for the transport of lipids. The rough endoplasmic reticulum is shown here in light blue and it is so called because of the presence of ribosomes on its surface giving it its rough appearance. The rough ER is responsible for the transport of proteins.

The Golgi apparatus this apparently is a group of vesicles that has assistance and accounts face to it. The Golgi processes source and packages, lipids and proteins that come from the smooth ER and the rough ER so vesicles from both the smooth ER and Rafi are transport their contents to the sinc space through the incoming transport vesicles and after being processed, sorted and packaged within the Golgi, the outgoing transport vesicles are formed and exit through the trans face of the Golgi apparatus. Now, lysosomes lessons are circular types sacs that contain digestive enzymes, mainly acid hydrolysis, that help with digestion at the cellular level, that is they break down biomolecules such as nucleotides proteins, amino acids, and these come usually from waste products and cell debris. Now, mitochondria, the mitochondria is an organelle made up of many folds containing an internal membrane and an external membrane. The internal membrane has squeezes that are called Krista and an internal space that is called the matrix.

Mitochondria are responsible for transformation of chemical energy into cellular energy in eukaryotes, the last membranous organelle we will study the paroxysms. paroxysms are sticky carbohydrate structures. They are responsible for the breakdown of very long fatty acids through the process of beta oxidation. This is the first step in the breakdown of fatty acids. Here is a paroxysms shown in an electron micrograph. And in this picture of fluorescent microscopy, the green dots represent hundreds of paroxysms within the cell, which has this as its nucleus.

So these paroxysms correspond to these small green dots. So as a recap, the smooth endoplasmic reticulum transports lipids and the rough endoplasmic reticulum transports proteins within the cell. The Golgi apparatus processes sorts and packages these lipids and proteins from the ER. The lysosomes aid with digestion functions, and the mitochondria is responsible for cellular respiration. Finally, the paroxysms help with breakdown of fatty acids. This concludes the study of the membranous organelles of the eukaryotic cells.