Question

Mitochondria with lamellar cristae and rough endoplasmic reticulum.what is the relation between them?chemical changes that go on in mitochondria and rough endoplasmic reticulum and functions of both

Answer 1

Mitrochondria :-

It is also known as the power House of the cell.

Mitrochondria are the organelles or part of eukaryotic cell.

They are in the cytoplasm, not in the nucleus, They make most of the cell supply of ATP.

-Relationship b/w them,

Mitrochondria and ER (endoplasmic reticulam) are fundamental for the maintenance of cellular hemostasis and for detention of cell fate under stress condition.

Structural and functional studies revel the intracinter of these networks. These zones of close contact between ER and mitochondria called MAM (mitochondria associated membranes) support communication between the two organelles including bioenergetics and cell survival.

* MAM including key players in lipid metabolism, Ca2+ signaling elements (IP3R, VDAC), chaperones and peptidic tethers keeping mitochondria and ER in close contact.

Functions.

Mitrochondria and ER control Ca2+ singalis and Ca2+ depedende cellular process such as aptosis .

Prolong ER stress that  release of Ca2+ from the ER lumen at the MAM. such stress lead to increase Ca2+ uptake into the mitochondrial matrix. Elevated Ca2+ uptake induces an imbalance between mitochondrial Ca2+ load and the buffering capacity of the matrix and such imbalance ultimately leads to a prolonged episode of massive mitochondrial Ca2+ accumulation. Sustained Ca2+ accumulation triggers opening of the mitochondrial permeability transition pore (mtPTP),this results in swelling of the organelle & rupture of the OMM, and release of proapoptotic proteins into the cytosol.

ROS act as a local massengem b/w them.

Chemical changes in mitrochondria :-

ATP -> ADP+P+ Energy to function.

Break down of glocose.

In the cell cytoplasm , glucose is broken down to pyruvate .on the entery of mitrochondria pyruvate is converted to carbon dioxide and water .it's a chemical protein energy is transferred to ATP.

Overall reaction

C6H12O6 + 6O2 -> 6CO2+ 6H2O+ energy in the form of ATP.

Chemical changes of ER

Synthesis of organic molecules takes place and chemical reaction proceed rapidly.

Two form of ER are found

1 . smooth ER 2 . Rough ER

1.smooth ER

It is Rich in a large number of enjyme and most common in cell .

It involves in the synthesis of triglycerides , lipoprotein,complex and steoriod . It synthesis of phospholipids

Which are used in membrane formation and relases calcium

It involves in break down of glucose.

2. Rough ER

The ribosomes on the rough endoplasmic reticulum produce proteins that are secreted, such as digestive enzymes, hormones, contractile proteins and haemoglobins. Once these proteins are synthesised by the ribosomes they move through the channels of the endoplasmic reticulum where they are packaged into vesicles ready to be transported to the golgi apparatus along microtubules.