Ultrastructure of Mitochondria

Ultrastructure of Mitochondria:

In 1953, Palade and Sjostrand independently described the ultrastructure of mitochondria. Mitochondria are bounded by an envelope consisting of two concentric membranes, the outer and inner membranes. The space between the two membranes is called inter-membrane space.

A number of invaginations occur in the inner membrane; they are called cristae . The space on the interior of the inner membrane is called matrix.

Outer Membrane:

The outer mitochondrial membrane has high permeability to molecules such as sugars, salts, coenzymes and nucleotides etc. It has many similarities with the ER but differs from it in some respects, e.g., mono-amine-oxidase is present in the mitochondrial outer membrane but not in ER.

 The mitochondrial outer membrane contains a number of enzymes and proteins.

Inter-Membrane Space:

The inter-membrane space is divided into two regions:

(1) Peripheral space and

(2) Intracristal space.

Large flattened cristae are connected to the inner membrane by small tubes called peduculi cristae. The inter-membrane space has several enzymes of which “adenylate kinase” is the chief one. This enzyme transfers one phosphate group from ATP to AMP to produce two molecules of ADP.

Inner Membrane:

The inner mitochondrial membrane invaginates inside the matrix; the invaginations are called cristae. This membrane has a high ratio of protein to lipid. The inner membrane contains large number of proteins which are involved in electron transfer (respiratory chain) and oxidative phosphorylation. The respiratory chain is located within the inner membrane, and consists of pyridine nucleotides, within the inner membrane, and consists of pyridine nucleotides, flavoproteins, cytochromes, iron-sulphur proteins and quinones.

Matrix:

The interior of mitochondrion is called matrix. It has granular appearance in electron micrographs. Some large granules ranging from 30 nm to several hundred nanometers in diameter are also present in the matrix. The matrix contains enzymes and factors for Krebs cycle, pyruvate dehydrogenase and the enzymes involved in β-oxidation of fatty acids.

Which came first, Chicken or Egg???

Hey guys,
we have been very close with a question since childhood ,
      and we were all anxious to find out the answer of the question "Which came first , Chicken or Egg? 

Which came first, the chicken or the egg? The chicken, no, the egg, no, the chicken, no, the egg. It's enough to make your head spin right off your neck.

     Basically, many, many moons ago there was a chicken-like bird. It was genetically close to a chicken but wasn't a full-blown chicken yet. we can call it proto-hen.
      So proto-hen laid an egg, and proto-rooster fertilized it. But when the genes from ma and pa almost-chicken fused, they combined in a new way, creating a mutation that accidentally made the baby different from its parents. Although it would take millennia for the difference to be noticed, that egg was different enough to become the official progenitor of a new species, now known as the chicken! So in a nutshell or an eggshell, two birds that weren't really chickens created a chicken egg.

If we need a simple description then here it is-:

Because Ovocleidin-17 protein  is expressed by the hen and not the egg , the bird in which the protein first arose, though having hatched from a non-reinforced egg, would then have laid the first egg having such a reinforced shell: the chicken would have preceded this first 'modern' chicken egg.

          and hence, we have an answer: The egg came first, and then it hatched a chicken.
      

The life expectancy of the father increases with the birth of the daughter

Hey dear friends,

       A huge number of scientists show for the first time that number of daughters was positively related to a longer life span of their fathers, increasing their longevity on average by 74 weeks per daughter born, while number of sons did not have a significant effect on paternal longevity.

                 The sleepless nights and stress that often accompany parenthood may not sound like the ingredients for a longer life, but according to a new study, having daughter could add years to a parent's lifespan.
    
      energetic and nutritional demands of pregnancy and breastfeeding render reproductive costs much higher in women than in men, women with a large number of children should show signs of deterioration in condition, while men with large families should not. However, whether reproductive costs reduce longevity in women is still questionable, and in men this issue has not been adequately addressed. In addition, since sons are energetically more expensive to produce than daughters, having sons should have a more pronounced negative impact on maternal longevity than having daughters. 

     In contrast, in women, the number of daughters and number of sons reduced maternal longevity and did so to the same extent, on average by 95 weeks per son or daughter, indicating that for women, the costs of having sons and daughters are similar.

A cockroach can live for a week without its head.

Can you live without your head?

   
      You can't but a cockroach can live without his head for a week.

A cockroach can live for a week without its head. Due to their open circulatory system, and the fact that they breathe through little holes in each of their body segments, they are not dependent on the mouth or head to breathe. The roach only dies because without a mouth, it can't drink water and dies of thirst.

 How?

After you cut their heads off, very often their necks would seal off just by clotting.
             
            The hardy vermin breathe through spiracles, or little holes in each body segment. Plus, the roach brain does not control this breathing and blood does not carry oxygen throughout the body. Rather, the spiracles pipe air directly to tissues through a set of tubes called tracheae.

Baby sharks shed teeth in the womb:

A SHARK sheds teeth throughout its life, continually replacing them with new
ones. Researchers have now found that this tooth replacement starts before
birth.

       Two researchers named 
Michael Gottfried , Malcolm Francis studied a pregnant female great white shark,
Carcharadon carcharias, that had been caught by fishermen.

Teeth are vital to marine predators, and that  whites has evolved a
particularly dangerous set. To keep its dental arsenal in peak condition, the
great white doesn't wait for teeth to wear. 

                But the researchers were surprised to find that, many baby shark's teeth began to grow while they are in the mothers womb.Many of these teeth were tiny, conical and unserrated, very

different from those of adult great whites.

Sharks’ teeth have

different shapes, depending on where they are in the jaw. 

Last but not the least , they fight among themselves and  whoever can survive in this fight will  born.

Doe's Pigeon Give Milk??? Come lets talk about this a bit.

Hey, have you ever thought that a Pigeon can give milk??🕊️

    Yes , this is absolutely true.
 
The pigeon is one of only three bird species (the others being flamingos and male emperor penguins) known to produce 'milk' to feed their young. In pigeons the milk starts to be produced in the crop of the parent birds two days before eggs hatch. ... Squabs are fed the 'milk' until they are around 10 days old.

Deakin University scientists have revealed some of the secrets behind the pigeon’s rare ability to produce ‘milk’ to feed its young.

Deakin PhD student Meagan Gillespie and research fellow Dr Tamsyn Crowley, along with colleagues from the University’s Institute for Technology Research and Innovation and CSIRO Livestock Industries, have studied the genes behind pigeon ‘milk’ production. They found that, like mammalian milk, it contains antioxidants and immune-enhancing proteins important for the growth and development of the young.

“Producing milk to feed babies is normally the domain of mammals, including humans. However, the pigeon is one of only three bird species (the others being flamingos and male emperor penguins) to produce a milk-like substance to feed their young,” Dr Crowley explained.

“We looked at the genes involved in the production of pigeon ‘milk’ and found that it contains antioxidants and immune-enhancing factors. This suggests that, like mammalian milk, it plays a key role in enhancing the immune system of the developing baby.”

Both female and male pigeons produce a nutrient rich substance in their crop to feed their young (squabs). This substance has been likened to lactation in mammals and is referred to as pigeon ‘milk’. This ‘milk’ is essential for the growth and development of the pigeon squab, and without it they fail to thrive.

“Bird crops are normally used to store food. However, in the pigeon the crop changes prior to ‘lactation’ in response to hormones and returns to its ‘non-lactating’ state at the end of the lactation period, a bit like the mammary gland,” Ms Gillespie explained.

“During ‘lactation’, a curd-like substance is created from fat-filled cells that line the crop and regurgitated to feed the squab. This ‘milk’ contains protein, fats, minerals and antibodies to provide nutrition to the young.”

While studies have investigated the nutritional value of pigeon ‘milk’, very little is known about what it is or how it is produced.

“This study has provided an insight into the process of pigeon ‘milk’ production by studying the genes expressed in the ‘lactating’ crop,” Ms Gillespie said.

“Birds are different to other animals in that they don’t have sweat glands, but they do have the ability to accumulate fat in their outer skin cells (keratinocytes) which act like sweat glands. We found that the evolution of pigeon ‘milk’ appears to have developed from the ability of these outer skin cells to accumulate fat.

“The way pigeon ‘milk’ is produced is an interesting example of the evolution of a system with similarities to mammalian lactation, with pigeon ‘milk’ fulfilling a similar function to mammalian milk but produced in a different way.”

The results of the study will be published this week in BioMed Central’s journal BMC Genomics.

Do Male Pigeons Produce Milk?

   Although milk is exclusively a mammalian production, some birds, such as pigeons, penguins and flamingos, produce a milk-like substance which provides similar benefits to their young. Both female and the male pigeons produce it in their crop, and like mammalian milk production is controlled by the hormone prolactin.

Is Milk Good For Pigeons??
  
    Some milk products contain little or no lactose, and these may be safely fed to birds. And actually, these products (cheese and yogurt) are a good source of calcium for birds.







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