Chapter 844 Returning to the Country

Bifang knows a very interesting hypothesis about the origin of mitochondria.

Mitochondria were once eukaryotic organelles of bacteria and were endosymbiotic with humans.

In short, mitochondria were an independent organism a long, long time ago. They combined with humans by chance and finally became a part of the human body.

To this day, it still has a certain degree of "independence".

The evidence is that mitochondria and human genomes are completely different.

The mitochondrial genome is 16,569 long and encodes 37 genes, mainly related to the respiratory chain.

The human nuclear genome is 3 billion long and encodes 20,000 to 30,000 genes, including all content.

There is no homology between the two in terms of sequence.

The genomes of other tissues in the human body are all human nuclear genomes.

The gold standard for modern biological classification and identification is based on genomes rather than appearance characteristics, because many classification methods in the past were prone to errors.

Some look different but are actually in the same genus, and some look very similar but are actually very far apart in classification.

For example, tree shrews that look like mice are actually close relatives of humans, while Tibetan mastiffs and teacup dogs look like completely different species. The latter is not even as big as the former's reproductive organs, but there is no reproductive isolation.

However, endosymbiosis is not parasitism, these are two different things.

Single-celled organisms need to survive and take in substances and energy.

Just like "big fish eat small fish, small fish eat shrimp", large cells also swallow small cells.

This process is called "endocytosis".

The endocytosis process is closely related to the fluidity of the cell membrane. The swallowed things will be wrapped in a layer of cell membrane and enter the cell. The cell will perform a series of operations to decompose and utilize them, and spit them out of the cell. The process of spitting them out is called exocytosis.

What if the swallowed cell is a small cell?

This small cell is swallowed but not digested, but coexists in the large cell. This is endosymbiosis.

Some genes can be absorbed and integrated by the human body, but once integrated, a new system is formed, which is no longer divided from each other and obeys the expression regulation of the entire system.

Now if the mitochondria are separated out, it cannot be restored to the original bacteria and the original life.

This situation is actually very common. There are many such imprints in the human genome.

Just like the virus that invaded the human genome millions of years ago changed the on and off mode of genes in human embryonic stem cells.

About 100 million years ago, a large, phagocytic archaeon swallowed an aerobic, smaller, ancestral prokaryote.

Swallowing is a problem, but you have to pay attention to safety. It would be bad if the swallowed organism killed you.

The ancestral archaeon may have a series of stress changes to protect itself.

For example, a large number of cell membranes invaginated to form a primitive endoplasmic reticulum membrane system, thereby limiting the activity of the swallowed bacteria.

The primitive endoplasmic reticulum membrane system further specialized to wrap the genetic material of the cell to form the nucleus.

The ancestral archaeon became the ancestral eukaryote.

Some of the swallowed aerobic bacteria were not only not digested and decomposed, but also gradually survived in the large, ancestral archaeon cells.

It may be that the aerobic bacteria think it is good to have a home, so they stay in the ancestral cells and don't leave.

Being a creature is also very simple. You can do whatever you want. Why bother?

And the ancestral cells can accept it. It is equivalent to raising a pet. Although you have to provide food and shelter, you can get the energy and products of glycolysis from the aerobic bacteria, which is not a loss.

Thus, the two organisms formed a mutually dependent symbiosis, which was beneficial to both sides.

In this way, in the long-term evolution process, the swallowed organisms transitioned from parasitism to symbiosis, and finally formed mitochondria.

The evidence supporting the above theory is mainly because the comparison between mitochondria and true bacteria found that they are similar in many places.

Similar size.

Proliferate by binary fission.

Have similar covalent, closed, circular DNA.

Ribosomes are similar in size and structure, and have the same sedimentation coefficient.

Protein synthesis can be inhibited by antibiotics.

In addition, the endosymbiotic theory can also explain why mitochondria have double membranes, but it may not be the same as most people think. The double membrane may come from bacteria.

However, this is only the most common and recognized academic hypothesis, not an ironclad case.

Bifang threw away the complicated thoughts.

It is useless to think more, anyway, it will be used in the end.

Using the enhancement coupon, the same process as before appeared in my mind. This time, the enhancement is more subtle than the muscle control enhancement.

Instead of getting hot, it feels like entering a cool autumn.

After everything was over, Bifang had a lot of extra information in his mind, and he suddenly realized the direct effect of this voucher.

Improve and optimize the energy supply efficiency of mitochondria, and further improve the efficiency when the body is in a state of crisis.

Simply put, it is a burst of energy.

Similar to the secretion of adrenaline in a crisis, a person's strength, speed, and reaction will be enhanced, and the mitochondria at this time also have the same effect.

It's like taking a double dose of adrenaline, which can burst out stronger power and energy.

As for whether there is an additional effect of prolonging life, this is unknown.

Bifang himself tends to exist, after all, the system's enhancement has always been powerful.

"Huh."

With a long sigh of relief, Bifang felt unprecedented comfort, and at the same time his eyelids became heavy, and he felt a little drowsy.

The sun had not set yet, but Bi Fang still chose to go to bed.

In the evening, a staff member called Bi Fang outside the tent to have dinner.

Bifang opened his eyes in a daze. His sleep was interrupted midway, and he was still very sleepy, but his gurgling stomach also protested.

After a brief struggle, Bi Fang chose to refuse, saying that he still wanted to rest.

If he agrees, he can't come back to sleep after eating. Those professors will definitely invite Bi Fang to talk, and then he won't be able to go back for hours.

Bi Fang has experienced this experience many times and is deeply touched by it.

Bi Fang didn't get up until noon the next day.

I woke up feeling refreshed and washed up just in time for lunch. There is no happier moment than this.

After feeding Alpha some fodder, Bi Fang set off for the canteen.

Inside the large white tent, simple square dining tables were arranged neatly. People came one after another to cook in front of several large stainless steel pots and then choose a seat to sit down.

Bi Fang ordered a double portion by himself and chose a corner to sit down. Although it was not enough for him, there was no room for more food on one plate.

There is no need to bother others to wash more dishes. It’s free anyway and you can come more often.

"How is your rest, Mr. Bi Fang?"

As soon as Bifang sat down, Waziri also sat on the opposite corner of him with a dinner plate, scooping hummus with a spoon and saying hello.

Waziri did have the idea of ​​entertaining Bi Fang yesterday, but the other party did not come.

But even though he didn't come, no one had the idea that he was ignorant of current affairs. Anyone who walked in the vast desert for more than two months wanted to have a good sleep after it was finally over.

It would be stupid to have to drag the other person up to socialize. Moreover, it is even more understandable when I heard that the other person drifted at sea for more than a month before crossing the Sahara.

"Very good, this is the most comfortable sleep I've had in the past three months." Bi Fang gave a thumbs up, and at the same time picked up a squab, chewing it raw with the skin, meat and bones, making his mouth water.

I have been hungry for twenty-four hours, and eating such a big meal is extremely satisfying. It is like swallowing a large glass of ice water when you are thirsty on a hot summer day, or like drinking a mouthful of hot air on a cold winter day. Steaming mutton soup.

Egypt is a typical Arab country that believes in Islam, so it is almost impossible to find pork and related foods, and it also does not eat any animal offal or undercooked food, so food such as sashimi is completely unavailable in Egypt. market.

Alcoholics will also suffer when they arrive in Egypt, because local drinks are non-alcoholic and Egyptians prohibit alcohol.

Although there are many taboos, they cannot affect the Egyptians' love for food at all.

The local taste is strong, with chili, curry, pepper, etc. being used in most dishes, and Egyptians like rich, burnt and soft food.

In this way, the taste is more suitable for Bi Fang's stomach.

Plus the food here is pretty plentiful.

With a combination of scholars and government workers, the food here cannot be bad, with all kinds of meat available.

Seeing Bifang swallowing heavily, Waziri's smile became even bigger.

Almost everyone has a side that likes Amway in their heart. If you recommend something you like to others and receive praise, you will get a sense of recognition.

At this time, Waziri felt a touch of joy in his heart.

"Roasted pigeon is a delicacy that the groom must eat when we get married. We stuff rice and broad beans into the belly of the squab. The roasted pigeon meat is tender, juicy and fragrant."

“Another way to make it is to put pigeon meat, onions, tomatoes and rice in a clay pot to make a stew.”

Bi Fang gave a thumbs up, swallowed a piece of pigeon wing and bones, and praised: "I will definitely give it a try when I have time."

“Our kebabs here are also good and very popular. They use the best lamb and brush it with a mixture of salt, pepper, olive oil and other seasonings, then cut it into small pieces and thread it on an iron skewer. The grilled meat skewers are golden, fragrant, and very juicy, and you can even dip them in the sauce when eating. ”

Waziri went aside and came back with a plate of kebabs.

Bi Fang had not seen this thing over there before, so he thought it was a "small stove" given to him by the other party.

For such formalistic things, Bifang just wanted to say.

More!

Bi Fang picked it up and gnawed it unceremoniously. The mutton was minced, seasoned with spices, and then grilled on a skewer. The roasted meat was so fragrant that it made your index fingers tick.

You can also drink a bowl of Molokia after eating.

A green soup made from mallow. Mallow leaves are mashed and boiled together with mutton, chicken, or rabbit meat, butter, green onions and other foods. The cooked mallow soup is a bit sticky, but it tastes delicious. , you can also use garlic to enhance the flavor when eating, which is very satisfying when paired with grilled skewers.

Then, under Waziri's astonishing gaze, Bifang ate all the skewers for multiple people and burped in a slightly indecent manner.

"I have long heard that Egypt is the land of spices, and it is indeed well-deserved!"

"I saw many different types of spices along the way, but unfortunately there were not many and I couldn't collect them."

"That's such a shame."

Waziri is not without regrets.

The Sahara is not completely deserted, although most of the world's farmers and city dwellers consider it an empty expanse that is difficult to farm, inhospitable and of little use to humans today.

But this land is not worthless to humans.

For thousands of years, this dry land has produced something extremely valuable, that is, spices.

Spices are very useful, they can be eaten, smelled, and pickled mummies.

Like cinnamon and star anise, they can not only be used for cooking, but also for making sachets.

When it comes to the history of using incense, when the Egyptian pharaohs began to play with spices, European nobles were still picking fruits.

After observing the Egyptian murals, you will find that the pharaohs' daily life is probably: holding a spice jar today, holding two tomorrow, and showing off to people who don't have it the day after tomorrow, which is simply fun.

Chemical ecologists believe that high temperatures and dry climates are more beneficial than harmful to the evolution of aromatic plants containing benzene ring compounds.

The fragrance emitted by the leaves of many aromatic plants may help them resist heat, drought and damage from herbivorous animals.

The content of this fragrant, highly volatile, and fleeting chemical in plants in dry climate zones is more concentrated than that in plants elsewhere.

Coupled with the body odor problem of Egyptians, this desert has become the most suitable place for the growth of the world's most powerful aromatic plants under artificial cultivation.

So along the way, Bifang collected a lot of spice seeds, but unfortunately there were many types and few quantities, so he was reluctant to use them for cooking.

Now he is finally satisfied.

After dinner, Waziri and Bifang talked about their travel experience, and told Bifang about the subsequent excavation of the ancient tomb before leaving. Before leaving, he once again invited Bifang to participate in today's bonfire dinner.

Bifang originally planned to refuse, but when he heard Waziri say that there would be roasted whole lamb in the evening, he could not refuse the kindness and could only reluctantly agree.

The next day, Bifang, who was satisfied, chose to leave on the truck transporting fresh water.

As for Alpha, he asked another truck to check it in.

Before leaving, Bifang also gave Waziri a flint dagger he made by himself as a thank you for the hospitality over the past two days.

Finally, after playing in Cairo, the capital of Egypt, for two days, Bifang bought a plane ticket and returned to China, while Alpha was specially checked in and would arrive in another day.

As soon as he opened the door, Bifang heard the clacking sound of claws hitting the floor.

Then several furry dogs rushed down the stairs like a white torrent, all running towards Bifang.

Apparently, after three months of not seeing each other, although there was an aunt to feed him every day, Fugui and Wangcai had not forgotten their old master.

Then Bifang felt that he was trapped in a sea of ​​long hair, almost unable to breathe, and there were slippery tongues everywhere.

With six attacks, even a wilderness master like Bifang could not break free for a while. After several minutes, he felt that the enthusiasm of the dogs had subsided a little.

"That's enough." Bifang stretched out his hand and pinched Goudan's mouth, "I'll take you to the club tomorrow to have fun and meet new friends by the way."

Alpha is too big to be kept at home.

Therefore, Bifang plans to place it in the club. Anyway, it is not far away and he can visit it often. I think it also prefers a more open environment.

Cheetahs are very timid and shy animals, especially young cubs. In severe cases, it may even affect their "love". In order to solve this problem, some zoos will let it make friends with dogs