《区块链》课程考核答案,区块链课程考核试题答案
近年来，区块链技术受到了投资者和企业家的热捧，它被认为是新一代信息技术的基础。为了更好地了解区块链技术，我们对《区块链》课程进行了考核，以下是考核试题的答案。
首先，我们来看一下什么是区块链技术？区块链技术是一种分布式账本技术，它使用一种可验证的共识机制来保持数据的安全性和一致性。它可以用来存储和记录各种数据，如交易、资产、身份、智能合约等。
其次，我们来看一下区块链技术的优势是什么？区块链技术具有以下优势：1. 去中心化：区块链技术是分布式的，它不需要中心化的第三方机构来管理数据；2. 安全性：区块链技术使用共识机制来保护数据的安全性；3. 透明性：区块链技术使所有参与者都能够查看数据；4. 低成本：区块链技术可以减少传统系统中的交易成本。
第三，我们来看一下区块链技术的应用场景有哪些？区块链技术可以应用于金融、政府、医疗、物联网、供应链管理等多个领域。例如，在金融领域，区块链技术可以用来实现跨境支付、智能合约、资产交易等；在政府领域，区块链技术可以用来实现政府服务、数据共享、电子投票等；在医疗领域，区块链技术可以用来实现健康数据共享、药品追溯等；在物联网领域，区块链技术可以用来实现物联网设备的连接和管理；在供应链管理领域，区块链技术可以用来实现供应链可追溯性和可视性。
以上就是《区块链》课程考核试题的答案，通过考核，我们可以更深入地了解区块链技术，掌握它的优势和应用场景，从而更好地发挥它的作用。
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『一』Blockchain is the answer to the problem of risk control system
Finance has three elements: security, profitability and liquidity
Let’s take a look at the principles of this defensive design:
First, we need to do an evaluation. Let’s first look at the definition of risk assessment:
Before or after a risk event occurs (but it has not yet ended), the impact and possibility of losses caused by the event to people’s lives, lives, property, etc. quantitative assessment work.
In other words, risk assessment is to quantitatively evaluate the possible degree of impact or loss caused by an event or thing. From the perspective of information security, risk assessment is an assessment of the threats, weaknesses, and impacts faced by information assets (i.e., the set of information about an event or thing), as well as the possibility of risks caused by the combined effect of the three. sexual assessment. As the basis of risk management, risk assessment is an important way for organizations to determine information security needs and is part of the planning process of the organization's information security management system. We need to realize that people have motivations, while machines and programs only have instructions. This is an important difference between humans and machines.
The following are the problems faced in the process management of defensive design of risk control:
What is the object (or asset) to be protected? What is its direct and indirect value?
What potential threats do assets face? What causes the threat? How likely is it that the threat will occur?
What weaknesses exist in the asset that could be exploited by threats? What about ease of exploitation?
Once a threat event occurs, what kind of losses will the organization suffer or what negative impacts will it face?
What security measures should the organization take to minimize the losses caused by risks? ?
The process of solving the above problems is the process of risk assessment.
When conducting risk assessment, there are several correspondences that must be considered:
Each asset may face multiple threats
There may be more than one threat source (threat agent)< /p>
Each threat may exploit one or more system weaknesses
The risk control system is a system about motivation and process management. Motivation and process management are the basic logic of the risk control system. Have you noticed that these are all human designs. Human design is based on knowledge structure and empirical judgment. Based on the principles of cases and statistics, there is due diligence.
Yet inquiry is rooted in the uncertainty of space and time; inquiry is motivated by the desire to bring the future and the present into agreement. Please note that this is still a human design. Just as all investigation reports are written by people, the information and data that people refer to are also written by people. So, here comes the key point, can the programs set by humans be replaced by technology? This question may have been unanswerable in the past, but now it has an answer.
The answer may be blockchain.
『二』 How to define blockchain? What are the application scenarios of blockchain?
Many people now think that blockchain is a universal technology. , omnipotent, somewhat mythizing blockchain technology!
Regarding the definition of blockchain technology, American scholar Melanie Swann defined blockchain technology as an open, transparent and decentralized technology in her book "Blockchain: A New Economic Blueprint and Introduction" database.
Definition of Blockchain: Narrow VS Broad
As for the application scenarios of blockchain technology, it is natural to combine the differences between blockchain and other technologies. In terms of system characteristics.
Blockchain technology features include:
Blockchain is a global A database storage system that can be operated collaboratively in various places is different from traditional database operations where read and write permissions are in the hands of a company or a centralized authority (a characteristic of centralization). Blockchain believes that anyone with the ability to set up a server can participate. Nuggets from all over the world have deployed their own servers locally and connected to the blockchain network to become a node in this distributed database storage system; once joined, the node enjoys exactly the same rights as all other nodes With justiceservices (decentralized, distributed characteristics).
At the same time, people who provide services on the blockchain can perform read and write operations on any node in the system. In the end, all nodes around the world will complete the process again and again according to a certain mechanism. Synchronize in sequence to achieve complete consistency of data in all nodes in the blockchain network.
At the beginning of this year, the term blockchain began to enter everyone’s lives. From national leaders to aunts who dance square dances, everyone knows this term. This term is widely known by Bit Brought by coins.
As we all know, the first few dozen bitcoins could only be exchanged for one pizza. At its peak, it was more than 20,000 US dollars each, which has skyrocketed by more than a thousand times, which has also benefited a large number of wealthy people. Currently, there are blockchain The virtual currency generated by technology is gradually entering into everyone's life, and many people have joined the ranks of currency speculation. I often hear people say that if you buy the right currency a hundred times, a bicycle will become a sports car, and one coin will turn a young model. You can imagine how many of them are involved. Attractive.
Since 2008, various games applying blockchain technology have also become popular, such as development games (Network Letts Dog, 360 Block Cat), mining games (NetEase Planet, Virtual Earth, Gongxinbao), these are attracting everyone to join in the name of blockchain, and of course there are some that are really reliable, which requires everyone to identify them carefully.
The three words "blockchain" were completely ignited during the Spring Festival that just passed, and the limelight overshadowed everything else. Some people said that this was the arrival of a new era, and the past has become classic, while others said To say that everything is hype is ultimately a bubble.
In fact, blockchain technology is not a new concept. It has been applied to many industries, such as electronic signatures, as early as the past two years. Recently, the third-party electronic signature platform eShanbao revealed the latest progress of blockchain applications to NewSeed.
Currently, blockchain technology is mainly used in e-signing products for certificate deposit and certificate issuance. The application scenarios include copyright protection and online signing. , web page forensics, phone recording, email storage of evidence, etc.
Take the rights protection of online works as an example. Since online rights protection generally adopts the method of collecting evidence after the fact, real-time confirmation of rights is not carried out in the process of evidence generation, so the entire confirmation process is difficult. The copyright process is time-consuming, difficult and costly to obtain evidence, and extremely difficult to prove and trace the source. It cannot meet the characteristics of rapid dissemination and large quantity of online works.
eShanbao's new intellectual property protection solution based on timestamp + blockchain starts from the user's real-name authentication and solidifies the information generated in the process in real time. Electronic data, and through the time source service synchronized with the National Time Service Center, online works are stamped with a legally valid time stamp to prove that the electronic file was at a certain timeThe interval has not been tampered with. Blockchain technology can establish point-to-point trust in the network, ensuring that all blockchain nodes can record complete copyright confirmation and transaction records, and can trace their origins, truly realizing anti-repudiation and anti-tampering, and realizing a kind of distribution. trust infrastructure.
Founder and CEO Jin Hongzhou believes that the application of decentralized blockchain technology has greatly improved the efficiency of data storage and certification, and The credibility of the identity of the parties reduces the cost of trust, but it cannot replace the original centralized public key encryption technology. The two should complement each other. Through the combination of the two, it can provide users with real-time and reliable Confirmation plan.
Next, e-Shanbao will also focus on building a smart contract platform based on blockchain technology. Jin Hongzhou said that data storage, Issuing certificates is only a relatively superficial application based on blockchain technology. It is the first step to implement blockchain technology, and the realization of real smart contracts is the second step. "Smart contracts cannot simply be understood as electronic contracts. They refer to a process, from the conclusion of the contract to the confirmation to the final execution." Jin Hongzhou explained.
Through the following limited cases, I hope everyone can understand the actual performance of blockchain technology, thereby stimulating interest in such solutions.
1. Administrative Services
Over the centuries, the roles and responsibilities of public administration have not changed significantly – or rather, what has changed dramatically is actually the size of the data and the specific ways in which public agencies handle it. Although various digital technologies already exist to help collect and process data, issues such as anonymization, portability, and the immutability of large amounts of data remain unresolved.
Sasha Ivanov, founder, entrepreneur and CEO of Waves Platform and Vostok projects, said, "What the public administration currently lacks is a more convenient user experience (UX) for data use. To improve the user experience , we should introduce some kind of layer to it that acts as a trusted public environment that is transparent and can store data anonymously and immutably."
Governments are working on this by launching the U.S. Federal agency and enterprise-level initiatives such as the Federal Blockchain Initiative are gradually confronting the existence of such problems. The United States held its first federal government blockchain forum in July 2017, and the U.S. General Services Administration currently has more than 200 related use case repositories. Ivanov explained, “Distributed systems can really help us build such a reliable environment, improve our big data work, and even integrate all emerging technologies – including artificial intelligence and the Internet of Things. In fact, , whenever we face any kind of technology, it always embodies certain other technologies.The sum of techniques. ”
Now, the system supported by the blockchain can actually work - this view has been unanimously recognized by all experts and has become the most important theoretical basis. In other words, next we have to What we do is to create more production-ready solutions.
2. Payment services
The government needs to process transactions, many of which involve the exchange of funds with citizens. District Blockchain technology has huge potential application value in reducing the cost of fund transfers - including using new blockchain-based cryptocurrencies as intermediate transaction carriers, or using blockchain as a means of fund transfer, etc. Once a perfect solution is found , the business opportunities contained therein will be endless - especially for those who need to conduct frequent cross-border or Internet transactions.
The Jasper project was developed by the Bank of Canada to help it further think about central banks And how other financial institutions should implement payment operations between different banks based on distributed ledgers. The Bank of Canada has also developed its own digital currency variant "CAD Coin" to test the use of a certain national currency on top of the blockchain The feasibility of it.
This project brings an interesting conclusion, that is, we should say no to the proof-of-work public chain system. In an article titled "Jasper Project: Is a distributed batch payment system feasible?" "In the paper, the author observed that "Proof-of-work systems are not suitable for such large transaction processing systems because they assume that all transactions in the system require publicity and observability to a certain extent. ”
3. Digitization and Intellectual Property
The government is responsible for maintaining copyright records and databases. These records prove the ownership of intellectual property. A blockchain-based system allows various artists, Performers and writers can time-stamp their works and theoretically detect copyright infringements and even retain permanent records of rights. In fact, many governments have taken important exploratory steps in this direction.
Iran recently announced that it will deploy this technology. "Iran Financial Tribune" quoted Morteza Mousavian as saying that "the Digital Media Department of the Ministry of Culture has reached an agreement with a blockchain company to jointly design a usable A system for protecting online copyright. "He also added, "Relevant programs will soon be released to users in an easy-to-use manner. ”
This work is still in the early stages of exploration, but it provides corporate customers with the possibility of preserving records through replication technology. From a theoretical level, companies can use blockchain solutions for financial accounting, And discover the errors in real time.
4. Welfare distribution
The government has the responsibility to create a level playing field for citizens. Citizens who are chronically poor or economically disadvantaged certainly Government support and assistance is needed to ensureThey have the ability to sustain themselves and gain the ability to continually develop. However, welfare distribution is neither simple nor often straightforward. Problems such as corruption and impersonation have been wreaking havoc on various distribution channels within government schemes.
In China, the National Council of Social Security Fund is conducting early research on how to use blockchain technology to improve the delivery of national benefits to citizens. At the same time, India is also taking action. Andhra Pradesh and Telangana are already using blockchain to support their civilian resource supply systems.
It is said that many companies, including Microsoft, are also considering using the same technology. These solutions, which will touch individual employees and functional roles, are expected to gradually appear in small businesses in the near future.
5. Bidding activities
In order to build public infrastructure or provide related services, the government hopes to achieve economies of scale and competitive gains through bidding as much as possible. However, the bidding process is often not fair or transparent. Public procurement has long been a major scene of rampant corruption around the world. Transparency International noted that “many governments will award project contracts to a certain supplier in the absence of fair competition. This allows companies with greater political resources to improperly win over competitors; or companies in the same industry Bids will be negotiated in advance between companies, ensuring that each company gets a share of the tender. This will significantly increase the cost of delivering services to the public - we have found that corruption issues can increase project costs by 50%."
So, how can blockchain technology solve the bidding problem? According to Ivanov, “Unlike decentralized centralized systems, independent ledgers powered by blockchain will be able to improve bidding or anything else that needs to be tracked. Transparency of financial processes. The intervention of blockchain technology will help track the use of funds and ensure that they are paid out as expected and within the allowed time."
Currently, Japan’s internal affairs and The Ministry of Communications has announced a blockchain-based bidding system, which means that in industries with serious collusion problems, small and medium-sized enterprises are expected to usher in a more transparent bidding method and brighter development prospects.
Although quite a few of the cases mentioned previously are far from finalized, they do provide many possibilities for companies and governments. Of course, the key lies in implementation; and we should also look at all this with optimism, that is, although blockchain technology is often misunderstood, it is and will eventually find a direction in which it can exert its own energy!
< p> In layman's terms, the blockchain is like a dozen beacon towers on the Great Wall. If an enemy comes at one place, they will send out smoke. The other beacon towers will know about it and enter a defensive state together. In technical language, it is a distributed ledger. Each node keeps accounts separately. The failure of one or two nodes will not affect the entire network.
How is this distributed network different from the distributed servers of Google Network? Google Network's distributed servers still belong to Google Network and are controlled by their central scheduling algorithm. The distributed nodes in the blockchain do not know each other and have no legal relationship. You can just go offline and shut down if you want, but because of the currency rewards, there will always be someone who will turn on the machine as a new node to support the network.
After the popular and technical explanation, I hope you understand. So the first application scenario is finance. I put my money in Alipay. If Alipay doesn't recognize it one day, there's nothing you can do. But on the blockchain, it is useless if one node does not acknowledge it, because other nodes still have my records. The second is the contract. Nowadays, contracts are made on paper and are easy to be faked. But if they are put on the blockchain, they cannot be faked.
There are more application scenarios. It is recommended to check the top 100 digital Huobi online to understand the corresponding projects behind them and become a blockchain expert. .
Blockchain technology was first used in Bitcoin. Blockchain provides a reliable and trustworthy means of organizing data for cross-subject business scenarios. JD.com is essentially a supply chain company, and blockchain technology will be first used in many scenarios of the supply chain.
Blockchain is a decentralized technology. Blockchain can be applied to all products currently covered by the Internet.
The most popular application industry at present is the financial industry.
An application that has been implemented is product traceability. Alibaba and JD.com are already using blockchain technology to fully trace the origin of some of the products they sell. Consumers can trace the origin of the purchased products. There are also many blockchain applications in the digital advertising industry. Since traffic fraud in digital advertising causes losses of tens of billions of dollars every year, there are already blockchain application projects based on digital advertising, such as DCAD, which is based on blockchain. The digital advertising application of blockchain technology mainly solves the problem of traffic fraud
In the future, as the application of blockchain technology becomes more mature, it will be applied in many industries, creating a new ecosystem based on technological trust. Mode
The characteristics of blockchain are distributed accounting and decentralization, but the ultimate goal is to make people get along more equally. Technology is meaningful only when it serves human values, and technology that meets human value needs will develop. Therefore, blockchain is in line with human pursuit of freedom and equality, so its trend to become mainstream is unstoppable.
Currently, there are many blockchain gimmicks, which are basically used to issue coins. The newly launched ono is a decentralized, free and global social platform. Due to decentralization, your chat communications are peer-to-peer and the restNo one can look at it. In other words, your every word and deed will no longer be recorded and reviewed at any time like it is now on WeChat, QQ, and Facebook, freeing you from the trouble of surveillance.
In fact, blockchain technology can be used in any field. Information that previously required third-party confirmation can be completed online and confirmed at multiple nodes, making it difficult (almost impossible) to delete.
At present, blockchain is still in its infancy, and the technology is not mature enough, but it is also a better time to enter.
What is blockchain If you use non-technical terms to explain blockchain, blockchain is a place where data is stored. However, the data stored in the blockchain is safe and reliable and does not need to be managed by anyone, so In the Internet, a place where data and information are exploding, having such a place would be like a magical treasure.
If you ask what the blockchain can do, it is better to say what applications require the use of the blockchain. As mentioned earlier, blockchain is a safe place, so wherever data needs to be protected securely on the Internet, blockchain technology needs to be used. For example:
Because the use of blockchain technology can better protect the data of policyholders, in today’s Internet, data is value and wealth, so value protection and value transmission are the future development directions of the Internet. And blockchain technology can really do just that.
If there are any deficiencies, you are welcome to comment and correct me.
In a narrow sense, blockchain is a chained data structure that combines data blocks in a sequential manner in chronological order, and is cryptographically guaranteed to be non-tamperable and non-tamperable. Fake distributed ledger.
The two parties involved in the transaction do not need to know who the other party is, nor do they need a third party for trust endorsement. They only need to trust a common algorithm to establish mutual trust and conduct direct transactions.
Its characteristics are trustlessness and decentralization. The destruction of each node's ledger has no impact on the entire blockchain. The blockchain runs point-to-point payments without a center that may cheat, and the security is greatly improved. Improved, the entire transaction network has changed from a star structure to a point-to-point P2P structure.
In the future, blockchain will be used in many fields and will have a great impact on human life. . It can be widely used in fields ranging from digital currency to securities and financial contracts, medical care, games, artificial intelligence, smart contracts, Internet of Things, e-commerce, file storage and other fields.
1. Cloud storage
This is the statistics of current cloud storage on the Internet. In terms of volume, Google has the largest volume, which is 8,000PB. So what if we share the idle data on the Internet?
Starlight Cloud builds a blockchain data computing and storage lake through Starlight Chain, with a total storage capacity of 15,000P (approximately 15,728.64 billion G) in the future. This will be more than 10 times that of Alibaba Cloud's 1500PB! It is also more than four times the size of the Taizhou Storage Center, the largest storage lake in the world after expansion.
2. Medical aspects
Using blockchain technology to save personal medical records also retains personal medical historical data, which can be used when seeing a doctor or planning for your own health in the future. Historical data can be called directly. These data are highly private, and the use of blockchain technology also helps protect patient privacy.
『三』Where can I find the answers to Xindao Cloud Blockchain Training Platform
Xindao Cloud WeChat public account. According to relevant information, Xindao Cloud Blockchain Training Platform is a Chinese practical teaching cloud platform that mainly teaches users modern blockchain and Internet knowledge. The answer to Xindao Cloud’s blockchain training platform is that it can be used in Xindao Cloud. If the cloud WeChat official account is found, as long as the user follows the official account and sends a question, the answer and analysis of the question will be displayed.
『四』What does blockchain mean and how to make money
The meaning of blockchain and how to make money are as follows:
1. The meaning of blockchain: blockchain It is a piece of information that is finally stored in multiple places after being confirmed by multiple parties. It is a tool that can solve credit problems during transactions.
2. How to make money with blockchain:
(1) Provide blockchain technology services. Form a corporate team to specialize in the development and application of blockchain technology, and provide your technical results to companies in need for use, or develop corresponding blockchain technology based on the needs of service recipients. A simple understanding is to be a middleman.
(2) Use blockchain technology to issue coins. This method is that the company acts as an issuer and releases a certain number of virtual coins for others to invest, such as Bitcoin, Litecoin, and Dogecoin. At that time, if you wanted to become an issuer, in addition to having blockchain technology, you also had to apply for a series of filing documents and materials such as business qualification certificates and currency issuance qualification licenses from relevant regulatory authorities. Otherwise, if you don’t have these documents, it would be fraud. . However, successfully preparing these documents will still test the strength and capital of the company. If the funds are not strong enough, it will be difficult to sustain.
(3) Payment for blockchain knowledge. In the early days of the blockchain market, many people did not understand what blockchain was and wanted to participate, which inevitably gave rise to a payment market for blockchain knowledge. Since this year, many public accounts with the theme of blockchain have appeared, and many paid blockchain courses and small investment circles have been born.
(4) Register to receive free candies. Candy is a token that the blockchain project team rewards early users in order to attract more users to join early use and dissemination. Similar to the early "Didi", in order to cultivate a large number of early users, a large number of free taxi tickets were issued to users.
『五』Lesson 4 Cryptography in Blockchain Learning Summary
This isJoin Ulord in the fourth course of deep learning. Dr. Yang will lecture on cryptography issues in the blockchain. This course helped me understand a problem about public keys and private keys that has been bothering me. Between them What is the relationship? I got the answer in this study, and now I will share with you what I learned.
The public key and private key in the blockchain are two basic concepts in asymmetric encryption.
Public key and private key are a key pair obtained through an algorithm. The public key is the public part of the key pair, and the private key is the non-public part. Public keys are usually used to encrypt conversations, that is, messages or information, and can also be used to verify digital signatures signed with private keys.
The private key can be used to sign and the corresponding public key can be used for verification. The key pair obtained through this public key system can be guaranteed to be unique worldwide. When using this key pair, if you use one of the keys to encrypt data, you must use its corresponding other key to decrypt it.
For example, data encrypted with a public key must be decrypted with a private key. If a private key is used for encryption, the corresponding public key must be used to decrypt it, otherwise the decryption cannot be successful. In addition, in the Bitcoin blockchain, the public key is calculated through the private key, and the address is calculated through the public key, and this process is irreversible.
『Lu』 What to do if the credit card cannot be swiped at Xingyi Pay POS machine
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Energy conversion
Mitochondria are the sites where eukaryotes carry out oxidative metabolism. It is the place where sugars, fats and amino acids are ultimately oxidized to release energy. The common pathways for final oxidation that mitochondria are responsible for are the tricarboxylic acid cycle and oxidative phosphorylation, which correspond to the second and third stages of aerobic respiration respectively. Glycolysis completed in the cytoplasmic matrix and tricarboxylic acid cycle completed in the mitochondrial matrix produce reduced nicotinamide adenine dinucleotide (NADH) and reduced flavin adenine dinucleotide High-energy molecules such as receded flavin adenosine dinucleotide (FADH2), and the role of oxidative phosphorylation is to use these substances to reduce oxygen and release energy to synthesize ATP. During aerobic respiration, 1 molecule of glucose can produce 30-32 molecules of ATP after releasing energy through glycolysis, tricarboxylic acid cycle and oxidative phosphorylation (Considering that transporting NADH into mitochondria may require 2 molecules of ATP). If the cell's environment is deprived of oxygen, it will switch to anaerobic respiration. At this time, the pyruvate produced by glycolysis no longer enters the tricarboxylic acid cycle in the mitochondria, but continues to react in the cytoplasmic matrix (reduced by NADH into fermentation products such as ethanol or lactic acid), but does not produce ATP. Therefore, during anaerobic respiration, 1 molecule of glucose can only produce 2 molecules of ATP in the first stage.
Tricarboxylic acid cycle
Each molecule of pyruvate produced during glycolysis is transported across the mitochondrial membrane by active transport. After entering the mitochondrial matrix, pyruvate will be oxidized and combined with coenzyme A to generate CO2, reduced coenzyme I and acetyl-CoA. Acetyl-CoA is the primary substrate of the tricarboxylic acid cycle (also known as the "citric acid cycle" or "Krebs cycle"). The enzymes involved in this cycle are free in the mitochondrial matrix except for succinate dehydrogenase located in the inner mitochondrial membrane. In the tricarboxylic acid cycle, each molecule of acetyl-CoA is oxidized and produces reduced cofactors for the initial electron transport chain (including 3 molecules of NADH and 1 molecule of FADH2) and 1 molecule of guanosine triphosphate (GTP).
Oxative phosphorylation
Reducing molecules such as NADH and FADH2 (in the cytoplasmic matrix
The reducing equivalents can be obtained from the malate-aspartate shuttle system composed of antiporters or It enters the electron transport chain through the shuttle effect of glycerol phosphate). After several reactions in the electron transport chain, oxygen is finally reduced and energy is released. Part of the energy is used to generate ATP, and the rest is lost as heat energy. Enzyme complexes (NADH-ubiquinone reductase, ubiquinone-cytochrome c reductase, cytochrome c oxidase) on the inner mitochondrial membrane use the energy released during the process to pump protons into the mitochondrial intermembrane space against the concentration gradient. Although this process is efficient, there are still a small number of electrons that prematurely reduce oxygen and form reactive oxygen species (ROS) such as superoxide. These substances can cause oxidative stress and degrade mitochondrial performance.
When protons are pumped into the mitochondrial membrane space, an electrochemical gradient is established on both sides of the mitochondrial inner membrane, and protons tend to diffuse along the concentration gradient. The only diffusion channel for protons is ATP synthase (respiratory chain complex V). When protons pass through the complex from the intermembrane space back to the mitochondrial matrix, the electrical potential energy is used by ATP synthase to synthesize ATP from ADP and phosphate. This process is called "chemiosmosis" and is a type of assisted diffusion. Peter Mitchell won the 1978 Nobel Prize for proposing this hypothesis. In 1997 Nobel Prize winners Paul Boyer and John Wacker elucidated the mechanism of ATP synthase.
Storing calcium ions
Mitochondria can store calcium ions and work together with structures such as the endoplasmic reticulum and extracellular matrix to control the dynamic balance of calcium ion concentration in cells. The ability of mitochondria to rapidly absorb calcium ions makes them a buffer for calcium ions in the cell. Driven by the membrane potential of the inner mitochondrial membrane, calcium ions canIt is transported into the mitochondrial matrix by the one-way transporter present in the inner mitochondrial membrane; when exiting the mitochondrial matrix, it requires the assistance of sodium-calcium exchange proteins or through the calcium-inced-calcium-release (CICR) mechanism. When calcium ions are released, it causes a "calcium wave" accompanied by a large change in membrane potential, which can activate certain second messenger system proteins and coordinate the release of neurotransmitters in synapses and the secretion of hormones in endocrine cells. secretion. Mitochondria are also involved in calcium ion signal transduction during apoptosis.
Other functions
In addition to the main functions of synthesizing ATP to provide energy to cells, mitochondria also undertake many other physiological functions.
·Regulate membrane potential and control programmed cell death: When the inner membrane of the mitochondria contacts the outer membrane, a protein composed of hexokinase (cytoplasmic matrix protein), peripheral benzodiazepine receptors and voltage-dependent anion channels ( Permeability transition pores (PT pores) composed of multiple proteins such as mitochondrial outer membrane protein), creatine kinase (mitochondrial intermembrane space protein), ADP-ATP carrier (mitochondrial inner membrane protein), and cyclophilin D (mitochondrial matrix protein) Finally, the permeability of the inner mitochondrial membrane will be increased, causing the dissipation of mitochondrial transmembrane potential, leading to cell apoptosis. Increased mitochondrial membrane permeability can also release molecules such as apoptosis-inducing factor (AIF) into the cytoplasmic matrix, damaging the cell structure
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