Mitochondria

Mitochondria Mitochondria: Mitochondria is an organelle which is commonly found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner layer being folded inward to form layers. Characteristics: The term mitochondrion is coined by C. Benda. These are energy converting organelles, which are present in virtually all eukaryotic cells. Structure of Mitochondria: The mitochondria are covered with two membranes: Outer membrane: The outer membrane is fairly smooth. It has special proteins embedded into the membrane called porins which are intrinsic proteins responsible for the transport of molecules across the membrane. The outer membrane protects the organelle, and porins allow free passage for various molecules into the inner-mitochondrial space of the mitochondria. Mitochondrial porins are voltage dependent anion-selective channels that allow the passage of small molecules across the mitochondrial outer membrane. Inner membrane: Inner membrane is highly convoluted; forming folds called cristae. The inner membrane is also very impermeable to many solutes due to the high content of a phospholipid called cardiolipin. The cristae greatly increase the inner membranes surface area. The two faces of this membrane are referred to as the matrix side and the cytosolic side. Inner membrane contains enzymes complex called ATP synthase (also called F0-F1 complex or oxysomes) that make ATP. Hydrogenosome and mitosomes: Some primitive protists such as Trichomonas vaginalis lack mitochondria. These protists contain a specialized organelle, involved in synthesis of ATP abd hydrogen, called the hydrogenosome. These are the site of fermentative oxidation of pyruvate, coupled with ATP production via substrate level phosphorylation. Like mitochondria, hydrogenosome are surrounded by a double membrane and produce ATP. In contrast to mitochondria, hydrogenosomes produce molecules hydrogen through fermentations, lack cytochromes and usually lack DNA. Mitosomes, organelles of mitochondrial origin, are double membrane bound organelles found in some unicellular eukaryotes, including Entamoeba histolytica and microsporidia. The mitosome has been detected only in anaerobic organisms that do not have mitochondria. Functions of mitochondria: Mitochondria has an important function is to harvest energy. The simpler compounds obtained from nutrition are carried to the mitochondria where they are further processed and converted to charged molecules. These charged molecules again chain with oxygen and produce ATP molecules. This process is referred as oxidative phosphorylation. Mitochondria aid the cells to sustain proper concentration of calcium ions within the partitions of the cell. The mitochondria also supports in building certain fragments of blood and hormones like testosterone and estrogen. The mitochondria in liver cells have enzymes for detoxifying ammonia. The mitochondria also play an important role apoptosis (also called as programmed cell death). Irregular death of cells due to the deformity in mitochondria can affect the function of organ. Targeting of mitochondrial proteins: Mitochondrial proteins are synthesized by cytosolic as well as matrix ribosomes. About 99% of mitochondrial proteins are encoded by nuclear genes and are synthesized as precursors on cytosolic ribosomes. Proteins synthesized by cytosolic ribosomes are translocated into mitochondria post- translationally. Proteins imported into mitochondria may be located into outer membrane, the intermembrane space, the inner membrane or the matrix. Mitochondrial protein import requires membrane receptors and translocons. Import is initiated by the binding of a mitochondrial targeting sequence to an import receptor in the outer mitochondrial membrane. Two distinct translocation complexes that mediate translocation are situated in the outer and inner mitochondrial membranes, referred to as TOM (Translocase of the outer membrane) complex and TIM (Translocase of inner membrane) complex. Both translocases have to cooperate tightly to promote protein translocation. The TOM complex consists of seven different subunits. The receptors Tom20, Tom22, Tom70 recognize precursor proteins and transfer them to the central component, the channel forming Tom40. Three small Tom proteins Tom5, Tom6, and Tom7, are tangled in the association and dynamics of the TOM complex.

Choosing Your English Tutor

Choosing Your English Tutor How to Choose the Right English Tutor for Help with English Revision ChaptersDefine Your Criteria for an English TutorTeaching Experience: How Important is It?Contacting Potential TutorsWith more and more people offering to share their valuable knowledge as tutors, those looking for private tuition have the pick of the bunch!But making the decision on who to hire is not always easy â€" especially when there so many things to consider.Some people have a relaxed approach to their search, and don’t have a strong preference to being taught in a tutoring centre or by a home tutor, to name just one example.In some ways, it helps to have clear preferences, since this will help you narrow down your search.No matter where you look or who you choose to be your English tutor, the proof of the pudding is definitely in the eating!In other words, if you put enough work into researching and choosing your tutor, you’ll start to see positive results from the very first session.The world of one to one tutoring is a diverse one, meaning that each tutor possesses the ir own unique set of skills which they have gained from experience.For this reason, it isn’t compulsory for a private English tutor to have a teaching qualification.However, this does not mean that their tuition will be sub-par by any means.For instance, many English undergraduates offer their tutoring services to GCSE students who need support with exam technique â€" something undergrads will have experienced first-hand.Find a GCSE English tutor to get all the help for English you need.It’s important to weigh up the pros and cons in every aspect of your decision to make sure you follow the path that best suits the needs of the learner.Discover ten good reasons to hire a private English tutor!Having a short chat with each candidate is advised, as you’ll get a feel for their personality â€" which is important since as compatibility plays a major role in the success of one to one learning.Here is our advice for anyone about to take their first steps to finding the ideal tutor.Te aching ArrangementsPrivate tuition is accessible through many routes.Some parents choose tutoring centres to maintain a healthy distance between learning and leisure at home, so that children see the academic support as a part of their education, rather than as an interruption to their home life.Others prefer to welcome tutors into their home and create a relaxed learning environment for the student.The in-home arrangement is most effective for tutees who have a negative attitude towards the education system, as it shows them that learning can take place without the pressure of speaking up in front of a class and having to compete with other pupils.Find out other benefits to private tutoring in English!One-to-one tutoring: a safe learning environment ¦ source: Pixabay - pixel2013Another option is online tutoring, which has seen a recent growth in popularity with the rise of new technology.Online tutoring isn’t so different to home tutoring in that it is delivered on a one on one basis, however, since tutors and their students can be thousands of miles apart, they use a webcam and microphone to communicate.Despite the lessons not being taught in-person, technology allows users to share and view documents with each other, and teachers can even watch their pupils complete quizzes and worksheets â€" just like in-home tutoring.Learning with an online tutor does have its benefits. For instance, parents, pupils and tutors alike save a lot of time travelling between each other’s houses.Price per LessonThe majority of British families don’t pay for their children’s schooling, so the price of £40 for one hour with certain tutors can come as a shock.Unfortunately, private tutoring has long been perceived as something reserved for those who can afford such prices. But the market for one to one tuition is changing, and a rise in competition between tutors means lessons are now more accessible than ever!So, don’t be afraid to set a budget for yourself before you start looking.Specialist TutorsSome parents and students look for a tutor for a specific reason.For example, they may want someone to help with exam preparation in the run-up to GCSE season.For this kind of tutoring, where the tutor is brought in for a very specific reason, you’ll need to find tutors who can specialise.This is also the case for many parents of pupils living with Specific Learning Difficulties (SpLDs) such as dyslexia, which make studying English particularly challenging.Luckily, tutors who either specialise in teaching pupils with SpLDs or have experience in it are more common than you’d expect.So, there’s no need to worry â€" if you’re on the hunt for a tutor who has the skills to help students overcome obstacles such as dyslexia, rest assured that help is available.Teaching Experience: How Important is It?A significant portion of the tutoring community comes from a teaching background.Be it teaching in a school, sixth form or even lecturing at a universit y, the wealth of experience shared by qualified teachers makes them attractive for tutees.On the other hand, however many years of formal teaching experience a teacher possesses, sometimes their skills don’t meet the needs of the student.Who better to teach students than students themselves? ¦ source: Visualhunt - StartupStockPhotosStudents who feel disillusioned by their school life may benefit from a tutor who can identify with them as a learner within the education system rather than someone who they view as ‘just another school teacher’.This is where A Level English students and English undergraduates come in.Since these types of tutors have recent experience of being a student in the school system, they can identify with pupils on a personal level, as well as advise them on effective revision methods, exam technique and essay writing.When it comes to teaching experience, you should weigh up the pros and cons of each side.It’s important to bear in mind that teaching a c lass of 30 is quite different from delivering one to one tuition, so in many ways, tutoring experience is more valuable than formal teaching skills.We recommend that you ask your potential tutors a few questions before you make a decision, and a question on tutoring experience should be top of the list â€" no one wants to spend their hard-earned money on an inexperienced tutor.One of the advantages to finding a tutor through a tutoring company or platform is that they do the work for you, so you should have a good idea of their level of experience before you make first contact, removing some stress from the process.Contacting Potential TutorsOnce you have found a few tutors you like, you may want to contact each one of them before making a final decision.What would you like to know about each tutor? ¦ source: Pixabay - TeroVesalainenGetting in touch over the phone or via email provides an opportunity for you to find out exactly what you need to know about each tutor as well as gett ing a feel for their personality and whether it would be compatible with that of the learner.If you need a little inspiration, here are some example questions:How much private tutoring experience do you have?Can you provide references?What relevant qualifications do you hold?Do you specialise in any area of English (e.g. GCSE exam preparation)?What is your availability?How do you usually deliver your lessons?Do you already have experience of teaching a child like mine?These first conversations are crucial in finding out if the tutor is right for you before study begins â€" so make them count!