Answer:
Biological energy conversion in mitochondria is carried out by the membrane protein complexes of the respiratory chain and the mitochondrial ATP synthase in the inner membrane cristae. Recent advances in electron cryomicroscopy have made possible new insights into the structural and functional arrangement of these complexes in the membrane, and how they change with age. This review places these advances in the context of what is already known, and discusses the fundamental questions that remain open but can now be approached.
Mitochondria are the powerhouses of the cell. In all eukaryotes that do not depend on photosynthesis, the mitochondria are the main source of adenosine triphosphate (ATP), the energy-rich compound that drives fundamental cell functions. These functions include force generation (for example, in muscle contraction and cell division), the biosynthesis, folding and degradation of proteins, and the generation and maintenance of membrane potentials. ATP is produced on a massive scale in the human body, amounting to 50 kg per day in a healthy adult, but considerably more in a long-distance runner. ATP is generated by the mitochondrial ATP synthase from ADP and phosphate ions. These are the products of ATP hydrolysis at the sites where energy is needed in the cell. Apart from cellular respiration and ATP synthesis, mitochondria have numerous other essential functions, including the production of NADH and GTP in the citric acid cycle, the biosynthesis of amino acids, heme groups and iron-sulfur clusters or the synthesis of phospholipids for membrane biogenesis. They also act in calcium signaling [1], stress responses [2] and generally as cellular signaling hubs [3]. Not surprisingly, mitochondria play a fundamental role in human health. Mitochondrial dysfunction is the cause of severe, often maternally inherited diseases. Moreover, mitochondria are deeply implicated in apoptosis and ageing [4].
In many respects, mitochondria resemble α-proteobacteria, from which they are thought to have originated by endocytosis some 1.6 billion years ago. The most striking evidence of this evolutionary relationship is the close homology of bacterial and mitochondrial respiratory chain complexes. Mitochondria have their own genetic system, which uses a distinct DNA code that differs both from that of their bacterial ancestors and their eukaryotic hosts [5]. They have their own protein translation machinery, complete with ribosomes, tRNAs and associated protein factors that more or less resemble those of their bacterial ancestors. Very recently, the first high-resolution structure of a mitochondrial ribosome, determined by single-particle electron cryomicroscopy (cryo-EM), has revealed a fascinating patchwork of similarities to and differences from bacterial ribosomes [6]. Nevertheless, mitochondria make surprisingly little use of their specialized protein production machinery. In the course of evolution they have transferred up to 99 % of their genes to the nucleus. Today, the vast majority of mitochondrial proteins are produced in the cytoplasm and imported into the organelle by an elaborate set of protein translocases [7]. In humans, only 13 mitochondrial proteins are organelle-encoded, all of them central, hydrophobic subunits of respiratory chain complexes or of the ATP synthase.
Mitochondria are highly dynamic [8]. In the cell, they form a tubular network that constantly changes by division and fusion (Additional file 1). Both processes are accomplished by multi-component molecular machineries that include a number of dynamin-related GTPases [9, 10]. When mitochondria are isolated from cells, the network breaks up into fragments that spontaneously reseal. Isolated mitochondria are fully competent for respiration and ATP synthesis [11]. They maintain their membrane composition, organization and membrane potential, as well as the ability to fuse [12] and to import proteins [7]. We owe much of what we know about mitochondria and how they work at the molecular level to in vitro studies with isolated mitochondria, or even mitochondrial membrane fractions, which still carry out oxidative phosphorylation and ATP synthesis [13].
The composition of mitochondrial membrane consists of several proteins and phospholipids.
The major phospholipids in the mitochondrial membranes are phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylserine (PS), and phosphatidic acid (PA), as in cell membrane.Phosphatidylglycerol (PG) and cardiolipin (CL), are exclusively components of mitochondrial membrane.The composition of a eukaryotic cell membrane comprises of phospholipids, proteins, carbohydrates and cholesterol or sterols.
What is a cell membrane ?
The cell membrane is a biological membrane that separates the interior of all cells from the outside environment and protects the cell from its environment.
The eukaryotic cell membrane is a bilayer of phospholipids which is semi-permeable in nature. The mitochondria is a double membranous structure, in which the inner membrane is of crucial importance. It is highly semi-permeable (unlike the outer membrane) and consists of various proteins that are involved in the oxidative phosphorylation.To know more about cell membrane here
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I need a argument to: Differences in the structure of protein molecules affect how they connect to other protein molecules. This can result in different traits
Explain how a change in the environment can cause the disappearance of traits or possibly cause an extinction of a species.
Answer:
Changes in the environment may leave individuals less well adapted to compete successfully for resources such as food, water and mates. Sometimes an entire species may become unable to compete successfully and reproduce. These problems can lead to extinction.
PLZ I'M NOT TRYING YO GOT TO SUMMER SCHOOL I WILL BRAINLIST YOU
true or false All arthropods belong to the Class Insecta
true or false All rodents belong to the phylum Chordata.
true or false All amphibians belong to the class reptilia.
true or false All primates are mammals.
true or false A lion belongs to the genus Felis.
true or false All mammals are primates.
true or false All Insects and lobsters are arthropods.
Answer:
1.)true
2.)true
3.)true
4.)true
5.)true
6.)false
7.)false
Explanation:
Answer:
False: All arthropods belong to the Class Insecta
True: All rodents belong to the phylum Chordata.
False: All amphibians belong to the class reptilia.
True: All primates are mammals.
False: A lion belongs to the genus Felis.
False: All mammals are primates.
True: All Insects and lobsters are arthropods.
Hope this helps :)
What is NOT a function of a cell
wall?
A. shape
B. movement
C. support
D. strength
Answer:
B
Explanation:
How do we know that there will be no changes to our DNA because of this vaccine?
Answer: There will be no changes in the DNA. My brother and parents both got it and nothing happened to their DNA. But I can warn you that one of the vaccines will make you terribly sick if you have Coronavirus when you get the shot. I'm unsure tho lol
Explanation:
The nucleus is surrounded by a semipermeable membrane. What would happen if this layer were permeable to most substances?
A. The DNA in the nucleus would be protected from harmful substances
B. Enzymes would not be able to speed up reactions in the nucleus.
C. The nucleus would not be able to communicate with the rest of the cell.
D. Large molecules would be able to enter and damage the nucleus.
Answer:
D
Explanation:
If the layer of nucleus were permeable to most substance, then the large molecules would be able to enter and damage the nucleus.
What is nucleus?It is a membrane-bound organelle present in the centre of cell in which thread like structures called chromatins are present which condenses to form chromosomes contains genetic material (that carries genetic information from parents to offspring).It controls all function of the cell.The layer or membrane around nucleus is called nuclear membrane is semi-permeable in nature which means that only specific molecules and ions can move across it.If the membrane would become permeable, then movement of all types of molecules will occur which will disturb the homeostasis (maintaining balance) of cell and can damage the nucleus.Hence, the correct option is: D. Large molecules would be able to enter and damage the nucleus.
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y Sem 2
L 4.5.2 Test (CST): Computer-Scored Unit Test
Question 14 of 25
Why did DNA technology lead to more use of cladistics?
A. It showed that the Linnaean system was very accurate.
O B. It showed that most traits result from genetic drift.
O C. It showed that different looking animals are actually related.
OD. It showed that gene flow happens between populations.
SUBMIT
Answer:
The correct answer is - C. It showed that different-looking animals are actually related.
Explanation:
DNA technologies help in developing the lineage of the organisms and more use of cladistics. DNA techniques help in determining which animals were closely related by studying the genetic change.
It is used to established new evolutionary relationships between different-looking animals as minor genetic changes may lead to morphological changes.
Which planet has a longer day than year?
OVenus
O Neptune
O Earth
Answer:
VENUS
Explanation:
On Venus, one rotation on its axis takes the equivalent of 243 Earth days and the planet's orbit around the Sun takes the equivalent of 225 Earth days.
Answer:
Venus, I think
Explanation:
So outta these three, Venus is the closest to the sun, so the year is the shortest. Venus is also the planet with the longest day averaging at 116d 18h, so I think that's the right one. Sorry if this is wrong
hope this helps:|
An organism made up of only one cell is called...
A. multicellular
B. unicellular
Answer:
unicellular
Explanation:
Unicellular organisms are made up of only one cell that carries out all of the functions needed by the organism.
Answer:
Unicellular
Explanation:
Uni means consisting of one, and Multi means more than one (:
which of the following is good for a plant?
Answer:
c,d
Explanation:
hehe don't be mad at me
Can someone help I’ve been stuck at this question for the past 10 minutes
A _____ extinction occurs when many species go extinct in a relatively short period of time
Answer:
I think it's
A mass extinction occurs when many species go extinct in a relatively short period of time.
Explanation:
Mass extinction is usually defined as a loss of about three-quarters of all species in existence across the entire Earth over a “short” geological period of time. Hence, I think the answer is correct.
Answer:
The correct answer is Mass
Your lab group is assigned an unknown organism to identify to the level of phylum. You have it narrowed down to either Phylum Porifera or Phylum Cnidaria. Which feature would allow you to identify the phylum of your unknown creature
Answer:
The correct answer is - the presence of pores.
Explanation:
The name Porifera is a term that means pore bearer as these individuals are one cell thick with many tiny pores present on their body and some big openings as well. These small pores are one of the characteristic features of these organisms. It distinguished the Porifera phylum from the Cnidaria phylum. There are many other microscopic and behavioral features present to classify them but in the lab presence of pores is important.
What are carbohydrates composed of and what is their main function in the body
Answer:
The Bottom Line
Carbohydrates serve several key functions in your body. They provide you with energy for daily tasks and are the primary fuel source for your brain's high energy demands. Fiber is a special type of carb that helps promote good digestive health and may lower your risk of heart disease and diabetes
Explanation:
HOPE IT HELPS
Fruits grown in hot climates are usually less sweet than those grown in cooler temperatures. The high temperatures increase the rate of respiration in the plants, thus reducing the sugar content in some fruits. Why does increased respiration in the leaves and stems reduce the sugar content in the fruits of a plant
Answer:
The correct answer is - Sugars produced in the leaves are used as an energy source instead of being stored in fruits.
Explanation:
The high temperature in climate leads to an increase in the respiration rate in the plants so they require more energy in the process.
They produce sugars in the leaves which leads to a decrease in the sugar content in the fruit as energy is the primary focus in such situation to survive in high temperatures.
Explain why unreactive metals are good for making jewelry
Explanation:
Platinum, gold and silver are used to make jewellery because the metals used in jewellery are always be chosen on the basis of its reactivity. It should be unreactive so that the metal does not tarnish. Many metals used for jewellery are expensive as well because they are rare.
Do heterozygous individuals have two of the same allele?
Answer:
False.
Heterozygous means having two different alleles.
Answer:
Heterozygous individuals have two different alleles of a gene.
Explanation:
what do carbohydrates, proteins , and fats have in common using the model above?
Answer:
carbohydrates ,proteins and fat all have carbon, hydrogen and oxygen atoms
PLS GIVE BRAINLIEST
One of the following is not used as a means of artificial vegetative propagation method C A Stem cutting B Grafting Layering D Seed sowing
Answer:
d
Explanation:
seed sowing is the true answer i think
One of the following is not used as a means of artificial vegetative propagation method.
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The common types of artificial vegetative propagation includes cutting, layering, grafting, sùckering, and tissue culturing.[tex]\bold{ \green{ \star{ \orange{Hope\:it\:helps.}}}}⋆[/tex]
Which of the following is something mulching does NOT do?
A. it covers the ground
B. it takes nutrients from the soil
C. it keeps in moisture
D. it limits weed growth
In tall plants, (T) is dominant to small (t). If two plants heterozygous for tall fruit are crossed, what are the
possible genotypes of the offspring?
A- TT, Tt, and tt
B- Tt
C- TT, tt
D-Tt, tt
Answer:
possible genotypes of offsprings are A.
TT Tt and tt
Answer:
A- TT, Tt, and tt
Explanation:
Draw a Punnett square!
Which of the following accurately describes covalent bonds?
A. Covalent bonds are formed when atoms share one or more
electrons.
B. Covalent bonds are formed when atoms transfer one or more
protons.
C. Covalent bonds are formed when atoms share one or more
protons.
D. Covalent bonds are formed when atoms transfer one or more
electrons.
Answer:
A
Explanation:
A covalent bond consists of the mutual sharing of one or more pairs of electrons between two atoms. These electrons are simultaneously attracted by the two atomic nuclei. A covalent bond forms when the difference between the electronegativities of two atoms is too small for an electron transfer to occur to form ions.
Answer: The answer is A Covalent bonds are formed when atoms share one or more electrons
Explanation:
Which part of cell division is different in plant and animal cells?
A.cytokinesis
B.anaphase
C.mitosis
D.eukaryotic
Explanation:
Cytokines is different in plant and animal cells
All of the following are kinds of passive transport EXCEPT
A. diffusion B.facilitated diffusion C. osmosis D.ion channels
Answer:
C
Explanation:
What has constantly changing amount of salt in the water
Answer:
estuary
hope this helps
have a good day :)
Explanation:
what is the main event that happens during metaphase?
Purple flowers are an example of incomplete dominance between blue (B) and red (R) flowers. A purple flower is bred together with a red flower. What are the genotype percentages of their offspring?
Answer:
Purple = BR
Red = RR
B R
R BR RR
R BR RR
50% BR, 50% RR
Explain what causes acid rain to form and its negative effects on living and nonliving things.
Answer:
The rain containing excess of acids called an acid rain.
Explanation:
The rain becomes acidic because of harmful gases like carbon dioxide,
sulphur dioxide and nitrogen dioxide which are emitted as smoke from
vehicles and industries. These harmful gases dissolve in rain drops to
form carbonic acid, sulphuric acid and nitric acid respectively.
Effects of Acid Rain
Acid rain makes the water of lakes, ponds and rivers too acidic
due to which fish and other aquatic animals get killed.
Acid rain eats up the leaves of the trees gradually. By losing
leaves, the trees die. Acid rain also damages crop plants in the
fields.
Acid rain damages the metal structures like steel bridges, etc
when it falls on them.
Acid rain damages the surfaces of buildings and monuments made
up of marble.
Which of the following is one of the most abundant elements in all living
things?
A. Helium
B. Oxygen
C. Silver
D. Gold
Which of the following is a potential benefit of a disturbance to a
community?
O a decrease in availability of resources
o the community may be unable to recover
O some species depend on disturbances
O links between the native species break
Answer:
I'm pretty sure it is 'some species depend on disterbences'
The potential benefit of a disturbance to a community is that some species depend on disturbances.
Importance of disturbance in a communityCommunity disturbance can be defined as a force, which may be biological or non biological, that results in mortality of organisms or loss of biomass.
Different types of disturbance that can affect a community include:
fires, storms, diseases, volcanic eruptions, earthquakes, contaminant spills, and land clearing.Some species depends on community disturbance because the cleared habitat caused by the disturbance leads to species movement into the newly cleared area, that is, secondary succession.
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PLEASE ANSWER! 100 POINTS!
Which of the statements below is true about osmosis?
a. As the universal solvent, water loves dissolving solutes and will always go to a hypertonic area.
or
b. As the universal solvent, water loves dissolving solutes and will always go to a hypotonic area.