Distinguish between the structure of pyrimidines and purines. explain why adenine bonds only to thymine.

Answers

Answer 1

Pyrimidines have a single ring structure. Purines have a double ring structure. Adenine and thymine bind together as they’re complementary base pairs to one another, and form 2 hydrogen bonds upon binding

Answer 2

Final answer:

Pyrimidines, such as cytosine and thymine, are single-ringed structures, while purines, like adenine and guanine, are double-ringed. Adenine bonds only to thymine because they can share two hydrogen bonds, maintaining DNA's stable helix structure.

Explanation:

Distinguishing Between Pyrimidines and Purines

The structure of DNA nucleotides includes two distinct types of nitrogenous bases known as pyrimidines and purines. Pyrimidines are single-ringed structures and include cytosine (C) and thymine (T). In contrast, purines are double-ringed structures represented by adenine (A) and guanine (G).

When it comes to the bonding of these bases, adenine forms bonds only with thymine due to the ability of these to share two hydrogen bonds. This selectivity in bonding is also facilitated by the way DNA structures its nucleotide pairings—one purine with one pyrimidine—providing the necessary spacing to maintain the helix's integrity. The double-ring of a purine and the single-ring of a pyrimidine together form a pairing of a consistent shape and size, critical for the DNA structure. For this reason, adenine cannot pair with another purine such as guanine because it would create too much spatial hindrance, nor can it pair with another pyrimidine like cytosine due to excessive spacing.

So, adenine bonds only to thymine due to their matching ability to create two hydrogen bonds and the structural conformity that results when a purine is paired with a pyrimidine, thereby maintaining the optimal width of the DNA helix.

Related Questions

What is the species name of a frog that is between 1.5 and 6 inches long, has warts on its skin, and has a triangular mark between its eyes? question 3 options: bufo boreas litoria caerulea pseudacris crucifer acris crepitans?

Answers

What is the species name of a frog that is between 1.5 and 6 inches long, has warts on its skin, and has a triangular mark between its eyes?

Bufo boreas

Acris crepitans

Litoria caerulea

Pseudacris crucifer

-->Acris Crepitans is the correct answer.

Bacitracin blocks the transport of nag and nam across the cytoplasmic membrane to the cell wall. like other antimicrobials that block cell wall synthesis, this would result in weak cell walls and __________.

Answers

Bacitracin blocks the transport of nag and nam across the cytoplasmic membrane to the cell wall. Like other antimicrobials that block cell wall synthesis, this would result in weak cell walls and cell lysis. Antimicrobilas that act by inhibiting cell wall synthesis include beta-lactams, vancomycin and cycloserine and isoniazid and ethambutol among others. They prevent bacteria from increasing amount of peptidoglycan, they have no effect on existing peptodoglycan layer and therefore are effective only for growing cells.

Final answer:

Bacitracin is an antibiotic that inhibits bacterial cell wall synthesis, causing the cell wall to weaken and eventually leading to cell lysis or the bursting of the cell due to osmotic pressure. This means that the bacitracin is particularly effective against certain types of bacteria, while not harming human cells. It is commonly used in topical ointments due to potential kidney damage from prolonged use.

Explanation:

Bacitracin is a peptide antibiotic that inhibits bacterial cell wall synthesis by blocking the movement of peptidoglycan precursors, N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM), across the cell membrane. The cell wall becomes weak due to insufficient peptidoglycan, a major component of the cell wall in bacteria. This results in cell lysis, where the cell bursts due to osmotic pressure because the cell wall can't hold the cell contents.

Bacitracin, like other cell wall synthesis inhibitors such as B-lactams and glycopeptides, exhibits selective toxicity as it targets a feature not present in human cells - peptidoglycan in the cell wall. Antibacterials like bacitracin are effective and popular because they do not harm human cells at the same time as they kill bacterial cells, which makes them particularly potent against Gram-positive bacteria like Staphylococcus and Streptococcus commonly found on the skin. However, it's important to note that prolonged use of bacitracin can lead to kidney damage, so it is often used in combination with other antibiotics like neomycin and polymyxin in topical ointments such as Neosporin.

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Yesterday nadia consumed 250 grams of carbohydrate, 75 grams of protein, and 60 grams of fat. 57) what percentage of calories of her day's intake came from fat?

Answers

number of calories gained when eating different types of food differs. Some food types are more fattening relative to other types.
the number of calories consumed when eating carbohydrates -
- 4 calories/ gram * 250 g = 1000 calories
calories gained eating proteins -
- 4 calories/gram * 75 g = 300 calories
calories gained eating fats
- 9 calories/ gram * 60 g = 540 calories
total amount of calories consumed = 1000 + 300 + 540 = 1840 calories

percentage of calories coming from fats = 540/1840 *100% = 29.3 %

How do physical traits (adaptations) get passed on to offspring and inherited by a population?

Answers

Offspring inherit their physical traits from their parents. Each parent passes on one allele, and half of their chromosomes during sexual reproduction.

which of the following separates layers of different density?
A)Incline
B)Halocline
C)Thermocline
D)pycnocline

Answers

The answer should be D. Hope I Helped!

Answer:pycnocline

Explanation:

I just had a question that was the opposite, instead of asking density and the answer is pycnocline, mine was asking pycnocline and the answer was density

Answers

Insertion of a narrow flexible tube, or catheter, through a blood vessel into the heart to withdraw blood samples, measure pressures, and inject contrast medium for imaging purposes is called Cardiac catheterization. Cardiac catheterization is a procedure to examine how well the heart is working. A thin, hollow tube called a catheter is inserted into a large blood vessel that leads to the heart. It is normally performed if one has a disease of the heart muscles, valves, or coronary arteries. During this procedure, the pressure and blood flow in the heart can be measure and therefore a problem or a disease can be diagnosed; or the efficiency at which the heart is working.

The hormone epinephrine binds to β adrenergic receptors on smooth muscle cells of the bronchioles, causing them to dilate (increase in diameter). thyroid hormone is essential for the synthesis of β adrenergic receptors; therefore, in the absence of thyroid hormone, epinephrine cannot trigger bronchodilation. this concept is known as __________.

Answers

The answer is permissiveness.

Thyroid hormone exerts a significant effect on the ability of the smooth muscle cells in bronchioles to respond to other hormones, especially catecholamines (including epinephrine). Thyroid hormone binds to the receptors on the surface of the cells and allow more receptors to accept epinephrine, which in turn, allows bronchodilation.

Continuous cell lines differ from primary cell lines in that question 12 options:
a.viruses can be grown in continuous cell lines.
b.continuous cell lines can be maintained through an indefinite number of generations.
c.continuous cell lines always have to be reisolated from animal tissues.
d.continuous cell lines are derived from primary cell lines.
e.continuous cell lines are from human embryos.

Answers

Continuous cell lines differ from primary cell lines in that continuous cell lines are derived from primary cell lines.

Continuous cell lines can be propagated indefinitely, while primary cell lines have a limited lifespan.

Option (b) is correct.

Continuous cell lines differ from primary cell lines in that they can be maintained and propagated through an indefinite number of generations, whereas primary cell lines have a limited lifespan and eventually undergo senescence or cell death.

Continuous cell lines are derived from primary cell lines through a process called immortalization, where they acquire the ability to divide indefinitely. These cell lines are often used in research laboratories and biotechnology applications because of their ability to provide a continuous and consistent source of cells.

Unlike primary cell lines, continuous cell lines do not need to be reisolated from animal tissues repeatedly. They can be cultured in the laboratory under specific conditions, and they are widely used for studying cell biology, drug testing, vaccine development, and viral propagation, among other applications.

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Moss spores form inside capsules that break open and shoot spores into the environment. Which does not help carry these spores to new areas? water

rhizoids

animals

wind

Answers

It is a rhizoid. That is the outgrowth of root hair on the underside of the thallus which will help to anchor a plant in place.

Which of the following events encouraged Somali fishers to become modern-day pirates?

A. The Somali government's inability to protect its resources
B. Attack
s by international pirates on Somali fishers
C. The illegal entry of cargo ships into Somali waters
D. Legal fishing in Somali waters by international fishers

Answers

Answer:

Explanation:

Legal fishing in Somali waters by international fishers encouraged Somali fishers to become modern-day pirates. Therefore, option (D) is correct.

Who were Somali fishers?

Somali fishers are individuals who work in the fishing industry in Somalia, a country located in the Horn of Africa. Due to a lack of effective government control and the effects of overfishing by foreign fleets, Somali fishers have faced significant challenges in recent years. The depletion of fish stocks in Somali waters has made it difficult for local fishers to make a living, leading some to turn to piracy as a means of survival.

In addition, the activities of international ships, including illegal fishing and dumping of toxic waste, have further damaged the environment and the livelihoods of local fishers. The issue of Somali piracy has become a complex problem involving economic, environmental, and political factors.

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Where should the origin of jointed appendages be placed on the phylogenetic tree?

Answers

At the base of Arthropoda.

"what advantage do organisms that reproduce sexually have over organisms that reproduce asexually?"

Answers

Organisms that reproduce sexually have greater genetic and thus characteristic variations, and so, are able to withstand more selection pressures if they so happen to change or become greater. This increases the chances of survival for that species itself.

Organisms that reproduce asexually are genetically identical to each other. They are unlikely to withstand any changes in selection pressures.

Hope this helps! :)

Circulatory systems compensate for _____. circulatory systems compensate for _____. the problem of communication systems involving only the nervous system the need to cushion animals from trauma temperature differences between the lungs and the active tissue the slow rate at which diffusion occurs over large distances

Answers

Circulatory systems compensate for the slow rate at which diffusion occurs over large distances.

Diffusion is the process of molecules moving from a place of high concentration to a place of low concentration, which happens thanks to the chemical potential gradient, such as the concentration gradient (the difference in the concentrations). This process is used by our cells, for example, in the transport of oxygen, since it can diffuse through the cell membrane and into the cell, when the concentration of oxygen is higher in the intercellular space.
Diffusion is generally a slow process when it comes to large distances, so for example, oxygen would take a lot of time to get from one place in the body to another, since it would have to diffuse through millions of cells.
This is where the circulatory system comes into play. Thanks to the circulatory system, the oxygen can simply enter the blood flow, and be transported by the hemoglobin in the red blood cells from our lungs to all the cells in our body much faster. Same goes for different molecules that the circulatory system transports, like nutrients, amino acids, carbon dioxide, hormones. These are all transported throughout our body at a rate much faster than the rate of diffusion, and diffusion is used in the capillaries, at the target cells after the molecules have already been transported by the blood.

Final answer:

The circulatory system compensates for the slow rate at which diffusion occurs over large distances, facilitating efficient transport of materials within the body. Additionally, it also compensates for the limitations of having only the nervous system for communication by disseminating signals broadly to the body via hormones and other messengers.

Explanation:

The circulatory system compensates for the slow rate at which diffusion occurs over large distances, amongst other functions. Within the body, materials like oxygen, nutrients, and waste products need to be transported from one region to another. Relying on simple diffusion would be quite inefficient due to the slow rate at which it processes. Therefore, the circulatory system acts as a network of highways, speeding up the transport process significantly.

Furthermore, it's critical to understand that the circulatory system also compensates for the problem of communication systems involving only the nervous system. While the nervous system is crucial for fast and targeted responses, the circulatory system disseminates hormones and other signals broadly to the entire body. It’s a slower communication method, but it affects all parts of the body simultaneously, which can be beneficial for many types of responses.

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One of the characteristics of a nutritious diet is that the foods provide enough of each essential nutrient, fiber and energy. this principle of diet planning is called:

Answers

This principle of diet planning is called adequacy. An adequate diet provides the human body with energy and nutrients for optimal growth, maintenance and repair of tissue, cells and organs. Water, carbohydrates, fats, proteins, vitamins and some minerals comprise the six nutrient classes that are relied upon for performance of essential functions and activities.

A journal whose articles are critically reviewed by experts in the field is called a:

Answers

A journal whose articles are critically reviewed by experts in the field is called a: peer reviewed journal.

Peer reviewed journals also known as scholarly journals, are journals that contain articles written by experts and are critically reviewed by many other experts in the field before the publication of the journal in order to ensure that the article is of good quality. When reviewing the journals, the reviewers do not know the article’s author, so that the article fails or succeeds based on its own value and not the owner’s reputation.

This type of farming practice helps preserve soil conservation by planting crops on the tops of hills.

Answers

Ridge tillage.

Hope this helps!

-Payshence xoxo

Name one negative consequence of exponential human population growth.
greater biodiversity
increased pollution
longer life expectancy

Answers

The only negative option given is: increased pollution. Humans unfortunately cause pollution through producing garbage, driving cars, producing human waste (sewage) and growing crops and raising livestock. The more people there are, the more pollution results. It is worth noting that people in developed nations generally cause more pollution because they consume more per capita that people in developing nations.

Answer:

The correct answer is "B" increased pollution

Explanation:

got it on USAtestprep ;D

Structural unemployment can be caused by ____________.

Answers

It can be caused by fluctuations in the business cycle.

THE NEXT TIME, PUT THE OPTIONSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS !!!

Hope this helps ! Good Studying !

Photon

A minimum of 100 years of isolation is required for two populations to accumulate enough differences to be considered different species. true or false: a minimum of 100 years of isolation is required for two populations to accumulate enough differences to be considered different species.

a. True

b. False

Answers

false, it would not accumulate enough differences to be considered different species.

The iron in breakfast cereal is absorbed more readily when consumed with a glass of vitamin c–rich orange juice.

Answers

This question is obviously incomplete. However, it is true that vitamin C aids in the absorption of iron. There are different forms of iron in the diet, with some forms more readily absorbed than others. Soluble haem iron found in meat is the most readily absorbed iron. Non-haem iron is commonly found in the ferric form, and is not as readily absorbed. However, vitamin C can aid in the reduction of the ferric form to a ferrous form which is more readily absorbed.

The loss of a fetus before the 20th week of pregnancy is referred to as a(n) ___________. The medical term is spontaneous abortion, but the condition is not an abortion in the common definition of the term. A) toxemia. B) miscarriage. C) ectopic pregnancy. D) embryonic pregnancy.

Answers

I am pretty sure it is B, my second choice is D, its definitely not A or C.

I hope this helps you:)

the answer is mscarriage, b.

______________ is the tendency of new parts of the brain to take up the functions of the injured parts.

Answers

Answer:

Plasticity

Hope this helps

The ________ is the area of the brain where higher level thinking and self-regulation occur.

Answers

The Prefrontal Cortexis the area of the brain where higher-level thinking and self-regulation occur; the peak of overproduction takes place at about 1 year of age.

Prefrontal Cortex is the area of the brain where its the highest level thinking and self regulation occur.

Hope it helped!

Answer will be bold!

What is the term given to the genetic makeup of the organism?

Answers

genotype is the answer

During cellular respiration, energy is stored in the form of _______.
oxygen
water
ATP
food,

Answers

During cellular respiration, energy is stored in the form of ATP

During aerobic respiration, cells use oxygen to release the energy stored in glucose. This energy is temporarily stored in the form of ATP (adenosine triphosphate), and water and carbon dioxide are released as wastes.

If you looked at unknown cells under a microscope, what could lead you to correctly conclude that they are prokaryotic cells

Answers

The main difference between a prokaryotic cell and a eukaryotic cell is that the prokaryotic cell have no true nucleus instead its genetic material is just suspended in its cytoplasm termed as nucleoid. The nucleus when viewed under the microscope is a membrane bound which is easily distingushable compared to the nucleoid.

Another distinguishing feature is that prokaryotic cells are usually smaller than eukaryotic cells.

Tetrodotoxin (ttx) is a neurotoxin that blocks voltage-gated na+ channels. what will happen in an organism that ingests ttx? all of the above in sufficient quantities, it will be fatal in the organism. action potentials will be impaired. neurotransmitter release will be impaired.

Answers

This question is unfortunately incomplete. A neurotoxin that blocks voltage-gated na+ channels will have all of the effects listed: there will be impairment of action potentials and neurotransmitter release, and in sufficient quantities, the toxin will prove fatal to the organism.

Final answer:

Tetrodotoxin (TTX) ingestion impedes action potential generation by blocking voltage-gated Na+ channels, likely resulting in neurotransmitter release impairment, muscle paralysis, and in high volumes, fatal outcomes due to respiratory failure.

Explanation:Effects of Tetrodotoxin (TTX) on Neurotransmission

Tetrodotoxin (TTX) is a potent neurotoxin that can have a severe impact on an organism's nervous system by blocking voltage-gated Na+ channels. If an organism ingests TTX, it will interfere with the normal generation and propagation of action potentials, as those are reliant on the influx of sodium ions during the depolarization phase. In sufficient quantities, TTX can be fatal, causing impairment in the release of neurotransmitters and leading to paralysis, which includes the muscles involved in breathing, ultimately resulting in respiratory failure.

Neurotoxins like TTX demonstrate the critical roles that neurotransmitters and their receptors play in maintaining vital functions. Other toxins such as botulinum toxin, tetanus toxin, and d-tubocurarine have unique mechanisms but similarly disrupt neurotransmission, leading to paralysis or uncontrollable muscle contractions. For instance, tetanus toxin inhibits the release of inhibitory neurotransmitters like GABA, causing excessive muscle contractions and potentially death by asphyxiation.

Cases of toxin-induced neurological dysfunction underscore the importance of intact neurotransmission for overall health and survival. The study of these toxins has not only provided insights into neurological function but also has given rise to therapeutic applications, such as the use of botulinum toxin in small doses to treat certain medical conditions.

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Identify the two main regions of a typical mollusk's body

Answers

Head foot and visceral mass

Most of the mollusks species are gastropods. The body of the mollusk is made of shell and fleshy part. The fleshy part is divide into foot and visceral mass. Foot is a distinct feature of mollusk. They use it mainly for locomotion. The visceral mass involves the organs for circulation, digestion and other important processes in living organism. The visceral mass has two external flaps of tissue called as the mantle. It secretes calcerous shell and encloses a mantle cavity.

The main regions of a typical mollusk's body is head foot and visceral mass. The Mollusks are soft bodied invertebrates. They have 4 body parts that are head and foot, shell, visceral mass and mantle. The main two parts are the head and foot and visceral mass. The Visceral mass is where digestion, respiratory, reproductive and excretory are held. On the other hand the foot is used to give a sense of balance and the head is used to carry one or two tentacles.

Which structure provides a protective outer covering for bones and assists with fracture repair?

Answers

Periosteum is the thin yet tough outermost layer of bones. Its many collagen fibers support the bone and firmly connect it to the surrounding structures. Osteogenic cells in the periosteum play a vital role in the growth and repair of bony tissue.

Several atmospheric gases contribute to global warming: carbon dioxide, methane, and nitrous oxide. Considering this, which choice would do the LEAST to directly reduce atmospheric carbon dioxide. That is...

Answers

the answer is D.he conversion of restaurant grease to bio-diesel fuel for use by motorists.

D) the conversion of restaurant grease to bio-diesel fuel for use by motorists.

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100 POINTS GIVING BRAINLIEST!! How was the deadlock in the presidential election of 1800 finally resolved? Which weakness of the articles of confederation did the delegates to the constitutional convention want to address?A. The federal government did not have a legislative branch to pass new lawsB. State governments did not have enough power compared to the federal government.C. The federal government had too many branches to be efficient.D. State governments were more powerful than the federal government. The influence of indigenous populations, such as the original Mayan and Aztec civilizations, would most likely be seen in the works of A. American folk artists. B. artists such as Frida Kahlo and Diego Rivera. C. an eclectic artist such as William Merritt Chase. D. American artists living abroad. The balanced equation for photosynthesis is shown below. 6 CO2 + 6 H2O C6H12O6 + 6 O2 What best explains whether mass is conserved or not during photosynthesis? It is not conserved because the total numbers of H atoms and O atoms are not equal on both sides. It is not conserved because the total numbers of O atoms and C atoms are not equal on both sides. It is conserved because the total number of H atoms on each side is 1. It is conserved because the total number of O atoms on each side is 18. The traits of an organism are passed to its offspring on small coded strands of dna material called Find the surface area of this square pyramid. The base has area 1764 cm^2 and perimeter 168 cm. 4116 cm^2 4704 cm^2 31,038 cm^2 2940 cm^2 Which statement best describes the structure of Crossing Brooklyn Ferry? Assume is a design manager for a production company. he independently assigns teams, chooses projects, researches trends, and is able to work from home two to three days a week. he provides a status report to the design director once a month. based on this description, it's safe to say that job is high in which job characteristic?a. task significanceb. feedbackc. skill varietyd. autonomye. task identity The biggest air pollution threat to poor people is ____. a. smoke from burning forests b. dust blown into the air c. indoor air pollution d. badly maintained automobiles e. pollutants from industry What structural modification of the small intestine slows the movement of chyme through the lumen? 1)The wind blew through the trees2)The sea breeze on the beach was welcoming3)A gale wipped the flags in pieces Tell me from these three sentences which word has a neutral, positive and negative meaning?Pls answer this I will make u the BRAINLIEST!!! 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The octave introduces the speakers opinions about cities, while the sestet contradicts those opinions. D. The meter, iambic pentameter, mimics the sounds of natural elements while the lines describe an urban scene. About ________ percent of wais scores fall between 85 and 115. It is safe to thaw frozen foods at room temperature true or false Testicular cancer risk is highest for adolescents and men younger than age 35. to specifically address testicular cancer risk, a nurse should modify client teaching for male clients to include: choose the most appropriate strategy and then use it to solve the quadratic equation.7. (x-8)^2=1218. 2a^2=8a-69. x^2+12x+36=410. x^2-x+30=0 Which sentence uses an article that points out a general noun? A.You'll need some money for snacks.B.Where is the book I ordered?C.Look at those raspberries.D.Nathan and I had an appointment. A pool pump fills 1/6 of the pool in 1/3 hour. How much of the pool is filled in one hour Which of these is a component of a physical goal? Sticking to a nutrition plan Journaling about goals Joining a club Studying sports Which of the following best explains how introducing an invasive plant species to an ecosystem would affect the ecosystem over a long period of time? A) The plants would eventually form mutualistic relationships with native plant species. B) It would harm the ecosystem since the plants would compete with native plants for water, sunlight, and space. C) It would benefit the ecosystem since the plant species would serve as a food source for herbivores. D) The plants would crossbreed with native plant species and increase biodiversity in the ecosystem.