Enzymatic digestion is responsible for breaking organic material into smaller subunits that can be absorbed into the circulatory system.

The amount of enzymatic digestion within the oral cavity is small in comparison to the activity of the lower GI tract. However, there is some initial digestion of both carbohydrates and lipids in the oral cavity.

The salivary glands, primarily the submandibular and sublingual glands, secrete an enzyme called salivary amylase.

Recall that the nutrients are primarily absorbed from the digestive system in their simplest structure, or monomers. Salivary amylase belongs to a class of enzymes that digest complex carbohydrates, such as starch, into monosaccharides.

The monosaccharides are easily absorbed into the circulatory system, although little absorption occurs in the oral cavity. The salivary amylase is mixed into the food by the action of the tongue and cheeks and continues to break down the starches in the food for about an hour until deactivated by the acidic pH of the stomach. A second enzyme of the oral cavity is lingual lipase.

Lingual lipase is secreted from glands on the surface of the tongue. This enzyme acts on triglycerides in the food, breaking them down into monoglycerides and fatty acids. How ever, the action of this enzyme is relatively minor and it does not make a major contribution to overall lipid digestion.



Physics is the study of dynamics. Dynamics is the description of the actual forces of nature that, we believe, underlie the causal structure of the Universe and are responsible for its evolution in time. We are about to embark upon the intensive study of a simple description of nature that introduces the concept of a force, due to Isaac Newton. A force is considered to be the causal agent that produces the effect of acceleration in any massive object, altering its dynamic state of motion.

Newton was not the first person to attempt to describe the underlying nature of causal ity. Many, many others, including my favorite ‘dumb philosopher’, Aristotle, had attempted this. The major difference between Newton’s attempt and previous ones is that Newton did not frame his as a philosophical postulate per se. Instead he formulated it as a mathemat ical theory and proposed a set of laws that (he hoped) precisely described the regularities of motion in nature.

In physics a law is the equivalent of a postulated axiom in mathematics. That is, a physical law is, like an axiom, an assumption about how nature operates that not formally provable by any means, including experience, within the theory. A physical law is thus not considered “correct” – rather we ascribe to it a “degree of belief” based on how well and consistently it describes nature in experiments designed to verify and falsify its correspon dence.

It is important to do both. Again, interested students are are encouraged to look up Karl Popper’s “Falsifiability 29 and the older Postivism30. A hypothesis must successfully withstand the test of repeated, reproducible experiments that both seek to disprove it and to verify that it has predictive value in order to survive and become plausible. And even then, it could be wrong!

If a set of laws survive all the experimental tests we can think up and subject it to,

we consider it likely that it is a good approximation to the true laws of nature; if it passes many tests but then fails others (often failing consistently at some length or time scale) then we may continue to call the postulates laws (applicable within the appropriate milieu) but recognize that they are only approximately true and that they are superceded by some more fundamental laws that are closer (at least) to being the “true laws of nature”.

Newton’s Laws, as it happens, are in this latter category – early postulates of physics that worked remarkably well up to a point (in a certain “classical” regime) and then failed. They are “exact” (for all practical purposes) for massive, large objects moving slowly com pared to the speed of light3³1 for long times such as those we encounter in the everyday world of human experience (as described by Sl scale units). They fail badly (as a basis for prediction) for microscopic phenomena involving short distances, small times and masses, for very strong forces, and for the laboratory description of phenomena occurring at rela tivistic velocities. Nevertheless, even here they survive in a distorted but still recognizable form, and the constructs they introduce to help us study dynamics still survive.

Interestingly, Newton’s laws lead us to second order differential equations, and even quantum mechanics appears to be based on differential equations of second order or less. Third order and higher systems of differential equations seem to have potential problems with temporal causality (where effects always follow, or are at worst simultaneous with, their causes in time); it is part of the genius of Newton’s description that it precisely and sufficiently allows for a full description of causal phenomena, even where the details of that causality turn out to be incorrect.

Incidentally, one of the other interesting features of Newton’s Laws is that Newton in vented calculus to enable him to solve the problems they described. Now you know why calculus is so essential to physics: physics was the original motivation behind the invention of calculus itself. Calculus was also (more or less simultaneously) invented in the more useful and recognizable form that we still use today by other mathematical-philosophers such as Leibnitz, and further developed by many, many people such as Gauss, Poincare, Poisson, Laplace and others.

In the overwhelming majority of cases, especially in the early days, solving one or more problems in the physics that was still being invented was the motivation behind the most significant developments in calculus and differential equa tion theory. This trend continues today, with physics providing an underlying structure and motivation for the development of much of the most advanced mathematics.



by – penserstudypoint.com

Life on the earth, as we all know that depends on the liquid tamperature that dominates the earth’s surface.

Most life on the world needs average temperatures between the freezing and boiling points of water.

The earth’s orbit is that the right distance from the sun to produce these conditions. If the world were a lot of nearer to the sun, it’d be too hot-like Venus—for vapour to condense and type rain.

If it were a lot of farther away, the layer would be thus cold-like Mars—that its water would exist solely as ice. The world conjointly spins, if it didn’t, the aspect facing the sun would be too hot and therefore the different aspect too cold for water-based life to exist.

The size of the world is additionally excellent always. It’s enough mass to stay its iron and nickel core liquefied and to stay the atmosphere—made of light-weight aerosolized molecules needed always (such as N2, 02, CO2, and H,0)-from flying off into house.

Although life on earth has been enormously resilient and reconciling, it’s profit tough guy from a positive temperature vary. Throughout the 3.7 billion years since life arose, the common surface temperature of the world has remained among the slender vary of 10-20 °C (50–68 °F), even with a 30-40% increase within the sun’s energy output.

One reason for this can be the evolution of organisms that modify levels of the temperature-regulating gas carbonic acid gas within the atmosphere as a vicinity of the carbon cycle.

For almost 600 million years, gas has created up concerning twenty first of the degree of earth’s atmosphere. If this gas content born to concerning V-J Day, it’d be deadly for many varieties of life. If it exaggerated to concerning twenty fifth, gas within the atmosphere would in all probability ignite into a large fireball.

This gas content of the atmosphere is essentially the results of producer and client organisms interacting within the carbon cycle. Also, as a result of the event of photosynthesizing microorganism that are adding gas to the atmosphere for quite two billion years, ozone gas within the layer protects us and plenty of different varieties of life from an over dose of UV.



This image has an empty alt attribute; its file name is ngc-2818-11126_1920.jpg


Nebula, a type of cloud in space.
It is formed by dust particle and gases that present in space. When a star die, it will exploded and spread dust and gases all over in space and when a star start its formation the best gas all around it and make a nebula.

The gas in nebulae is mostly hydrogen and helium.

The spreaded gas and dust start to collect condense and make stars.

Nabulae can be anywhere in space near the stars. Hellix nebula is the nearest nebula to us.

This image has an empty alt attribute; its file name is helix-nebula-11156_1920.jpg

Some nebulae are very large such as approximate diameter of 100 light years.

Nebulae are visible in space but not brighter as stars.

There are different types of nebulae and named on the basis if their shapes such as Skull nebula, Cat nebula, Red Rectangle nebula, etc.

Most of the nebulae have no boundries and these nebulae are called diffuse nebula.

Due to very low in density, nebulae have very low mass. Even an earth size nebula have mass of few kilograms.



Eclipses are among the most spectacular astronomical events you can see. They occur when the Earth, Moon, and Sun all line up so that the Earth casts a shadow on the Moon or the Moon casts a shadow on the Earth. The Sun or Moon appear to go dark to people standing inside these shadows.


The Moon passes between the Sun and Earth every month at “new Moon,” but because its orbit is slightly tilted it usually does not pass directly in front of the Sun. Occasionally, however, it does move directly in front of the Sun and causes a solar eclipse. Although the Sun is 400 times wider than the Moon, by a curious coincidence it is also 400 times farther away. As a result, when viewed from Earth the Moon’s disk fits exactly over the Sun’s disk during a total solar eclipse.

Shadow play
A total solar eclipse can be seen only from the center of the Moon’s shadow—the umbra. The umbra sweeps across Earth during an eclipse, tracing a path thousands of miles long but no more than 60 miles (100 km) wide. Outside the umbra, the Moon casts a partial shadow causing a partial solar eclipse

Two or three times a year, the Moon passes through Earth’s enormous shadow and a lunar eclipse occurs. Surprisingly, the Moon does not become completely black. Some sunlight is refracted (bent) by Earth’s atmosphere and makes the Moon turn orange-red, like a red sunset. Lunar eclipses are easier and much safer to see than solar eclipses, since anybody with a view of the Moon can see them.

When day becomes night
A total solar eclipse occurs about every 18 months. If you are in the right place to see one, it is an amazing experience. As the last rays of sunlight are eclipsed, darkness falls, stars appear, and day turns to twilight. All that can be seen of the Sun is its hazy outer atmosphere.



Food webs

Energy passes from one animate thing to a different within the sort of food. Food webs show however living things go after each other. At very cheap of a food cycle are plants, that build their own food, taking energy from the Sun. At the highest ar predators, that go after alternative animals.

Food chain
Food webs are created from totally different, many various, many alternative food chains that have different levels. In a very organic phenomenon, plants are referred to as producers as a result of they create their own food. Animals that eat plants are referred to as primary customers. Primary customers are ingested by alternative animals referred to as secondary customers, or predators. Once all living things die they become the food of organisms referred to as decomposers.

Food pyramid
As we have a tendency to go up a organic phenomenon, the number of food offered decreases. This is often as a result of living things use most of the energy within the food they eat respiration. A organic phenomenon shows however energy is lost at every level. close to the highest, there ar simply many predators, whereas at very cheap there are more producers.



Photo by meo on Pexels.com

1:-You have a finite amount of willpower each day because to exercise your willpower you need energy in the form of oxygen and glucose. That’s why it’s harder to say ‘no’ when you are tired or not feeling yourself.

2:-A thought is a physical pathway in the brain. The more you have that thought, the more you groove and strengthen that path and the easier it is to have it again and again.

3:-Even if you consider yourself a creative right brained person, your brain will increase blood circulation to the left of your brain side every 90 to 120 minutes, giving you a greater ability during those times to think linearly.

4:-Your brain only weighs about 3lbs, yet the greedy bastard uses between 20% and 25% of your energy supplies each day, so make sure you stay hydrated and eat high quality food.

5:-Speaking of large numbers, there are approximately 1.1 trillion cells and 100 billion neurons in the average human brain.

6:-A piece of brain tissue the size of a grain of sand contains approximately 100,000 neurons and 1 billion synapses.


Hydrophobic interactions

Some molecules just don’t play nicely with water. Because water is a polar molecule, it tends to stick to itself via hydrogen bonds. Other polar molecules also stick to water molecules and can mix right in, dissolv ing into the water. However, nonpolar molecules have evenly shared covalent bonds and lack the slight negative and positive charges of polar molecules. Because they’re uncharged, nonpolar molecules don’t mix well with water.

Nonpolar molecules are also called hydrophobic molecules because “hydro” means water and “phobic” means to fear.

When nonpolar molecules are placed in a watery environment, the polar mol ecules will all stick to each other and push the nonpolar molecules away. You can think of the scenario as if the polar molecules all belong to a clique that refuses to hang out with the nonpolar molecules. (The name of this clique, by the way, is the hydrophilic molecules.) Because the nonpolar molecules all get pushed together, they become associated with each other.

The interaction between nonpolar molecules is called a hydrophobic interaction.

You can easily demonstrate a hydrophobic interaction to yourself. Just go into your kitchen, put some water in a cup, and then add a little oil. Even if you stir the mixture vigorously to mix the oil into the water, as soon as you stop stirring, all the oil will gather together on top of the water.

The water molecules all stick to each other and push the oil molecules away. Hence the saying, “They get along like oil and water!”


The Bending of Light in a Gravitational Field

Let us consider a ray of light that shines through a window in an elevator at rest, as shown in figure. The ray of light follows a straight line path and hits the opposite wall of the elevator at the point P.

Let us now repeat the experiment, but let the elevator accelerate upward very rapidly, as shown in figure. The ray of light enters the window as before, but before it can cross the room to the opposite wall the elevator is displaced upward because of the acceleration. Instead of the ray of light hitting the wall at the point P, it hits at some lower point Q because of the upward acceleration of the elevator.

To an observer in the elevator, the ray of light follows the parabolic path, as shown in figure. Thus, in the accelerated coordinate system of the elevator, light does not travel in a straight line, but instead follows a curved path. But by the principle of equivalence the accelerated elevator can be replaced by a gravitational field. Therefore light should be bent from a straight line path in the presence of a gravitational field.

The gravitational field of the earth is relatively small and the bending cannot be measured on earth. However, the gravitational field of the sun is much larger and Einstein predicted in 1916 that rays of light that pass close to the sun should be bent by the gravitational field of the sun.

Another way of considering this bending of light is to say that light has energy and energy can be equated to mass, thus the light-mass should be attracted to the sun. Finally, we can think of this bending of light in terms of the curvature of spacetime caused by the mass of the sun. Light follows the shortest path, called a geodesic, and is thus bent by the curvature of spacetime.

Regardless of which conceptual picture we pick, Einstein predicted that a ray of light should be deflected by the sun by the angle of 1.75 seconds of arc. In order to observe this deflection it was necessary to measure the angular deviation between two stars when they are far removed from the sun, and then measure the deflection again when they are close to the sun. Of course when they are close to the sun, there is too much light from the sun to be able to see the stars.

Hence, to test out Einstein’s prediction it was necessary to measure the separation during a total eclipse of the sun. Sir Arthur Eddington led an expedition to the west coast of Africa for the solar eclipse of May 29, 1919, and measured the deflection. On November 6, 1919, the confirmation of Einstein’s prediction of the bending of light was announced to the world.

More modern techniques used today measure radio waves from the two quasars, 3c273 and 3c279 in the constellation of Virgo.

A quasar is a quasi-stellar object, a star that emits very large quantities of radio waves. Because the sun is very dim in the emission of radio waves, radio astronomers do not have to wait for an eclipse to measure the angular separation but can measure it at any time.

On October 8, 1972, when the quasars were close to the sun, radio astronomers measured the angular separation between 3c273 and 3c279 in radio waves and found that the change in the angular separation caused by the bending of the radio waves around the sun was 1.73 seconds of arc, in agreement with the general theory of relativity.




Water, which scientists estimate comprises approximately 60 to 75 percent of the human body, is important for three primary reasons: it acts as a solvent, it acts as a lubricant, and because it changes temperature slowly, it is vital in regulating the body’s temperature. The first reason because it is a solvent-means that many substances can dissolve in it, which allows nutrients and other vital components to be transported throughout the body. This is because the body’s main transportation systems, blood, are largely composed of water.

Therefore, substances like glucose (which comes from food) that are needed for energy in the body can be dissolved in the blood and then delivered to the heart and cells. Another important function is the elimination of waste. Materials that the body does not need, called waste products, are dissolved in the water component of urine and then flushed out of the body through the urinary system.

In addition to acting as a solvent, water is a lubricant, which means it prevents friction between the various surfaces inside the body, such as bones and blood vessels. One example of water acting as a lubricant is in the diges tive system. One of the fluids present in this system is the fluid mucus, which, like blood, is primarily made up of water. Mucus enables food to move through the intestines and be digested, providing the body with fuel.

The third function of water in the body is that of a temperature regulator. The temperature of water does not change quickly-it has to absorb a lot of heat or lose a lot of heat before the temperature increases or drops. This property enables the body to stay at a fairly constant temperature. In addition, water does an important cooling job for the body in the form of perspiration. When the body is absorbing an excess amount of heat, sweat forms on the skin, which allows the heat to escape the body without damaging any cells.