The surface area to volume ratio is a fundamental of biology. Its affects a variety of things, from the maximum size of a cell, to the shape of an organism, to how internal transport systems are arranged. The surface of a cell (membrane) is the site of exchange between its interior and external environment. This surface has to allow enough exchange to support what is inside of the cell. It is vital to know that as an object increases its volume increases. Therefore the surface area to volume ratio of a smaller object is larger than superior objects of similar shape. This affects the size of cells. o Explanation of the concept of surface area to volume ratio as it applies to cells and reaction rate.
The surface area of an object is the parts
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Because of how thin the leaves are no internal cell is too far from the surface to receive light. The epidermis is transparent, allowing sun to breach through the photosynthetic cells. o Description of the role of teeth in increasing the surface area of complex foods for exposure to digestive chemicals.
There are two stages during the digestion of foods. The first is the mechanical or physical breakdown. This is when the foods are chewed and turned into smaller pieces. The second stage is the chemical breakdown, where the digestive enzymes chemically break down large molecules to simple molecules. If the food has a large surface area to volume ratio the digestive enzymes function more efficiently. When large chunks of food are broken down by the teeth, they expose a larger surface area which the chemicals can act on. The volume of the food is still the same as before but the surface area to volume ratio is overall increased just by the action of chewing. This increases the rate of reaction with the digestive
Now the Cheetos have entered the stomach. The process of breaking down carbohydrates has already begun in the mouth and now more chemical and mechanical digestion will take place in the stomach. Once the bolus has entered the stomach, it mixes with gastric juice, starts protein digestion, and absorbs a limited amount. Here the chief cells secrete the inactive enzyme pepsinogen and the parietal calls secrete hydrochloric acid. When mixed together, they create pepsin. The pepsin works to breakdown the two grams of protein present in the Cheetos. Hormones are also present in the stomach and aid in the digestion process. The hormone, gastrin, increases the secretory activity of gastric glands. In the stomach, some salt from the Cheetos is absorbed through the wall. The Cheetos that entered the stomach has no...
Absorption is the way of digesting the food molecules into the small intestine. This process of absorption pass throughout the wall of the small intestine into the bloodstream. The bloodstream carried out all important nutrients to the
Surface area (of a solid). 4. A catalyst. 5. Pressure.
...on dioxide, within the body, affecting the pH balance of the blood. This will then affect proteins within the body, being known as enzymes, which can only function if their surrounding environment is in balance. Any alteration to this environment, will prevent the enzymes from functioning effectively.
In order for this breakdown to happen, the ‘tube’ through which the food travels requires assistance from a number of other digestive organs starting with the salivary glands, and later receiving
Digestion is defined as the process of transforming foods into unites for absorption. The Digestive System is a complex network of organisms that have six major processes: The digestion of food, the secretion of fluids and digestive enzymes, the mixing and movement of food and waste throughout the body, the digestion of food into smaller pieces, the absorption of nutrients, and the excretion of wastes (Inner Body (1).)
Imagine you are eating a sandwich containing wheat bread, ham, lettuce, and Swiss cheese. Do you ever wonder where the nutrients go from all of the previous listed ingredients? Well, when a bite of this sandwich is taken, the mouth produces a saliva enzyme called amylase. This enzyme immediately goes to work by breaking down the carbohydrates that are in the bread. Once, the bite is completely chewed, the contents then are swallowed and go down the esophagus and begin to head towards the upper esophageal sphincter and the is involuntarily pushed towards the stomach. The next passage for the sandwich is to go through the lower esophageal sphincter; which transports the sandwich into the stomach.
Regardless of the type of organism involved, the surface of the gas exchange system
material things have "this or that shape" and are small or large in relation to
π is equal to the osmotic pressure, V is equal to the cell volume and B is the intracellular solids (Hall). Ponder’s R value is the ratio of intracellular solvent volume to the water in its environment; R=(Vi -b)/W. These two equations are related because Ponder’s R value is a measure of how much of an osmometer a cell is while the van’t Hoff relation shows what the osmotic pressure is, both inside and outside the cell. Overall cell membrane permeability can be measured by Ponder’s R value while the osmotic pressure differentials between the external environment and the internal environment are seen with the van’t Hoff relation (Hall). Cells evolved to become great osmometers, but not perfect osmometers, in order to provide a way for solutes to move along permeable membranes. The van’t Hoff relation permits organisms to live in environments of varying osmolarity because regulating solute concentration within a cell can increase or decrease the cell’s affinity for osmosis (Darnell et al). Ponder’s R value, on the other hand, shows how a cell can never become a perfect osmometer. If a cell could become a perfect osmometer, it could cause cell lysis or shrinkage of the cell (Hall). The avoidance of perfect osmometry can be seen within the human erythrocyte as a small portion of cell water will not take part in an osmotic exchange due to tonicity within its
The relation of the three points above can be summed up by Fick’s Law: However, the amount of gas which an organism needs to exchange is greatly proportional to its volume, nevertheless, the amount of gaseous exchange which takes place is proportional to the surface area over which the exchange happens. For single celled/unicellular organisms the surface area to volume ratio is large, however, for larger organisms the surface area to volume ratio decreases. The larger the object gets the more complicated it gets.
a – side length Surface area of cube (SA) = 6a2 square units. a – side length Cylinder: cylinder The volume of the cylinder (v) = x r2 x h cubic unit. r – Radius of cylinder.
Dimensional analysis is routinely used to check the plausibility of derived equations and computations. It is also used to form reasonable hypotheses about complex physical situations that can be tested by experiment or by more developed theories of the phenomena, and to categorize types of physical quantities and units based on their relations to or dependence on other units, or their dimensions if any. In physics and all science, dimensional analysis is the practice of checking relations among physical quantities by identifying their dimensions. The dimension of any physical quantity is the combination of the basic physical dimensions that compose it. Some fundamental physical dimensions are length, mass, time, and electric charge. All other physical quantities can be expressed in terms of these fundamental physical dimensions. Detailed discussion of the dimensional analysis is depicted in the chapter on dimensional analysis.
The rate of reaction is how quickly or slowly reactants in chemical reactants turn into products. A low reaction rate is when the reaction takes a long time to take place; hence, a reaction that occurs quickly has a high reaction rate. A rate refers to how slow or quick the product is produced. It is possible to control the rate of chemical reactions and speed up or slow down the rate of chemical reactions by altering three main factors which are temperature, concentration and the surface area. When the temperature of the reactants increases, the molecules vibrate at a more intense speed therefore colliding with each other more frequently and with increased energy resulting in a greater rate of reaction. Accordingly, as the temperature decreases the molecules will move slower, colliding less frequently and with decreased energy resulting in the rate of reaction decreasing. Concentration is how much solute is dissolved into a solution and is also a factor that affects the rate of reaction. When the concentration is greater this means there is an increased amount of reactant atoms and molecules resulting in a higher chance that collisions between molecules will occur. A higher collision rate means a higher reaction rate. Consequently at lower concentrations there are reduced chances of the molecules colliding resulting in a lower reaction rate. The measurement of how much an area of a solid is exposed is called the surface area. The quicker a reaction will occur the more finely divided the solid is. For example, a powdered solid will usually have a greater rate of reaction in comparison to a solid lump that contains the same mass for it has a lower surface area than the powdered solid.