aterials in the Body - fluid balance assigment
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sophiegarraolcom (student)
Task 2
States of matter
Matter is material that has substance and occupies space. There are three different types of matter these are, Solid, Liquid, Gas, and Solid matter
Bone, cartilage and skin are materials that are solids this is because the atoms/molecules are packed tightly together that the motion is reduced to a very tiny vibration.
Liquid matter
Blood, tissue fluid, lymph and urine are all liquid this is because they can flow, the atoms/molecules are further apart then in a solid and so the atoms have more movement, resulting in flowing. Liquids take shape from their container whether this is a vessel such as in blood and lymph.
Gases
Gases also occur in the human body, oxygen, carbon dioxide and nitrogen are common constituents of the air that we breathe in. The atoms/molecules are much further apart from each other and are able to move about a lot more freely.
http://www.astarmathsandphysics.com/o_level_physics_notes/fg0-7645-5430-1_0201.jpg
this picture shows the different molecules for solid, liquids and gases. http://www.astarmathsandphysics.com/o_level_physics_notes/o_level_physics_notes_solids_liquids_and_gases.html
Materials
Particulate material
Particles such as dust from coal can reach even the tiniest air passages, causing scarring and disease. Such particles are very fine, particulate material can enter any open wound and rest in deeper tissues, where the macrophages will attempt to engulf and digest the partials. Bacteria digested by lysosomes will leave some debris behind such as particulate matter for example a person lungs who smoke or work in a dusty environment resulting in blackened tissues resulting from particulate matter.
Ionic material
This is material containing atoms that may have a positive or negative charge as a result of gaining or losing electrons. Ionic material is designated by the relevant charge shown against the atom.
In solution
Substances that are capable of dissolving in a liquid are called solutes; the liquid is the solvent and the solute dissolved in the solvent is a solution. Water is the most common molecule in the human body and most chemical reactions involve molecules dissolved into water.
Relevant colloidal forms
A colloid consists of larger particles, which are dispersed or scattered throughout a medium gas, liquid or solid.
Protein sols
Cytoplasm is an example of a colloid caused by the protein molecules that are not readily dissolved on water, so it is a protein sol. Blood plasma is another protein sol because of its plasma protein content. Polysaccharide molecule can also produce colloids when mixed with water. They are not readily soluble, as the molecules like proteins as they can be too large to dissolve.
Emulsions
An emulsion occurs when one liquid is dispersed in droplets in another, such as fat in milk. Emulsifying agents cause one liquid to form very small droplets which increases the surface area. This is what happens when bile salts are added to fats in chime in the small intestine, the fats brake up into thousands of tiny globules, producing a milky appearance.
Movement of materials
Diffusion
When there is a large number of molecules of a substance and a small number in another area with no effective barrier between them, this random motion ...
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Emulsions
An emulsion occurs when one liquid is dispersed in droplets in another, such as fat in milk. Emulsifying agents cause one liquid to form very small droplets which increases the surface area. This is what happens when bile salts are added to fats in chime in the small intestine, the fats brake up into thousands of tiny globules, producing a milky appearance.
Movement of materials
Diffusion
When there is a large number of molecules of a substance and a small number in another area with no effective barrier between them, this random motion will cause the numbers to even up. This is known as diffusion. Diffusion is the movement of molecules from a region of high concentration to a region of high concentration to low concentration.
In the body diffusion often takes place through the cell membranes, but these are freely passable to the diffusing molecules provided that the barrier is thin. In the lungs there are only two simple squamous epithelial cells separating the dissolved gases in the alveoli from the blood in the pulmonary capillaries. There is no source of energy required for diffusion of molecules.
http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20101/bio%20101%20lectures/membranes/diffusion.png
Facilitated diffusion
Some materials diffuse through the cell membrane by a related process known as facilitated diffusion. To facilitate something it means to make it easier and the protein channels in the cell membrane assist in transporting molecules such as glucose and urea into and out of the cell. The channel proteins have a shape to prevent further molecules binding until it is released on the opposite side of the membrane.
In the body facilitated diffusion happens with glucose transport. Glucose is the body’s primary source of direct energy. Our cells have a membrane protein that facilitates the diffusion of glucose from the bloodstream into the cell.
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Osmosis
Osmosis is a special type of diffusion of water molecules. It is the movement of water molecule from a region oh high concentration to low concentration through a selective permeable membrane. In addition, there is a selectively permeable membrane. You can think of permeable as leaky; a freely permeable membrane will allow most small molecules to pass through. A selective permeable membrane allows some molecules through but not others these molecules are normally too big. Pressure could be supplied to the of the protein solution to prevent water molecules passing through the selectively permeable membrane from the water limb. This is known as the osmotic pressure of the protein solution.
In the body osmosis occurs in the distal convoluted tubules of the kidney naphrons as they pass through a region of high sodium concentration in order to concentrate urine.
Active transport
Active transport is the process by which dissolved molecules move across a cell membrane from a lower to a higher concentration. In active transport particles move against the concentration gradient- and therefore require an input of energy from the cell.
In the human body active transport takes place during the digestion of food in the small intestine. Carbohydrates are broken down into simple sugars such as glucose. The glucose is absorbed by active transport into the villi, to be passed into the bloodstream and taken around the body.
Exoctosis and Endocytosis,
The movement of macromolecules such as proteins or polysaccharides into or out of the cell this is called bulk transport. There are two types of bulk transport these are called exocytosis and exocytosis and they both require energy (ATP).
In exocytosis, materials are exported out of the cell via secretory vesicles. In this process, the Golgi complex packages macromolecules into transport vesicles that travel to and fuse with the plasma membrane. This fusion causes the vesicle to spill its contents out of the cell. Exocytosis is important in expulsion of waste materials out of the cell and in the secretion of cellular products such as digestive enzymes or hormones.
http://www.wyzant.com/Images/Help/Biology_Exocytosis_2.jpg
Endocytosis, on the other hand, is the process by which materials move into the cell. There are three types of endocytosis:phagocytosis, pinocytosis, and receptor-mediated endocytosis. In phagocytosis or “cellular eating,” the cell’s plasma membrane surrounds a macromolecule or even an entire cell from the extracellular environment and buds off to form a food vacuole or phagosome. The newly-formed phagosome then fuses with a lysosome whose hydrolytic enzymes digest the “food” inside.
http://www.wyzant.com/Images/Help/Biology_Phagocytosis_2.jpg
In pinocytosis or “cellular drinking,” the cell engulfs drops of fluid by pinching in and forming vesicles that are smaller than the phagosomes formed in phagocytosis. Like phagocytosis, pinocytosis is a non-specific process in which the cell takes in whatever solutes that are dissolved in the liquid it envelops.
http://www.wyzant.com/Images/Help/Biology_Pinocytosis_2.jpg
Unlike phagocytosis and pinocytosis, receptor-mediated endocytosis is an extremely selective process of importing materials into the cell. This specificity is mediated by receptor proteins located on depressed areas of the cell membrane called coated pits. The cytosolic surface of coated pits is covered by coat proteins. In receptor-mediated endocytosis, the cell will only take in an extracellular molecule if it binds to its specific receptor protein on the cell’s surface. Once bound, the coated pit on which the bound receptor protein is located then invaginates, or pinches in, to form a coated vesicle. Similar to the digestive process in non-specific phagocytosis, this coated vesicle then fuses with a lysosome to digest the engulfed material and release it into the cytosol. Mammalian cells use receptor-mediated endocytosis to take cholesterol into cells. Cholesterol in the blood is usually found in lipid-protein complexes called low-density lipoproteins (LDLs). LDLs bind to specific receptor proteins on the cell surface, thereby triggering their uptake by receptor-mediated endocytosis.
http://www.wyzant.com/Images/Help/Biology_Endocytosis_2.jpg
In the human body examples for endocytosis is the leucocytes, neutrophils, and monocytes can engulf foreign substances like bacteria , examples for exocytosis is secretion of enzymes from pancreatic cells and hormones from endocrine glands
Task 2 M2 - Explain the factors that influence the movement of materials into and out of cells
Size
The size of any surface for transport is vital, as it must be large enough to allow sufficient molecules or ions to be transported to accommodate the metabolic processes in a cell. This is why the surface area to volume ration has to be critical. Everything the cell needs or has to get rid of has to go through the cell membrane. The amount of cell membrane limits the ability of cells to either get substances from the outside or transport waste and other materials to the outside. This ability is related to surface area. The relationship between surface area and volume controls cell size. As a cell gets larger, its volume increases faster than its surface area if the cell maintains the same shape.
Surface Area and Volumes of Cubes
Number of Cubes
Side Length
Surface Area
Volume
Cubes
1
4 cm
96 cm2
64 cm3
Cubes
8
2 cm
192 cm2
64 cm3
Cubes
64
1 cm
384 cm2
64 cm3
Look at the chart above. Notice that the volumes are all the same, but the surface area changes. As the cell gets bigger, there comes a time when its surface area is not large enough to allow resources to travel to all parts of the cell, so the cell stops growing. A cell's shape also affects its surface area. For example, some single- celled organisms are thin and flat, providing increased surface area. Other cells, such as nerve cells and muscle cells are long and skinny, which also gives them a higher ratio of surface area to volume. A cell's shape also affects its surface area. For example, some single- celled organisms are thin and flat, providing increased surface area. Other cells, such as nerve cells and muscle cells are long and skinny, which also gives them a higher ratio of surface area to volume.
Distance
Any situation that means the molecule has to travel further reduces the efficiency of the transport process, for example the extra fluid and mucus in the alveoli caused by pneumonia. Diffusion works quickly over a short distance but is much less effective over a long distance.
Temperature
The higher the temperature means more kinetic energy this means that the molecules will move faster. The rate of transport will increase in diffusion and osmosis this is because the rate of transport will increase up to the point in the other transport systems but then will decrease this happens due to other transport systems requires the membrane proteins which will become more denatured at higher temperatures.
Osmotic potential
Similar to concentration gradient osmotic potential needs water to move from areas of high concentration to areas of low concentration, the more diluted solution has to have a higher osmotic potential. Water has the highest osmotic potential for example an aqueous tissue fluid returning to protein rich blood.
Electrochemical gradient
The exterior of the cell membranes carries a positive charge the interior of the cell membrane carries a negative charge. This means that negatively charged molecules and ions such as chloride ions have a tendency to be pushed out of the cell on the other hand positively charged molecules and ions such as sodium and potassium have a tendency to be attracted into the cell. The difference in charge between the inside and outside of the membrane is sometimes called the membrane potential.
Permeability of cell membrane
Molecules and ions with a charge diffuse across the phospholipid bilayer very slowly or not at all, non-charged molecules diffuse quite rapidly as they can dissolve in the fatty acid chain part of the bilayer. Oxygen, carbon dioxide and steroids can move across easily in this way. The fatty avid chain part of the bilayer therefore acts like a selective barrier for cretin things to enter.
Channel proteins
Channel proteins are almost impermeable to charged ions we know this because over time scientist has been doing experiments using artificial bilayer with no channel proteins have shown it to be almost impermeable to charged ions. Real membranes however are permeable to these ions this proves channel proteins are essential in the transport of charged ions; these proteins are specific to the ions they transport.
http://uk.ask.com/question/how-does-the-cell-size-affect-the-transport-of-materials-into-the-cell
http://www.wyzant.com/resources/lessons/science/biology/endocytosis-and-exocytosis
by
sophiegarraolcom (student)
