Acids, bases and salt
An acid is a substance that can donate a hydrogen ion (which can effectively be referred to as a proton, as when hydrogen loses its only electron, it only has a proton left). They have a pH of less than 7. There are two types if acids:
Weak acid – usually an organic compound with a small amount of dissociated molecules.
Strong acid - usually an inorganic compound with a large amount of dissociated molecules.
Hydrochloric acid is produced in the stomach from chorine and hydrogen. Carbonic acid is produced red blood cells from carbon dioxide and water. Hence any demanding exercise will lead to an increase in the acidity of the blood.
The control of osmosis
Salts are a major constituent of blood and the levels both inside/outside a cell can be controlled via ATP-energised pumps.
Sodium salts and chloride ions are pumped back out of a cell ever time they enter a cell. Whereas potassium salts are pumped back into cells as they leave a cell. The movement of salts enable us to assist osmosis through the cell membrane.
Roles of electrolytes
These are compounds that dissociate into ions when they are dissolved in water, causing them to become electrically charged particles that have the ability to conduct electricity. They can become cations (positively charged) or anions (negatively charged). Some electrolytes are considered essential minerals, these can not be made in the body and are an essential part of health:
- The major components of bone and teeth are phosphorus and calcium. With calcium required for blood clotting and contraction of muscles as well.
- The major constituent of a cell is potassium.
- The components of amino acids and proteins, bone and tendon collagen formation, keratin in nail and hair is sulphur.
- Magnesium is found in bone and teeth, as well as being used in contraction of muscles and is also an activator for various enzymes.
- Chloride is required to produce hydrochloric acid in the stomach.
There are trace elements present in the body. These are essential minerals that are required in only small amounts and consist of iron, iodine, copper, zinc, manganese, cobalt, chromium, selenium, molybdenum, fluorine, tin silicon and vanadium.
Acid-base balance
PH
Ph measures the amount of Hydrogen ions present in a solution. pH scale ranges from the values 1 to 14. The number 7 in the scale is the natural point and any other numbers between 1 and 7.Therefore the lower the number it would mean that there is a high acid .
Importance of maintaining the hydrogen ion concentration in body fluid
Buffer systems are in place in order to maintain and stabilise the pH of cellular/body fluids. Metabolic activities are controlled by enzymes, which can be described as organic catalysts.
Solvent and surface tension
For many substances in the body water is an excellent solvent. Water has a high surface tension; which is evident when it comes into contact with air.
Solutes
The cell membrane is a partial permeable barrier that allows only certain molecules through the bilayer, therefore some material due get passed due to the cell evaluation.
There are two ways for the energy to get out, that are kinetic and potential. When the water molecules move according to the disparity, this where the energy is found from where to begins to where it ends. The water cycle is worked through the gravity (hydrological).
- Materials can be transported between the cytoplasm and the outside cell environment by different process, some of which may require energy in the form of ATP. Active transport can be used in order to get the molecules to go against the concentration gradient, exchange to be faster etc. it can be facilitated diffusion or osmosis.
- The phospholipids molecule has both a hydrophobic and hydrophilic nature, therefore a bilayer can form creating a barrier for cell membranes, with the lipid molecules in the middle restricting certain molecules through.
- Fluid mosaic model shows the structure of the phospholipids membrane with all other compounds that are included in it i.e. carrier proteins, glycoprotein, cholesterol etc.
- Molecules have a tendency to move from an area of high concentration to an area of low concentration down a concentration gradient. Molecules are always moving around, when they balance out the concentration gradient the molecule do not stop moving, they keep moving but there is no net movement, therefore they reach a stage of equilibrium.
Role of water in relation to properties
*Specific heat capacity: the specific heat capacity is where the quantity of the energy needs to increae1kg of a substance by 1ºk in the Kevin scale which is the SI scale temperature. There are high heat capacities in water that need a lot of energy to increase 1kg of water to one degree of temperature.
Basically this means in hot weathers the humans will not have a major increase in temperature and will not even cool down as quick
There is high heat of vaporisation in water which also takes a lot of energy to convert the liquids in to water vapour. This means that when sweat is produced and is vanishing from the skin, due to the energy being used in so doing it helps the skin cool down.
*Surface tension: there is high surface tension in water as the amount of water present with the air or other materials have a small area. Watery film that are in-between the two pleural surface where one in the lining of the inside chest wall and the other covering the lung builds tension making the lung to pull the surface along when the ribs are moving up and down during the inspiration.
Distribution of water
Average person’s weight in physiology is calculated at 70kg and 60% of the weight is water. The overall water in the body involves water inside the cells which is recognised as intracellular which is about 28 litres and the extracellular water which is out the cells that is about 14 litres.
The tissue fluid which is known as the intercellular and the interstitial fluid have the majority component f the extracellular fluid as it has 11 litres compared to the 3 litre of plasma. The lymph has 10% of the tissue fluid that form in the remainders of the plasma.
Role of tissue fluid in homeostasis
In the homeostasis the tissue fluid has vital role as the fluid is pushed out of the arterial end of the capillary by the blood pressure then has remain after the bloods been pushed out through the muscular arterioles and capillaries. During this stage there are low carbon dioxide and high dissolved oxygen concentration as well as being filled up with other nutrients like amino acid, salt and glucose. The tissue fluid flows around the cells and in between giving out the raw materials by osmosis, facilitated diffusion and diffusion etc. The waste metabolic material gets passed in the opposite direction to the cells and then into the tissue fluid. Therefore if allowed to accumulate, this would or can cause disruption that can lead to the cells dying and then death can occur.
Sources used
BTEC health and social care book 1 (from unit 13 section)
OCR Biology A2 book (from unit 1)