Biophysics Dictionary (2024-2025) PDF

Biophysics Dictionary 1. Basic quantity is like the brick – the basic building block of a house. It does not depend on other quantity in its definition. 2. Derived quantity is like the house that was build up from a collection of bricks (basic quantity). It depends on other quantity in it...

Biophysics Dictionary 1. Basic quantity is like the brick – the basic building block of a house. It does not depend on other quantity in its definition. 2. Derived quantity is like the house that was build up from a collection of bricks (basic quantity). It depends on other quantity in its definition. 3. 1 nm=10-8Ӑ=10-9 m=10-10cm 4. 1 nm equal 10 times the diameter of hydrogen atom. 5. Density ( ) is defined as a mass (m) per unit volume (V) or ⁄. Or the mass of the unit volume from the substance. 6. One mole is the amount of a substance that consist of Avogadro's number (NA=6.02×1023 atoms/mole) of atoms or molecules of this substance. 7. Avogadro's number (NA=6.02×1023 atoms/mole) is the total number of the molecules in one mole from the substance. 8. The higher the erythrocyte sedimentation rate (ESR) the lower the viscosity of the blood. 9. The lower the erythrocyte sedimentation rate (ESR) the higher the viscosity of the blood. 10. Poise is the CGS unit of viscosity and in SI Unit equal to 0.1 Pa. s (0.1 N. s/m2). 11. Poise is the CGS unit of viscosity and in SI Unit equal to 1(dyne. s/cm2). 12. The normal range of the erythrocyte sedimentation rate (ESR) in male 0-20 mm/hr. 13. The normal range of the erythrocyte sedimentation rate (ESR) in females 0-30 mm/hr. 14. The ESR (the precipitation rate) is typically higher in females than in males and increased gradually with age. 15. Temperature: a measure of how hot or cold an object is compared to another object. 16. If two objects are in thermal contact and there is no energy exchange the objects are said to be in thermal equilibrium. 17. Heat is the total energy of the motion of the molecules of a substance. 18. The Heat Sources are chemical reactions, nuclear reactions, electricity and mechanical friction. 19. Heat Capacity: The amount of thermal energy required to raise the temperature of an object one degree. 20. Specific Heat: The amount of thermal energy required to raise the temperature of one gram of a substance one degree. 21. Latent Heat: The amount of thermal energy required to change the phase of one gram of a substance. 1 22. During the phase change the temperature is remains constant and the energy used to overcome the attractive forces between the molecules. 23. The amount of the higher-phase material will increase Δ m and Q are positive during fusion or vaporization processes. 24. The amount of the higher-phase material will decrease Δ m and Q are negative during freezing or condensation processes. 25. The latent heat of vaporization is used when the phase change is from liquid to gas. 26. The flow of heat by conduction in solids inversely proportional with the length. 27. The flow of heat by conduction in solids directly proportional with the surface area. 28. The flow of heat by conduction in solids directly proportional with the temperature difference through the material terminals. 29. The heat transfers by three methods, conduction in solid, convection in fluids and radiation by electromagnetic waves. 30. If the flow of the fluids is caused by differences in density due to thermal expansion this is the free convection. 31. If the fluid is circulated by a blower or pump, the process is called forced convection. 32. Radiation is the transfer of heat by electromagnetic waves such as visible light, infrared, and ultraviolet radiation. 33. An ideal absorber is defined as an object that absorbs all of the energy incidents on it. 34. when the gas is kept at a constant temperature, its pressure is inversely proportional to its volume (Boyle’s law). 35. when the pressure of the gas is kept constant, its volume is directly proportional to its temperature (the law of Charles and Gay–Lussac). 36. An ideal gas is one for which PV/nT is constant at all pressures. 37. Any changes to electric or magnetic fields causes electromagnetic waves to propagate away from the disturbance. 38. electromagnetic waves are made by vibrating electric charges and can travel through space by transferring energy between vibrating electric and magnetic fields. 39. Electromagnetic waves are light and do not need matter to transfer energy. 40. The electric and magnetic fields vibrate at right angles to the direction the wave travels so it is a transverse wave. 41. The wavelengths become shorter as the temperature of the material increases. 42. Light is a transverse wave of varying electric and magnetic fields. 2 43. EM waves usually travel slowest in solids and fastest in gases. 44. All EM waves travel 300,000 km/sec in space. 45. Wavelength = the distance between two successive points with the same phase in the wave. 46. Wavelength of a transverse wave = distance from bottom to bottom on the same wave. 47. Wavelength of a longitudinal wave = distance from compression to compression on the same wave. 48. Wavelength of a longitudinal wave = distance from stretched to stretched on the same wave. 49. Frequency= number of wavelengths that pass a given point in 1 s. 50. Frequency = The number of complete cycles in one second. 51. Period = The time required to make a full cycle, or full vibration. 52. Unit of frequency is Hertz. 53. Unit of Period is Second=Hertz-1 54. As frequency increases, wavelength becomes smaller. 55. The ones humans can see are called visible light, a small part of the whole spectrum. 56. Radio waves are lowest frequency and energy than microwaves. 57. Infrared radiations just below visible and are higher frequencies than microwaves. 58. Infrared radiation just below visible and are lower wavelengths than microwaves. 59. Infrared radiation has higher energy than radio waves. 60. Infrared radiation has lower energy than ultraviolet waves. 61. Infrared radiation has higher wavelength than ultraviolet waves. 62. Ultraviolet waves have higher energy than visible and infrared waves. 63. Ultraviolet waves have higher wavelengths than X-ray and Gamma Rays. 64. Gamma rays have the highest frequencies and energies then X-ray. 65. Waves with higher frequency have higher energy and lower wavelength. 66. Radio waves are low frequency EM waves with wavelengths longer than 1mm. 67. Cell phones and satellites use microwaves between 1 cm & 20 cm for communication. 68. MRI use radio waves to diagnose illnesses with a strong magnet and a radio wave emitter and a receiver. 69. Protons in H atoms of the body act like magnets lining up with the magnetic field in MRI. 70. Infrared EM waves with wavelengths between 1 mm to 700 nm. 71. Infrared EM waves used daily in remote controls, to read CD-ROMs. 72. Satellites can ID types of plants growing in a region with infrared detectors. 73. Near- IR. The wavelength ranges from 0.75 to 1.4 micrometers. 74. Near- IR. used in material science, fiber optic communication, and in the medical field. 75. Mid-IR. The wavelength ranges from 3 to 8 micrometers. 3 76. Mid-IR. used in the chemical industry and in astronomy. 77. Far-IR. The wavelength ranges from 15 to 1000 micrometers. 78. Far-IR. used mainly in the treatment of cancer therapy. 79. There are infrared saunas used to treat high blood pressure and rheumatoid arthritis. 80. Infrared radiation is considered to be one of the safest methods of physiotherapy. 81. Infrared rays are used for warming the skin and for relaxing the muscles. 82. Infrared rays are preferred because of their penetration quality through the skin. 83. Ultraviolet EM waves with wavelengths from about from 400 nm to 10 nm. 84. UV-C rays are the most harmful and are almost completely absorbed by our atmosphere. 85. UV-B rays are the harmful rays that cause sunburn. Exposure to UV-B rays increases the risk of DNA and other cellular damage in living organisms. 86. Fortunately, about 95 percent UV-B rays are absorbed by ozone in the Earth's atmosphere. 87. Although we cannot see UV light, bees, bats, butterflies, some small rodents and birds can. 88. UV rays are easily blocked by clothing. 89. UV Helps body make vitamin D for healthy bones and teeth. 90. UV Used to sterilize medical supplies & equip because they kill bacteria. 91. UV as a Detectives use fluorescent powder (absorbs UV & glows) to find fingerprints. 92. Gama, X-ray and ultraviolet are the ionizing radiation and have a harmful effect in our body tissue. 93. The near infrared rays are the most penetrating in the infrared range ‫االشعة تحت الحمراء القريبة هي االكثر عمقا‬.‫لالختراق من بين مدي االشعة تحت الحمراء‬ 94. Ozone layer decreasing due to CFCs in AC, refrigerators, & cleaning fluids. 95. breakdown of the ozone layer increases skin cancer and cataracts in humans, impairs immune systems of all animals (including humans). 96. Negative effects include increases in certain types of skin cancers, eye cataracts and immune deficiency disorders. 97. UV radiation affects terrestrial and aquatic ecosystems, altering growth, food chains and biochemical cycles. 98. Aquatic life just below the water’s surface, the basis of the food chain, is particularly adversely affected by high UV levels. 99. UV rays affect plant growth, reducing agricultural productivity. 100. X- Rays and Gamma Rays Both can be used in radiation therapy to kill diseased cells. 101. Both MRIs and X-rays produce images of tissues and other structures inside of your body. 4 102. Heart failure, kidney stones, bowel obstructions and arthritis all of these diseases we can use X-ray to diagnose it. 103. Why are ultraviolet (UV), X-ray, and Gamma Ray dangerous? I. These are high-energy forms of radiation. II. These are ionizing radiation. III. They have enough energy to break chemical bonds in cells - like in strands of DNA. 104. Electrical conductors: are materials in which some of the electrons are free from the bound with the atoms and can move relatively free through it. 105. Electrical insulators: are materials in which all electrons are bounded to atoms and cannot move freely through the material. 106. Semiconductors: are a third class of materials, and their electrical properties are somewhere between those of insulators and conductors. 107. Superconductors: are materials with zero resistance and in which large number of the electrons are free to move through the material. 108. these materials usually are thermally treated conductor materials and may kept in low temperature. 109. like charges repel one another and unlike charges attract one another. 110. The coulomb force is inversely proportional to the square of the separation r between the particles and directed along the line joining them. 111. The coulomb force is proportional to the product of the charges q1 and q2 on the two particles. 112. The coulomb force is attractive if the charges are of opposite sign and repulsive if the charges have the same sign. 113. Electric field lines emanate from positive charges and penetrate into negative charge. 114. The electric field strength is independent of the charge placed in it. 115. The motion of the free electrons inside the material under the effect of the electric field is called the electronic motion. 116. The motion of the dissociated ions inside the material is called the ionic conduction. 117. The electric current pathing through across section area in the conductor given by. 118. The current density 119. Direct current (DC) has a constant value and direction and independent on time, given by 120. Alternating Current (AC) don`t has constant value and direction and depend on time, given by 121. A capacitor is a device that stores electrical charge. 122. The energy stored in a capacitor given by 123. The capacitance of the capacitor given by 124. Outside the cell mainly the charge is positive. 125. Inside the cell mainly the charge is negative. 126. Cell membrane thickness is ~ 5 nm. 127. Cell membrane capacity is ~ 10 mF m-2. 128. Cell membrane dielectric constant is ~ 5. 129. Potential difference across the cell membrane is 90 mV. 5 130. The chemical potential across the cell membrane is measured by the Nernst equation ( ). 131. The cell membrane is then acts as a capacitor with positively charged outside and negatively charged inside. 132. Isolates the cell’s contents from the external environment. 133. Regulates the exchange of substances across the membrane, bio-membranes have a selectively permeable structure. 134. Communicates with other cells and Receive and perform the information, Creates attachments within and between cells. 135. Regulates many biochemical reactions like transforming the metabolic energy in osmotic, electric or mechanical work and many other processes. 136. Diffusion is the movement of molecules from higher concentration to lower concentrations i.e., according to concentration gradient. 137. Passive transport it`s the mechanism of molecular movement through openings in the membrane or in a combination with a protein without needing any energy. 138. Concentration is the number of molecules of a substance in a given volume or fluid. 139. Active transport it`s the mechanism of moving substances through the membrane in combination with a carrier protein, against gradient, and with the need of energy. 140. Sodium-potassium pump is a protein that maintains the internal concentration of potassium ions [K+] higher than that in the surrounding medium (blood, body fluid, water) and maintains the internal concentration of sodium ions [Na+] lower than that of the surrounding medium. 141. Sodium-potassium pump: Maintain the cell membrane potential (more negative inside than outside). 142. Sodium-potassium pump: Control the cell volume by controlling the Na+ ions concentration as Na+ ions are water-attracting ions. Provide the force required to import glucose, amino acids and other nutrients into the cell. 143. Un-phosphorylated pump has higher affinity for Na+, while phosphorylated pump has higher affinity for K+. 144. Peripheral nervous system is everything else the brain and the spinal cord. 145. The nervous system transmits messages in the form of electrical pulses. 146. The electrical impulse travels along the muscle cell to initiate its contraction. 147. Dendrites: pick up the information. 148. Soma (Cell body): processes the information. 149. Myelin sheath: starts the excitation and increases the pulse propagation speed. 150. Axon: propagates the information. 151. Terminal buttons: transfer the information to the next cell. 152. Sensory neurons: receive stimuli from sensory organs and convey messages such as heat, light, pressure, muscle tension and odor to higher centers in the nervous system. 153. Motor neurons: carry messages provided by the sensory neurons or the central nervous system to control the muscles. 154. Inter neurons: transmit information between neurons. 155. The action potential starts if the nerve impulse exceeds a certain threshold value, resulting in changing the potential inside the membrane with about 20 mV (from -70mV to about - 55mV). 156. Refractory time is the minimum time required to restore the membrane potential, OR the minimum time between two sequential impulses. 6 157. Absolute refractory period: a new action potential cannot absolutely be initiated during this period. It includes the depolarization stage and extends until the membrane repolarizes. 158. Relative refractory period: a new action potential may be initiated during this period. This period starts directly after the relative refractory period. This period includes the hyper-polarization stage until the return to the resting state. Re-stimulation during this period requires greater stimulus. 159. Saltatory Conduction, it’s the propagation or “hopping” of action potentials along axons from one node of Ranvier to the next node. 160. The gap between the nerve ending and the next cell is called synapse. 161. Conduction in synapse takes place in only one direction in a manner similar to P-N junction diode rectifier. 162. Myelination increases the conduction velocity of action potential and makes them more energy- efficient. 163. In all the synaptic conduction, except for the crayfish, the transmission is chemically assisted by positive transmitter called Acetylcholine ACL. 7