1. (a) Diffusion refers to the movement of molecules from an area of high concentration to an area of low concentration of those molecules. The factors that influence the rate of diffusion across a membrane are:
~ the extent of the concentration gradient – the greater the difference in concentration on either side of the membrane, the faster the rate of diffusion
~ the mass of molecules diffusing – the heavier they are, the slower they will diffuse across the membrane
~ the distance travelled – this places an upper limit on cell size and functions as a resistance factor; distance travelled is indirectly proportional to the rate of diffusion
~ temperature – higher temperatures increase the kinetic energy of the molecules, therefore increasing …show more content…
in all living cells). It is important for many life processes and, therefore, crucial for physiological function. Without diffusion, cells and body tissue would not be able to obtain important substances (such as nutrients and water from digestion, and oxygen from respiration), nor would they be able to get rid of waste materials. The diffusion of these substances into and out of the cells are essential for keeping the cells alive and fully functional. Therefore, diffusion is necessary in all areas of the human body.
2. Mitochondria are responsible for creating the energy needed to sustain life. Mitochondrial failures lead to mitochondrial disease. It can be caused by inherited or spontaneous mutations in mitochondrial DNA or nuclear DNA, which results in alterations of protein functions or mitochondrial RNA. This causes damage to various organ systems in the body. Symptoms include loss of motor control and muscle coordination, weakness, gastro-intestinal disorders, poor growth, cardiovascular and liver disease, diabetes, respiratory complications, seizures, lactic acidosis, vision/hearing loss, increased risk of infection and learning disabilities. It can be treated by vitamin therapy, energy conservation or pacing activities, maintenance of surrounding temperature, avoidance of exposure to illness, and adequate hydration
~ the extent of the concentration gradient – the greater the difference in concentration on either side of the membrane, the faster the rate of diffusion
~ the mass of molecules diffusing – the heavier they are, the slower they will diffuse across the membrane
~ the distance travelled – this places an upper limit on cell size and functions as a resistance factor; distance travelled is indirectly proportional to the rate of diffusion
~ temperature – higher temperatures increase the kinetic energy of the molecules, therefore increasing …show more content…
in all living cells). It is important for many life processes and, therefore, crucial for physiological function. Without diffusion, cells and body tissue would not be able to obtain important substances (such as nutrients and water from digestion, and oxygen from respiration), nor would they be able to get rid of waste materials. The diffusion of these substances into and out of the cells are essential for keeping the cells alive and fully functional. Therefore, diffusion is necessary in all areas of the human body.
2. Mitochondria are responsible for creating the energy needed to sustain life. Mitochondrial failures lead to mitochondrial disease. It can be caused by inherited or spontaneous mutations in mitochondrial DNA or nuclear DNA, which results in alterations of protein functions or mitochondrial RNA. This causes damage to various organ systems in the body. Symptoms include loss of motor control and muscle coordination, weakness, gastro-intestinal disorders, poor growth, cardiovascular and liver disease, diabetes, respiratory complications, seizures, lactic acidosis, vision/hearing loss, increased risk of infection and learning disabilities. It can be treated by vitamin therapy, energy conservation or pacing activities, maintenance of surrounding temperature, avoidance of exposure to illness, and adequate hydration