Chapter 1: Cellular Biology

Kylinn Walston

RADT 3143

Chapter 1: Cellular Biology

1-1. Explain how the structure of the plasma membrane influences the movement of oxygen, carbon dioxide, and sodium ions.

a. The plasma membrane is extremely important because of its multi-functionality to each cell, it is what keeps the cell complete. The membrane structure is determined by the lipid bilayer, and proteins determine the membrane functions. The membrane has a lipid bilayer containing hydrophobic and hydrophilic regions. This bilayer blocks hydrophilic substances from passing while still allowing water diffusion. This allows oxygen and carbon dioxide molecules, both lipid-soluble molecules, to diffuse through the bilayer easily. Water molecules, due to their small size,

Modes of inheritance can be described as the patterns of inheritance of how a disease is transmitted in families. If there are known factors about the mode of inheritance, information about the disease gene itself can be revealed. Four modes of inheritance for single genetic diseases are: autosomal dominant, autosomal recessive, X-linked dominant, and X-linked recessive. Autosomal dominant and autosomal recessive involve genes that occur on 22 pairs of autosomes. X-linked dominant and X-linked recessive, as their name implies, occurs on the X chromosome. (Huether 47) Autosomal dominant and X-linked dominant are similar in the matter that they both only require one copy of a diseases allele to express the phenotype in a at risk person. While on the other hand, autosomal recessive and X-linked recessive require two copies of the disease allele in order to have an individual become susceptible. (Genetics

The most important intracellular buffer systems are phosphate and protein. The most important plasma buffer systems are carbonic acid-bicarbonate and the protein hemoglobin. The carbon acid-bicarbonate buffer is a major extracellular buffer and operates within the lungs and the kidneys. To decrease the amount of carbonic acid the lungs function to remove carbon dioxide and leave water remaining. In turn, the kidneys use the carbon dioxide and water to create or absorb bicarbonate. The lungs and kidneys work hand in hand because the lungs adjust the acid concentration quickly while the kidneys reabsorb or produce bicarbonate. What the lung and the kidney are doing for each other is termed compensation. Protein buffering is used in both intracellular and extracellular buffering. Proteins are considered negative buffers and pair well with hydrogen. An intracellular blood buffer like hemoglobin is used because it binds well with hydrogen ions and carbon dioxide. The venous blood, or hemoglobin that isn’t saturated with oxygen, is a better buffer than arterial blood. The phosphate buffer system is important because it regulates the pH in the cytosol. Dibasic phosphate and ammonia are considered renal buffers. Once buffered, the hydrogen is secreted and buffered within the lumen by phosphate and ammonia. As stated above in the carbonic acid-bicarbonate, the bicarbonate is then reabsorbed. This results in new bicarbonate within the plasma. This attributes to the