2. in psychiatry, an unconscious defense mechanism in which unacceptable ideas, fears, and impulses are thrust out or kept out of consciousness. 3. gene r. enzyme repression interference, usually by the endproduct of a pathway, with synthesis of the enzymes of that pathway. gene repression the inhibition of gene transcription of an operon; in prokaryotes repressor binding to the operon is involved.
Hyperkalemia can result from increased potassium intake, decreased potassium excretion, or a shift of potassium from the intracellular to the extracellular space. The most common causes involve decreased excretion. Alone, excessive intake or an extracellular shift is distinctly uncommon.
Sodium-potassium pumps maintain a low intracellular concentration of sodium ions. BIOLOGY I. Chapter 7 â Cell Membrane Structure and Function Evelyn I. Milian-Instructor 40 SECONDARY ACTIVE TRANSPORT ACROSS THE PLASMA MEMBRANE FIGURE 3.12 â Secondary active transport mechanisms.