Color-coding is effectively used to promote learning. For example, there are specific colors for the extracellular fluid, the intracellular fluid, muscle, and the lumen of the renal tubules and GI tract.
The net mov ment from lower to higher concentration and the raintenance of a higher steady-state concentration or one side of a membrane can be achieved only by the continuous input of energy into the active-transp rt process. This energy can (1) alter the affinity of thejbinding site on the transporter such
Movement of Molecues Across Cell Membranes CHAPTER Sixll the extracellular fluid the protein has been lar surface by when porter is shifted 1 om concenrration (lo -er energy state) to a higher concentration (higher e ergy state), energy must be added. ~ ' .rt must be coupled to the si-
the extracellular fluid bands to th ing site. Random thermal oscillations re to the other, independent of the pthtein's phosphorylation. (3) Removal of the phosphate group from the transporter decreases the affinity of the binding site,
(1) the in primary active transport, and the prioress in secondary active es the .
a is an enzyme (an ATPase) n of ATP and, in the es itself. Phosphorylation of the random oscillation of the transporter (5), it is in a conformation which again permits phosphorylation, and
TCsee why this will lead to movement from low to higher concentration (that is, uphill movement), consider the flow of solute through the trar es of the he transporter at to the high-affinity site at the extracellular surface of the membrane than to the low-affinity site on the in-tracellular surface. T
, 's solute binding site. Figure es the sequence of events leading to the active transport ( hat is, transport from low to higher ' ' a solute into a cell. (1) Initially, the jp transported solute is exposed to
to the high-affinity site at the extracellular surface of the membrane than to the low-affinity site on the in-tracellular surface. T
, 's solute binding site. Figure es the sequence of events leading to the active transport ( hat is, transport from low to higher ' ' a solute into a cell. (1) Initially, the jp transported solute is exposed to potassium and low intracellular sodium potassium and low intracellular sodium
r called parathyroid hormone, . .
nurface of tgie thyaoid gland, but are (Pigune distinct from it. Parathyroid hormone a^drerfy^TÂ^eMy'œlir extracellular calcium concentration, thus for the decreased concentration that of this hormone
ti it it
hormone. See Figure 1
9 for a more complae description of
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This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.