buffer

buffer

 [buf´er]

a substance that, by its presence in solution, increases the amount of acid or alkali necessary to produce a unit change in pH. The bicarbonate buffer system in the blood maintains a balance between bicarbonate and carbon dioxide ions and deterimnes the pH of the blood.

Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

buff·er

(bŭf'ĕr),

1. A mixture of an acid and its conjugate base (salt), such as H₂CO₃ or HCO₃^-; H₂PO₄^-/HPO₄^2-, that, when present in a solution, reduces any changes in pH that would otherwise occur in the solution when acid or alkali is added to it; thus, the pH of the blood and body fluids is kept relatively constant (pH 7.45) although acid metabolites are continually being formed in the tissues and CO₂ is lost in the lungs.
See also: conjugate acid-base pair.

2. To add a buffer to a solution and thus give it the property of resisting a change in pH when it receives a limited amount of acid or alkali.

Farlex Partner Medical Dictionary © Farlex 2012

buffer

Chemistry
(1) A chemical system that minimises the effects—in particular the pH—of changes in the concentration of a substance.

(2) A molecule that serves to prevent large changes in pH by either combining with H+ or by releasing H+ into solution. 

(3) A system that minimises the changes in specific chemical species in solution against addition or depletion of the species.

(4) pH buffers: weak acids or weak bases in aqueous solution. The working range is given by pKa +/ 1.

(5) Metal ion buffers: a metal ion chelator (e.g., EDTA), partially saturated by the metal ion acts, as a buffer for the metal ion.

Computers
A storage zone that “resides” temporarily in the RAM (random access memory) and contains either input or output data, remaining there while waiting for an output (or less commonly, an input) device—e.g., a printer—to allow it access to perform a function. Buffer sizes can be increased with “spooling” software or by increased the printer’s RAM.
 
Drug slang
Regional street drug slang for a crack smoker or a woman who exchanges oral sex for crack.
 
Molecular biology
 A solution containing agents which maintain a constant pH during a biochemical reaction.
 
Vox populi
A person who acts as a go-between.

Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

buffer

Chemistry A chemical system that minimizes the effects, in particular the pH, of changes in the concentration of a substance

McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

buff·er

(bŭf'ĕr)

1. A mixture of an acid and its conjugate base (salt), such as H₂CO₃/HCO₃; H₂PO₄/ HPO_4^2-, which, when present in a solution, resists changes in pH that would otherwise occur in the solution when acid or alkali is added to it.
See also: conjugate acid-base pair

2. To add a buffer to a solution and thus give it the property of resisting a change in pH.

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

buffer

a chemical substance which has the capacity to bond to H+ ions, removing them from solution when their concentration begins to rise and releasing H+ ions when their concentration begins to fall. In this way buffers stabilize the pH of biological solutions and are thus important in maintaining HOMEOSTASIS. HAEMOGLOBIN is an excellent example of a buffer, maintaining a stable pH in the ERYTHROCYTE.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005