642
edits
BISC110/S13: Series 1 Lab 1 Boot Camp: Difference between revisions
From OpenWetWare
Jump to navigationJump to search
BISC110/S13: Series 1 Lab 1 Boot Camp (view source)
Revision as of 09:12, 11 January 2013
, 11 January 2013→PART III: Solutions
| Line 90: | Line 90: | ||
'''4. Buffered Solutions''' | '''4. Buffered Solutions''' | ||
A buffered solution resists changes in pH. The pH of a solution is a measure of its acidity, and is defined as the negative log of the hydrogen ion concentration. The pH scale ranges from 0 to 14 where 0 is the most acidic, 14 is the most basic, and 7 is neutral. Since pH is a log scale, the difference between pH 5 and pH 6, for example, is a factor of 10. Buffers are used when biological samples need to be kept within a narrow range of pH to maintain activity. The enzymes involved in biochemical reactions often require a narrow pH range. This range is usually 7.2–7.4 for human and animal tissues. A phosphate buffer is commonly used in the biology laboratory, because it exhibits excellent buffering capacity in the neutral pH range. It is made up of a mixture of sodium monobasic phosphate (NaH<sub>2</sub> | A buffered solution resists changes in pH. The pH of a solution is a measure of its acidity, and is defined as the negative log of the hydrogen ion concentration. The pH scale ranges from 0 to 14 where 0 is the most acidic, 14 is the most basic, and 7 is neutral. Since pH is a log scale, the difference between pH 5 and pH 6, for example, is a factor of 10. Buffers are used when biological samples need to be kept within a narrow range of pH to maintain activity. The enzymes involved in biochemical reactions often require a narrow pH range. This range is usually 7.2–7.4 for human and animal tissues. A phosphate buffer is commonly used in the biology laboratory, because it exhibits excellent buffering capacity in the neutral pH range. It is made up of a mixture of sodium monobasic phosphate (NaH<sub>2</sub>PO<sub>4</sub>) and sodium dibasic phosphate (Na<sub>2</sub>HPO<sub>4</sub>) dissolved in water. | ||
=='''B. Solution Preparation'''== | =='''B. Solution Preparation'''== | ||
