Acid-Base Buffering Flashcards Preview

Module 1: Lecture > Acid-Base Buffering > Flashcards

Flashcards in Acid-Base Buffering Deck (15):
1

What is the purpose of a buffer

Help maintain the acid-base balance for physiological functioning

2

At 25 degrees Celsius, the concentration of pure water

55.5M

3

Normal blood pH

7.4

4

Define acids and bases

Acid is a proton donor; base is a proton acceptor

5

Define Ka (ionization/dissociation constant) of a an acid

The tendency of the acid to lose a proton and form a conjugate base

6

Explain the relationship between acid strength and pKa

The stronger the acid, the lower the pKa

7

Explain short term relief of GERD

Tums (CaCO3) neutralizes the acid in the stomach, end product is CO2 and water; comes out as a burp

8

Explain long term relief of GERD

Omeprazole is a proton pump inhibitor

9

Explain the neutralization zone on titration curve- meaning and what it looks like

This is when the acid is getting neutralized and is a flat zone on the curve

10

How do you tell whether an acid is weak or strong on its titration curve?

Where it's neutralization (flat) zone is

11

What is special about the midpoint of a titration curve?

At the midpoint, the pKa is equal to the pH; [HA] = [A-]

12

What determines if a buffer is efficient or not?

The buffering zone needs to be closer to the physiological pH in order to be an efficient biological buffer

13

Explain Protein Buffer System

Proteins embedded with histidine side chains can act as weak acids or bases, the Histidine side chain pKa is 6.8 which is near 7.4

14

Explain Phosphate Buffer System; and where does it occur?

Occurs in cytoplasm; pKa of 6.8

15

Explain Bicarbonate Buffer system

Normally, bicarbonate has a pKa of 3.8 but carbonic anhydrase catalyzes a reaction with CO2, this has a pKa of 6.1