Buffer Systems in the Body

Flashcards for reviewing key concepts related to buffer systems in the body.

What is the pH of a neutral solution?

7

What pH indicates an acidic solution?

Less than 7

What pH signifies a basic solution?

Greater than 7

If Ka > Kb, what is the pH of the solution?

Acidic

What happens to pH if Ka = Kb?

pH is neutral

Calculate pH of 0.1 M CH3COONa (pKa = 4.75).

pH = 8.87

What is the dissociation of CH3COONa in solution?

CH3COONa ⇌ CH3COO- + Na+

What is the formula for finding Kb from Ka?

Kb = Kw / Ka

What is the value of Kw at 25°C?

1 x 10^{-14}

How do you convert pKa to Ka?

Ka = 10^{-pKa}

What does a buffer system do?

Resists changes in pH when acids or bases are added.

What are the major buffer systems in the human body?

Bicarbonate buffer, phosphate buffer, and proteins.

What is the normal blood plasma pH range?

7.35 - 7.45

What can happen if pH < 6.9 or pH > 7.6?

It can be life-threatening.

What is a buffer?

A chemical equilibrium system that resists changes in pH.

What is the bicarbonate buffer equation?

CO2 + H2O ⇌ H2CO3 ⇌ H3O+ + HCO3-.

What is the role of proteins as buffers?

They react with acids or bases to prevent pH changes.

What is acidosis?

An abnormal increase in acid levels in blood.

What is the difference between respiratory and metabolic acidosis?

Respiratory acidosis is due to CO2 retention; metabolic acidosis is due to excess H+.

What causes respiratory acidosis?

Inefficient CO2 removal from the blood.

What compensatory mechanism occurs during respiratory acidosis?

Increased rate of breathing.

What compensates for metabolic acidosis?

Increased rate of breathing and renal excretion of acids.

What is alkalosis?

An abnormal decrease in acid levels in blood.

What are the causes of respiratory alkalosis?

Rapid expulsion of CO2 due to hyperventilation.

What happens during metabolic alkalosis?

Increase in alkaline components like HCO3-.

What is the pH of blood during alkalosis?

Increases above normal.

How does the carbonic acid-bicarbonate buffer respond to added acid?

Increases H3O+ concentration, drives reaction left.

What happens when a strong base is added to the bicarbonate system?

Decreases H3O+, drives reaction right.

What is the equilibrium shift according to Le Chatelier's principle?

The system shifts to counteract changes in equilibrium.

How much carbonic acid is produced daily in the body?

10-20 moles.

What is the phosphate buffer system primarily responsible for?

Buffering pH inside cells.

What is the dissociation of H2PO4-?

H2PO4- ⇌ H3O+ + HPO42-.

What effect does adding a strong acid have on the phosphate buffer?

Increases [H2PO4-] and drives reaction left.

What compensatory actions can the kidneys perform during acidosis?

Increase HCO3- retention and H+ excretion.

What are OH- ions' role in buffer systems?

React with H3O+ to maintain pH.

What is a common symptom of metabolic acidosis?

Increase respiration rate.

What is the primary response to metabolic alkalosis?

Decrease respiration rate.

What defines proteins as amphoteric molecules?

They can act as either acids or bases.

What does pH represent in terms of hydrogen ion concentration?

Negative logarithm of H+ ion concentration.

What is the expected blood pH during respiratory alkalosis?

Increased above 7.4.

What is the primary source of acid in the body?

Metabolic reactions.

How does increasing HCO3- in the blood affect pH?

It increases blood pH.

What is the long-term compensation mechanism during chronic acidosis?

Kidneys adjust HCO3- level.

Describe the role of carbon dioxide removal in respiratory control of pH.

Exhalation maintains pH by removing excess H2CO3.

What indicates the presence of metabolic alkalosis?

Increased blood pH due to loss of acid or gain of base.

What is the significance of the pH range in blood plasma?

Critical for physiological functions and enzyme activity.

In acid-base balance, what does the urine's pH indicate?

The body's compensatory status regarding acidity.