Acid Base Concepts Flashcards

Questions and Answers

What is pH?

A scale that measures acid/base balance.

Define buffer.

A chemical system that prevents a radical change in fluid pH by dampening the change in H+.

Define acid.

A chemical that takes up H+.

If H+ ions increase, then pH _ and if H+ ions decrease, then pH __.

decrease; increase Signup and view all the answers

Name several important buffer systems that function together to resist change in the pH of body fluids.

Respiratory tract, renal system, plasma proteins, phosphate, bicarbonate, carbonic acid. Signup and view all the answers

Protein buffers: the charged regions of amino acids can bind both _ and __.

H+; OH- Signup and view all the answers

Explain how hemoglobin serves as a buffer.

Hemoglobin buffers hydrogen ions during the conversion of carbon dioxide into bicarbonate. Signup and view all the answers

What are the two forms of phosphate buffers?

Sodium dihydrogen phosphate and sodium monohydrogen phosphate. Signup and view all the answers

What regulates the bicarbonate-carbonic acid buffer?

Regulated in the blood by sodium. Signup and view all the answers

How does the bicarbonate-carbonic acid buffer work?

It reacts with strong acids and bases to maintain pH levels. Signup and view all the answers

Why are there 20 times more bicarbonate than carbonic acid in the body?

Because this buffer system is the most efficient at buffering changes that could make the blood more acidic. Signup and view all the answers

How are bicarbonates supplied? (List 4 steps)

<ol> <li>CO2 diffuses into PCT and combines with water to yield H2CO3. 2. H2CO3 dissociates to form HCO3- and H+. 3. H+ diffuses into filtrate and combines with HCO3-. 4. HCO3- is deleted in filtrate, added to blood.</li> </ol> Signup and view all the answers

What is normal pH?

7.35-7.45 Signup and view all the answers

What is metabolic acidosis?

Occurs when blood is too acidic (below 7.35) due to too little HCO3-. Signup and view all the answers

Explain how diarrhea, uremia, diabetic ketoacidosis, and strenuous exercise cause metabolic acidosis.

Strenuous exercise can produce lactic acid; diabetic ketoacidosis creates excess ketones; diarrhea causes loss of HCO3-; uremia retains urea and uric acid. Signup and view all the answers

What causes metabolic alkalosis?

Cushing's disease, vomiting, potassium depletion due to diuretics, excessive use of laxatives. Signup and view all the answers

Give three examples of conditions that lead to respiratory acidosis.

Pneumonia, emphysema, congestive heart failure. Signup and view all the answers

List several causes of an increase in the respiratory rate that leads to respiratory alkalosis.

Extreme upset/fear, fever, infections, hypoxia, high levels of catecholamines, aspirin overdose. Signup and view all the answers

Study Notes

pH and Buffers

pH is a scale that quantifies acid/base balance.
Buffers are chemical systems that maintain stable fluid pH by moderating changes in H+ concentration.

Acids and their Effects

Acids are chemicals that accept H+ ions and release OH-.
Changes in H+ concentration significantly impact enzyme activity and the rates of chemical reactions.

Buffer Systems

Various buffer systems work together to stabilize body fluid pH:
- Respiratory system regulates blood CO2 through breathing.
- Renal system adjusts H+ excretion and HCO3- conservation.
- Plasma contains buffer systems including plasma proteins, phosphate, bicarbonate, and carbonic acid.

Protein Buffers

Amino acids in proteins can bind to both H+ and OH-.
Protein buffering accounts for two-thirds of blood buffering power and most buffering power within cells.

Hemoglobin as a Buffer

Hemoglobin buffers hydrogen ions generated during the conversion of carbon dioxide to bicarbonate.
The buffering action is reversed in the lungs to release CO2 for exhalation.

Phosphate Buffers

Two forms of phosphate buffers:
- Sodium dihydrogen phosphate (weak acid) reacts with strong acids to form weak acids.
- Sodium monohydrogen phosphate (weak base) interacts with strong bases, converting back to a weak acid and producing water.

Bicarbonate-Carbonic Acid Buffer

Sodium regulates the bicarbonate-carbonic acid buffer system in the blood.
Functions similarly to phosphate buffers; produces H2CO3 with strong acids and HCO3- with strong bases.

Importance of Bicarbonate

There is a predominance of bicarbonate (20 times more than carbonic acid) to effectively manage metabolic acid accumulation, such as lactic acid and ketones.

Bicarbonate Supply Process

CO2 combines with water in the proximal convoluted tubule (PCT) to form H2CO3.
H2CO3 dissociates into HCO3- and H+; H+ is excreted while HCO3- is returned to the blood.

Acid-Base Disorders

Normal blood pH ranges from 7.35 to 7.45.
Metabolic acidosis occurs when blood pH falls below 7.35 due to a decrease in HCO3-.

Causes of Metabolic Acidosis

Conditions like diarrhea (loss of HCO3-), diabetic ketoacidosis (excess ketones), and uremia (urea retention) contribute to metabolic acidosis.
Strenuous exercise can produce temporary lactic acid-induced acidosis.

Metabolic Alkalosis

Metabolic alkalosis is characterized by excess bicarbonate, with causes including Cushing's disease, vomiting (loss of HCl), and potassium depletion from diuretics.

Respiratory Disturbances

Respiratory acidosis arises from respiratory issues (e.g., pneumonia, emphysema, congestive heart failure) leading to increased CO2 and decreased pH.
Respiratory alkalosis occurs from decreased CO2 levels, often due to rapid breathing caused by anxiety, fever, hypoxia, or certain medications.

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Description

Explore essential concepts related to acid-base chemistry through these flashcards. Each card defines key terms such as pH, buffers, and acids. Perfect for students looking to reinforce their understanding of this fundamental topic in chemistry.