combined set exam 4

LECTURE 49 POWERPOINT INFO

LECTURE 49 POWERPOINT INFO

H+

Acids are _____ donors

acceptors; OH-

Bases are H+ _____ or give up _____ in solution

dissociate completely

If an acid or base is strong, what happens to it in a solution?

strong

HCl and NaOH are [strong/weak]

dissociate only partially

If an acid or base is weak, what happens to it in a solution?

weak

Carbonic acid (H2CO3) is [strong/weak]

H+

What is the "holy grail" of acid-base?

true

T/F - Small changes in pH can produce major disturbances in physiology

narrow

Most enzymes function within a very [narrow/broad] pH range

less

Small changes in pH can cause membrane potential to be altered and usually becomes [more/less] negative (depolarizes)

true

T/F - Small changes in pH can cause hormones to become less effective

is

Homeostasis of pH [is/is not] tightly controlled

7.4

What is the pH of extracellular fluid?

7.35-7.45

What is the pH of blood?

6.8; 8.0

When the pH is < _____ or > _____, death occurs

falls below 7.35

Acidosis (acidemia) occurs when pH _____

rises above 7.45

Alkalosis (alkalemia) occurs when pH _____

acids

Does the body produce more acids or bases?

foods

Acids are taken in with _____

lipids; proteins

Acids are produced by metabolism of _____ and _____

CO2

Cellular metabolism produces _____

CO2 -

Volatile acid (Lung) is mostly _____

non-volatile

Fixed Acids (Kidney) are [volatile/non-volatile]

1. phosphoric acid

2. sulfuric acid

3. lactic acid

4. keto-acids

What are the fixed acids of the kidney?

membrane lipid breakdown

Phosphoric acid comes from...

protein breakdown

Sulfuric acid comes from...

ischemia & hypoxia

Lactic acid comes from...

disease (diabetes)

Keto-acids come from...

buffers

_____ control acid production

H+

Buffer systems resist change in pH by taking up or releasing _____ as conditions change

buffer pair

The pairing of H2CO3 with bicarbonate (HCO3-) is an example of what?

weak acid and conjugate base

Key: weak acids donate H+ while conjugate base accepts H+ and together they resist pH changes

What does a buffer pair consist of?

true

T/F - Buffer systems result in a smaller change in pH

resist

A mixture of a weak acid and conjugate base _____ a change in pH+

1.0; 7.4

Effective buffers have a pK within _____ and pH unit of _____

LECTURE 49 PRACTICE QUESTIONS

LECTURE 49 PRACTICE QUESTIONS

B) pH levels affect enzyme function, membrane potential, and hormone effectiveness

Why is maintaining the body's pH important for homeostasis?

A) pH levels determine hydration status

B) pH levels affect enzyme function, membrane potential, and hormone effectiveness

C) pH levels are only important in digestive health

D) pH levels only impact blood oxygenation

C) 7.35 - 7.45

What is the normal pH range for blood?

A) 6.0 - 6.5

B) 7.0 - 7.2

C) 7.35 - 7.45

D) 7.8 - 8.2

C) Depolarization of membrane potential

Which of the following changes can result from small shifts in body pH?

A) Increased enzyme function

B) No effect on body processes

C) Depolarization of membrane potential

D) Stronger hormone binding

A) Cellular metabolism producing CO₂

Which of the following is a major source of hydrogen ions in the body?

A) Cellular metabolism producing CO₂

B) Absorption of calcium from food

C) Breakdown of glucose in the intestines

D) Protein synthesis

A) Volatile acids can be excreted by the lungs, fixed acids are excreted by the kidneys

What is the primary difference between volatile and fixed acids?

A) Volatile acids can be excreted by the lungs, fixed acids are excreted by the kidneys

B) Volatile acids are solids, fixed acids are gases

C) Fixed acids can be excreted by the lungs, volatile acids by the kidneys

D) Both are eliminated through the skin

B) Calculate the pH of a solution

The Henderson-Hasselbalch equation is used to:

A) Predict blood glucose levels

B) Calculate the pH of a solution

C) Determine blood pressure

D) Assess hydration status

B) A substance that donates hydrogen ions

An acid is defined as:

A) A substance that accepts hydrogen ions

B) A substance that donates hydrogen ions

C) A substance that donates OH- in solution

D) A neutral substance

B) Bicarbonate buffer

Which buffer system is the main buffer in extracellular fluid?

A) Phosphate buffer

B) Bicarbonate buffer

C) Protein buffer

D) Ammonia buffer

B) Sulfuric acid

Which of these acids is classified as a fixed acid?

A) Carbon dioxide

B) Sulfuric acid

C) Hydrochloric acid

D) Nitrous acid

B) 6.8 - 8.0

What pH range is considered compatible with life?

A) 5.5 - 6.5

B) 6.8 - 8.0

C) 7.2 - 8.5

D) 6.5 - 7.5

B) A deficiency in CO₂

Respiratory alkalemia is usually caused by:

A) An excess of CO₂

B) A deficiency in CO₂

C) High levels of lactic acid

D) Low levels of ketones

C) Dissociates completely in solution

A strong acid differs from a weak acid in that it:

A) Is unable to dissociate in solution

B) Dissociates only partially in solution

C) Dissociates completely in solution

D) Reacts only in non-aqueous solutions

B) It relates pH to pKa and the concentration of acid/base

Which of the following is true of the Henderson-Hasselbalch equation?

A) It predicts hydration needs

B) It relates pH to pKa and the concentration of acid/base

C) It calculates total blood volume

D) It measures body temperature

B) It can be eliminated by the lungs as CO₂

What characterizes a volatile acid?

A) It is excreted through the skin

B) It can be eliminated by the lungs as CO₂

C) It is produced in bone marrow

D) It only accumulates during dehydration

B) Blood pH above 7.45

What does the term "alkalosis" mean?

A) Blood pH below 7.35

B) Blood pH above 7.45

C) Normal blood pH

D) Blood pH equal to 7.4

C) Respiratory changes

Which mechanism helps regulate blood pH on a short-term basis?

A) Liver detoxification

B) Cellular division

C) Respiratory changes

D) Bone marrow function

B) 1.0 pH unit

Effective physiological buffers usually have a pK within how many pH units of 7.4?

A) 0.5 pH units

B) 1.0 pH unit

C) 2.0 pH units

D) 3.0 pH units

B) Lowers it below 7.35

What effect does metabolic acidosis have on blood pH?

A) Raises it above 8.0

B) Lowers it below 7.35

C) Has no effect on pH

D) Raises it to 7.45

B) By converting HCO₃⁻ and H+ to CO₂ and H₂O

How does the bicarbonate buffer system resist pH change?

A) By adding OH- ions

B) By converting HCO₃⁻ and H+ to CO₂ and H₂O

C) By binding with calcium ions

D) By releasing hydrogen ions into the blood

A) Elevated CO₂ due to hypoventilation

Which of the following describes a respiratory cause of acidemia?

A) Elevated CO₂ due to hypoventilation

B) Excess bicarbonate in the blood

C) Decreased lactic acid levels

D) Hyperventilation increasing CO₂ levels

LECTURE 50 POWERPOINT INFO

LECTURE 50 POWERPOINT INFO

chemical buffer system

What is the 1st line of defense against pH shift?

physiological buffers

What is the 2nd line of defense against pH shift?

chemical buffer system

The following are associated with [the chemical buffer system/physiological buffers]:

-bicarbonate buffer system

-phosphate buffer system

-protein buffer system

physiological buffers

The following are associated with [the chemical buffer system/physiological buffers]:

-respiratory mechanism (CO2 excretion)

-renal mechanism (H+ excretion)

immediate (sec)

H+ load -> extracellular buffering by HCO3-. How quickly/slowly does this happen?

hours to days

H+ load -> increase renal H+ excretion. How quickly/slowly does this happen?

up to 4 hours

H+ load -> intracellular buffering (such as hemoglobin). How quickly/slowly does this happen?

minutes

H+ load -> respiratory buffering by PCO2. How quickly/slowly does this happen?

extracellular buffer

Bicarbonate (HCO3-) is a _____

20:1 (HCO3-:H2CO3)

Sodium Bicarbonate (NaHCO3) and carbonic acid (H2CO3) maintain a _____ ratio

intracellular

Phosphate is a major _____ buffer

intracellular

The following are _____ buffers:

1. Bicarbonate-carbonic acid

2. Hemoglobin (Hb)

3. Proteins (Imidazole of histidine and 𝛂-amino acids)

4. Organic Phosphates (ATP)

respiratory buffering

Exhalation of carbon dioxide is an example of a _____ mechanism

volatile

Respiratory buffering mechanisms only work with _____ acids

fixed

Respiratory buffering doesn't change _____ acids like lactic acid

breathing

Body pH can be adjusted by changing rate and depth of _____

renal buffering

_____ mechanisms eliminate large amounts of acid

true

T/F - Renal buffering mechanisms can also excrete base

kidneys

If _____ fail, pH balance fails

bicarbonate

Renal buffering mechanisms can conserve and produce _____ ions

HCO3-

With renal buffering mechanisms, elimination of acid occurs by reabsorption of _____

fixed/non-volatile acid

With renal buffering mechanisms, elimination of acid occurs by excretion of _____

buffered

Fixed acids must be _____ until excreted

1. titratable acid (inorganic phosphate)

2. ammonium (NH4+)

What are the 2 methods of excreting a fixed acid in renal buffering?

acidemia

If kidneys fail, pH balance fails, leading to _____

titratable acid

H+ excreted by urinary buffers

50

Total production of fixed H+ (mEq/day) in normal condition

20

Excretion of H+ as titratable acid (mEq/day) in normal condition

30

Excretion of H+ as NH4+ (mEq/day) in normal condition

500

Total production of fixed H+ (mEq/day) in diabetic ketoacidosis

50

Total production of fixed H+ (mEq/day) in chronic renal failure

100

Excretion of H+ as titratable acid (mEq/day) in diabetic ketoacidosis

10

Excretion of H+ as titratable acid (mEq/day) in chronic renal failure

400

Excretion of H+ as NH4+ (mEq/day) in diabetic ketoacidosis

5

Excretion of H+ as NH4+ (mEq/day) in chronic renal failure

LECTURE 50 PRACTICE QUESTIONS

LECTURE 50 PRACTICE QUESTIONS

B) H-H (Henderson-Hasselbalch) approach

Which of the following approaches calculates blood pH based on bicarbonate and carbonic acid concentrations?

A) Anion Gap

B) H-H (Henderson-Hasselbalch) approach

C) Stewart approach

D) Titratable Acid approach

B) Metabolic acidosis

The Anion Gap approach is most useful in diagnosing:

A) Respiratory alkalosis

B) Metabolic acidosis

C) Respiratory acidosis

D) Alkalosis in general

B) Strong ions and weak acids in plasma

What does the Stewart approach focus on for diagnosing acid-base abnormalities?

A) Bicarbonate and carbonic acid concentrations

B) Strong ions and weak acids in plasma

C) Ammonium levels

D) Sodium and chloride concentrations only

D) Bicarbonate buffer

Which buffer system involves sodium bicarbonate and carbonic acid?

A) Phosphate buffer

B) Protein buffer

C) Hemoglobin buffer

D) Bicarbonate buffer

C) 20:1

What ratio of bicarbonate (HCO₃⁻) to carbonic acid (H₂CO₃) is needed to maintain blood pH near 7.4?

A) 10:1

B) 15:1

C) 20:1

D) 30:1

C) Phosphate

Which buffer system is the major intracellular buffer?

A) Hemoglobin

B) Bicarbonate

C) Phosphate

D) Plasma proteins