Unit A 16 Phys, Acid Base Homeostasis 2. Chemical Buffers

Chemical buffers

pH homeostasis depends on three regulatory systems: _________________, Respiratory System, and Urinary System.

Urinary System

pH homeostasis depends on three regulatory systems: Chemical Buffers, Respiratory System, and ___________________.

Chemical buffers

In pH homeostasis, _____________________ are the 1st line of defense (react immediately) because they react the quickest.

Respiratory system

In pH homeostasis, the _____________________ is the 2nd line of defense (reacts within 1 to 3 minutes).

Urinary system

In pH homeostasis, the _____________________ is 3rd line of defense because it reacts in hours to days. However, it is the most powerful and lasts the longest but reacts the slowest.

Chemical buffers

_________________________ resist changes in pH by combining with H+ when H+ concentrations start to rise or releasing H+ when H+ concentrations start to fall. Buffers maintain the pH around 7.4 and are found within the blood, interstitial fluid, and cells

Decreasing

If an acidic solution is added, the chemical buffer will combine with the extra H+ ions to prevent the pH from ____________ (increasing or decreasing).

Increasing

If a basic solution is added or there is a loss of H+, the buffer will release H+ ions to prevent the pH from ___________ (increasing or decreasing).

Free

Remember the acidity of a solution reflects only the ________ hydrogen ions. Bound hydrogens do not affect pH.

Carbonic acid - bicarbonate

The body has three main chemical buffer systems:

1. The ________________________ buffer system.

2. The protein buffer system

3. The phosphate buffer system

Protein

The body has three main chemical buffer systems:

1. The carbonic acid - bicarbonate buffer system.

2. The _________________ buffer system

3. The phosphate buffer system

Phosphate

The body has three main chemical buffer systems:

1. The carbonic acid - bicarbonate buffer system.

2. The protein buffer system

3. The ____________________ buffer system

Weak

The carbonic acid - bicarbonate buffer system consists of carbonic acid, a ____________ (weak or strong) acid, and bicarbonate, its conjugate base (weak base) and is the fastest acting buffering system in the body.

Aerobic respiration

To form carbonic acid - bicarbonate buffer, the carbon dioxide (CO2) produced from ______________________ by your cells combines with water (H2O) to form carbonic acid (H2CO3), most of which rapidly dissociates to form hydrogen ions (H+) and bicarbonate (HCO3) as shown in the equilibrium reaction.

Law of mass action

According to the _____________________, any change in the amount of CO2, H+, or HCO3− causes the reaction to shift until a new equilibrium is reached. See the equilibrium reaction.

Right

In the carbonic acid - bicarbonate buffering system. If there is an increase in CO2, this would cause the equilibrium to shift to the ____________ (right or left)

Left

In the carbonic acid - bicarbonate buffering system. If there is a decrease in CO2, this would cause the equilibrium to shift to the ____________ (right or left)

Right

In the carbonic acid - bicarbonate buffering system. If there is a decrease in H+, this would cause the equilibrium to shift to the ____________ (right or left)

Left

In the carbonic acid - bicarbonate buffering system. If there is an increase in HCO3-, this would cause the equilibrium to shift to the ____________ (right or left)

Right

In the carbonic acid - bicarbonate buffering system. If there is a decrease in HCO3-, this would cause the equilibrium to shift to the ____________ (right or left)