Untitled Quiz

Water Properties

• Incompressibility: This ensures that water can be used for support, like the turgor pressure in plants.
• Density: Water is most dense at 4°C. Ice (solid water) floats on liquid water due to a 9% decrease in density upon freezing, which insulates ponds and provides habitat for penguins.
• High Latent Heat: Water requires a lot of energy to change its state, making it a stable environment for organisms due to less evaporation and freezing.
• High Specific Heat Capacity: Water requires a lot of energy to change its temperature, making it a stable environment. This also helps in maintaining stable body temperature.
• High Surface Tension: Water's surface tension is due to cohesion (attraction between water molecules) and adhesion (attraction between water and other surfaces). This tension is responsible for things like water droplets formation.
• Amphoteric: Water can act as both an acid and a base, donating or accepting protons.

pH

• Acids: Release H+ ions in solution. Strong acids ionize completely, while weak acids only partially ionize.
• Bases (Alkalines): Release OH- ions in solution or accept protons. Strong bases ionize completely, while weak bases only partially ionize.
• Amphoteric Substances: Act as both acids and bases, like water and amino acids.

pH Importance

• Blood pH: 7.1 - 7.4 (any changes can be fatal)
• Urine pH: 6.8 (slightly acidic) Changes in pH can lead to the precipitation of salts and the formation of urinary stones.
• Gastric Juice pH: 1.5 - 2 (highly acidic) Increased acidity can lead to peptic ulcers, and decreased acidity can lead to hypoacidity.
• General: All reactions in living protoplasm occur in buffered media. Any pH abnormality can lead to illness and potentially fatal conditions.

Physiological Buffers

• Bicarbonate Buffer (H2CO3, NaHCO3): Most important buffer in the blood. It helps regulate pH by releasing or absorbing H+ ions.
• Phosphate Buffer (NaH2PO4, Na2HPO4): Main buffer of the urinary system.
• Hemoglobin Buffer: This buffer controls sudden additions of acid or base.
• Proteins and Amino Acids: Act as important buffers in blood and tissues.

Acid-Base Balance

• Body uses three mechanisms:
  • Buffering agents
  • Respiratory system
  • Renal system
• Acidosis: Arterial pH below 7.35.
• Alkalosis: Arterial pH above 7.45

Types of Acidosis/Alkalosis

• Primary Respiratory Disturbances: Occur due to changes in CO2 levels.
• Primary Metabolic Disturbances: Occur due to changes in bicarbonate levels.

Acidosis

• Primary Respiratory Acidosis: Occurs when PCO2 is above 45 mmHg. Causes include acute and chronic pulmonary insufficiency.
• Primary Metabolic Acidosis: Occurs when bicarbonate levels are below 22 mEq/liter. Causes include diarrhea, carbonic anhydrase inhibitors, lactic acidosis, keto-acidosis, and aspirin poisoning.

Alkalosis

• Primary Respiratory Alkalosis: Occurs when PCO2 is below 35 mmHg. Causes include hyperventilation, fever, and high altitudes.
• ** Primary Metabolic Alkalosis:** Occurs when bicarbonate levels are above 29 mEq/liter. Causes include loss of gastric HCl, administration of diuretics.

Acidosis and Alkalosis Compensation

• Body compensates for acid-base imbalances by:
  • Respiratory system: Adjusting CO2 levels.
  • Renal system: Regulating bicarbonate levels.