chap 3

• What are the five cations mentioned in the study material?

  Calcium, sodium, potassium, hydrogen, ammonium
• What is the role of calcium ions?

  Nerve impulse transmission and muscle contraction
• What functions do sodium ions serve?

  Nerve impulse transmission and kidney function
• What are the uses of potassium ions?

  Nerve impulse transmission and stomatal opening
• What is the function of hydrogen ions?

  Catalysis of reactions and pH determination
• What do ammonium ions result from?

  Product of nitrate ions by bacteria
• What are the five anions listed in the study material?

  Nitrate, hydrogen carbonate, chloride, phosphate, hydroxide
• What is the role of nitrate ions?

  Nitrogen supply for amino acid and protein formation
• What do hydrogen carbonate ions maintain?

  Blood pH
• What is the function of chloride ions?

  Balance positive charge of sodium and potassium ions
• What are the uses of phosphate ions?

  Cell membrane formation, nucleic acid, ATP, and bone formation
• What is the role of hydroxide ions?

  Catalysis of reactions and pH determination
• What are the four biological molecules mentioned?

  Carbohydrates, lipids, proteins, nucleic acids
• What atoms are present in carbohydrates?

  C, H, O
• What is the general formula for carbohydrates?

  $C_n(H_2O)_n$
• What atoms are present in lipids?

  C, H, O
• What atoms are present in proteins?

  C, H, O, N, S
• What atoms are present in nucleic acids?

  C, H, O, N, P
• Why is water considered a good solvent?

  Water molecules are polar
• How does water's polarity benefit solute molecules?

  Enables water to bind to solute molecules
• How does ice's density contribute to organism survival?

  Ice is less dense than water
• What habitat does ice provide for species?

  Habitat for some species
• How does floating ice benefit aquatic life?

  Insulates water below
• How does water's density relate to living organisms?

  Water is similar in density to organisms
• What does water's density allow organisms to do?

  Organisms can float
• Why is water a good transport medium in blood?

  Water is a liquid
• How does water's polarity affect biological molecules?

  Many biological molecules are polar
• Why is water a coolant in blood?

  Resistant to temperature change
• How does high specific heat capacity benefit aquatic organisms?

  Stabilizes temperatures in aquatic environments
• What is the high latent heat of vaporization's benefit?

  Provides efficient cooling through sweating
• How does ice's density protect aquatic life?

  Creates an insulating layer
• What does cohesion and surface tension allow small organisms to do?

  Move across the water's surface
• Why is water's transparency important for aquatic plants?

  Permits light penetration for photosynthesis
• How does thermal conductivity benefit aquatic life?

  Distributes heat evenly in water
• What does adhesion support in plants?

  Capillary action in water transport
• How does the density of water change as temperature falls?

  Density decreases below 4 °C
• What does floating ice prevent in ponds?

  Prevents water below from freezing
• How does water act as a solvent for ions?

  Dissolves ions like nitrates
• What is the significance of high specific heat capacity for ponds?

  Ensures stable temperature for organisms
• What is the structure of starch composed of?

  Many alpha glucose molecules