TOPIC 3 WATER

Water comprises half of the total body weight

___- ___% in humans

___- ____% in animals

45-75% in humans

55-75% in animals

Fxns of water in the body

• lAs c________________

• As solvent for ____and macromolecules

• As _______ for transport

• Acts as ______________

• helps _____________________

• chemical reactant

• ions and macromolecules

• medium

• lubricant

• regulate body temp

Most of the functions of water is due to _________________________

its physical properties

Hydrogen end of water is

positive pole

Specific gravity of water

1.0 (1ml = 1 gram)

Maximum density of water

occurs at 4c

hindi basta basta tataas ang temperature sa body compartments

because of high specific heat

•Frozen water forms a crystal-like lattice whereby molecules are set at ______ distances.

fixed

lWater can absorb or release large amounts of heat energy with little change in actual temperature.

High specific heat

•____________- amount of heat needed to raise the temperature of 1 g of a substance by 1° C.

Specific heat

_____________________-amount of energy to convert 1g of a substance from a liquid to a gas

lHeat of vaporization

Water's heat of vaporization is ____cal/g

540

Water can ionize thrpough

Intermolecular proton transfer

Water can dissociate to:

• Hydrogen ion

• Hydroxide ion

___________- can act both as acid and as a base

Amphoteric

Most important source of water

metabolic sources

lSources of H⁺ in the body:

1. __________________

2. metabolic sources

water dissociation

___ = proton released when hydrogen loses its electron

H⁺

pH is

concentration of hydrogen (usually polar)

the more cells metabolize glucose, the more

carbon dioxide

lThe CO₂ _______________ and reacts with water:

diffuses into the blood

responsible for the majority of H⁺ generated each day.

continous producction of CO2

can react with bicarbonate forming CO2, released via the lungs

volatile acids

lMetabolism of sulfur-containing_______________(e.g., methionine and cysteine) produces __________________,

amino acids . sulfuric acid (H₂SO₄)

Non va are excreted via

kidneys

released only in abnormal/pathologic conditions

organic acids

strenuous exercise, shock, poor tissue perfusion

Lactic acid

starvation, diabetes mellitus, pregnancy toxemia in ruminants

Ketone bodies

The amount of hydrogen ions present in body fluids determines ________

acidity

water has a pH of neutral becasue

same conc of hydrogen ion and hydroxide ion

lNormal arterial blood pH: 7.35–7.45 (≈______)

7.40

lAcidemia: pH < ____

lAlkalemia: pH > _____

7.35

7.45

lApproximate pH range compatible with life: ________

6.8–7.8

strong acids dissociates _________ in water/solution

weak acids dissociates ________ in water/solution

completely

partially

Buffers are mixture of a _________and its ___________ or a mixture of a weak base and its conjugate acid that can accept or donate H⁺, minimizing sudden changes in blood pH.

weak acid, conjugate base

____________ of living organisms contains conjugate acid and base pairs which act as buffers at normal pH of these fluids

ECF and ICF

Major buffer system in ECF

Bicarbonate

Major buffer system in urine

. Inorganic orthophosphates

Major buffer system inside cells (ex: RBCs)

Intracellular proteins (hemoglobin)