Chapter 5 · Biology
Life Processes
Nutrition, respiration, transport and excretion are all rate processes — and rates can be calculated. The live module runs the real physiological formulas for heart output, pulmonary ventilation and glomerular filtration.
Life Processes Lab
Explore digestion, respiration, transport and excretion with step-by-step, computed physiology.
- Mouth
- Starch → Maltose
- Oesophagus
- Bolus transported to stomach
- Stomach
- Proteins → Peptones
- Small intestine
- Peptones→Amino acids; Fats→Fatty acids+Glycerol; Starch→Glucose
- Large intestine
- Water & salts absorbed; faeces formed
Formula sheet
Photosynthesis
6CO₂ + 12H₂O →(light, chlorophyll) C₆H₁₂O₆ + 6O₂ + 6H₂O
Autotrophic nutrition converts light energy into chemical energy.
Aerobic respiration
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 38 ATP
Complete oxidation in the mitochondria.
Anaerobic (yeast)
Glucose → 2 Ethanol + 2CO₂ + 2 ATP
Fermentation; occurs without oxygen.
Anaerobic (muscle)
Glucose → 2 Lactic acid + 2 ATP
Causes cramps during vigorous exercise.
Cardiac output
CO = Heart rate × Stroke volume
Typically 72 × 70 mL ≈ 5 L/min.
Pulmonary ventilation
PV = Tidal volume × Breathing rate
About 500 mL × 15 = 7.5 L/min at rest.