Human Nutrition

• Heterotroph: organisms that cannot make their own food
• Autotroph: organism that can produce its own food from simple substances such as carbon dioxide, water and minerals.
• Digestion: the breakdown of large food molecules into smaller soluble ones
• Mechanical digestion: the breakdown of food into smaller pieces by physical means such as teeth, chewing, churning
• Chemical digestion: the breakdown of food into smaller molecules by enzymes, stomach acid or bile
• Peristalsis: the waves of muscular contraction of the gut wall that moves the food along
• Symbiotic bacteria: bacteria that live in or on another organism where at least one benefits