NATS 1560 Lecture 2: Topic 2
10 Feb 2023
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Why we need food and how it sustains us. Matter (atoms need them for growth, repair, and functioning of organs and tissues. Energy (capacity to do work - needed for all physiological processes) Food is matter, composed of molecules, broken down into smaller molecules during digestion, and absorbed and used by the body. Matter and energy are not created, destroyed, or transformed into each other, but are separately conserved (conservation of energy/law of thermodynamics) Matter can only transform into energy in nuclear processes such as radioactivity - doesn"t occur in our body. Metabolism: all of the physical and chemical processes that take place inside an organism. Metabolism is the flow of matter and energy (from food) in, through and out the body. Food, energy, cellular respiration, and unused food energy. Three types of energy that can transform into each other: Thermal energy (heat - motions of molecules) Chemical energy (potential energy stored in chemical bonds)
