BIOL 111 Lecture Notes - Lecture 9: Transpiration, Phloem, Semipermeable Membrane

• School: McGill University
• Department: Biology
• Course: BIOL 111
• Professor: Rudiger Krahe

Document Summary

1. plants need to acquire organic and inorganic materials. 2. organic material, c, h and o are obtained from atmosphere and water. 3. inorganic materials such as chemical nutrients are obtained from soil along with water. 4. the processes of acquisition and distribution of materials involve transport of materials. 1. transport by bulk flow (driven by pressure difference between the two ends) 2. diffusion (due to inherent thermal energy of molecules. Involves no applied force, concentration gradient provides the direction) A semi-permeable membrane allows solvent but not solute molecules to pass through. ) 4. facilitated transport by carrier proteins, membrane channels and by energy-requiring pumps. Endodermis is the entry checkpoint in plant structure. In plants, 80% of growth is due to cell expansion and 20% to cell numbers. Plants put h on the c to make food for themselves and to be stolen by animals. Animals, although free- living, are eternal parasites on plant life.