PBIO 004 Lecture Notes - Lecture 2: Cell Membrane, Cell Wall, Plant Cell
19 Jan 2019
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Document Summary
Plant cells have different shapes and have different functions: shape and function linked in biology. Many cellular components shared between organisms, but some are specific to plants: plasmodesmata, cell wall, central vacuole, chloroplast and plastids. Cell wall is the outermost layer of a cell and cellulose is the most abundant component of cell walls: primary cell wall is formed during cell division, secondary cell wall is formed after cell growth has stopped. Mitochondria engulfed first, chloroplasts not until animals, fungi and plants diverged evolutionarily, which is why only plants have them. Membranes differ based on the proteins within them, giving unique function: membrane proteins form pores, channels or pumps to transport molecules across the membrane. Transport without pores would be difficult due to the polarity of phospholipids and water. Mitochondria are the powerhouse of the cell because they contain atp, the energy currency use to covert co2 to sugar in the chloroplast: composed of an inner and an outer membrane.
