Lecture One What is science? A body of knowledge about the natural world. Science is a technique: a way of seeking principles about the world. Science tries to verify these principles via experiments What is life?1. Highly organized (atoms, cells, organisms) 2. Maintain stable composition3. Take & use energy from environment 4. Respond to stimuli 5. Grow and develop 6. Reproduce- sexually or asexually 7. Show variations based on heredity 8. Evolve and adapt to their environmentWhat is a plant?1. Multicellular organism2. Cellulose-rich cell wall3. Chlorophyll and are photosynthetic4. Adapted to life on land (or descended from land plants)Plant Structure is divided into two main parts (shoot & roots)Shoot: usually grows above includes stem, leaves, nodes, internodes, and buds- Flowers- a specialized shoot where reproduction occurs; fruits & seeds develop- Leaves- site of photosynthesis: blade, petiole- Node- place in the stem where a leaf is attached- Stem- holds leaves, transports water & nutrients. Provides support above ground Root: usually below ground, anchors, absorbs water/minerals1. Roots anchor the plant to the soil2. Absorb water and mineral nutrients3. May serve as storage in some species4. Branch roots, root hairs, root capLecture Two- The CellThe molecules of Life - Carbohydrates (sugars, starches, cellulose)- Lipids (fats, oils, waxes, phospholipids, steroids)- Proteins (composed of amino acids)- Nucleic Acids (DNA, RNA)Life’s molecules share the 4 characteristics:1. Carbon-based2. Formed from a few elements: C,H,O,P,N3. Modular construction (like bricks, cheap and easy to build small building blocks)4. Their function depends on structure, OR structure/shape determines function1. CarbohydratesThree types of Carbohydrates (Mono, Di, Poly) Disaccharides- composed of 2 monosaccharides ex- table sugarPolysaccharides- long chains of monosaccharides Function of Carbohydrates- Energy storage - For structure in plant cells (cellulose for cell wall)- Carbon sources to make other molecules (nucleic acids, amino acids)2. Lipids* fats and oils are made from two building blocks* fats are solid lipids at room temp (animal derived: lard, butter)* Oils are liquid lipids (usually plant derived: corn oil, peanut oil, olive oil)* Lipids DO NOT dissolve in
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