Lecture 1

• Agriculture was "invented" about 10,000 years ago
• Plants are important because they provide us with many resources
• Many drugs are made from plant secondary compounds
• Secondary compounds are not necessary for metabolism, growth or development
• Secondary compounds can include poisons or deterrents to help plants survive
• Quinine comes from the bark of a Cinchona tree. It was used to treat malaria, also anemia, muscle spasms, cancer and is in tonic water
• Caffeine comes from the berries of the coffee tree
• Aspirin comes from willow species, it is from acetylsalicylic acid. It helps with pain, fever, and inflammation
• Tetrahydrocannibinol (THC) comes from the cannabis plant, this plant has male and female plants
• Nicotine comes from the leaves of a tobacco plant
• Opium, Heroin, Morphine and Codeine come from the opium poppy
• Taxol comes from yew trees. It is a cancer treatment used in chemotherapy for ovarian, breast and lung cancer
• Plants make oxygen and energy used by other components of terrestrial ecosystems
• Botany is the study of plants
• Plants cannot move so they must deal with what happens to them
• "Plants" are all organisms within the clade Viridiplantae
• The clade Viridiplantae includes Cholorophytes, Charophytes and Embryophytes
• Plants (including green algae) and red algae are photosynthetic eukaryotes that arose from a primary endosymbiosis event
• Plants and red algae were formed when a nonphotosynthetic eukaryote engulfed a photosynthetic cyanobacterium
• Other photosynthetic eukaryotes were formed when a nonphotosynthetic eukaryote engulfed a photosynthetic eukaryote (green or red alga) 
• Plants split from red algae about 1.5 billion years ago
• After splitting from red algae, plants could be found in single-cell and multicellular forms
• Initially, plants were found in marine environments or moist environments near ocean shores
• Plants colonized drier environments 500 million years ago
• Plants developed many adaptations to survive in drier environments
• The cuticle, vascular tissues roots and shoots, relationship with fungi and seeds with pollen are all adaptations of plants to thrive in drier environments
• Since colonizing land, about 290,000 species of plants have arose
• The Earth was formed 4550 million years ago
• Photosynthesis appeared in cyanobacteria 3500 million years ago
• The first plastid appeared and plants and red algae diverged 1500 million years ago
• The colonization of land by plants, fungi, then animals occurred 500 million years ago
• All plants have starch as the main energy-storage molecule
• Starch is a polysaccharide (carbohydrate) of glucose residues
• Starch is made of 20% Amylose and 80% Amylopectin
• Sugar is not very reactive and easily metabolized but it absorbs and holds water making it not great for energy storage, starch is the solution because it is easily broken down into sugar
• Chlorophyll b is seen in all plants
• Chlorophyll a is the main photosynthetic molecule and is found in all photosynthetic eukaryotes
• Chlorophyll b is an accessory pigment that passes energy to chlorophyll a
• Chlorophyll b absorbs slightly different wavelengths allowing maximal photosynthesis
• Cellulose is the major component of the cell wall in all plants