BSCI124 Exam 1 Guide Lecture 1 Introduction to Science Plants What is Science Science is a technique a way of seeking principles about the world Scientists collect data facts to test these principles Plant body is divided into 2 parts shoot grows above ground stem leaves root below ground Lecture 2 The Cell Cell is made of 4 important molecules 1 Carbohydrates sugars starches cellulose monosaccharide glucose fructose ribose disaccharide sucrose maltose lactose polysaccharide starch cellulose functions energy storage structure cell walls 2 Lipids fats oils waxes made from two building blocks glycerol molecule fatty acids phospholipids have hydrophilic head water loving and hydrophobic tail water hating functions part of cell membrane high energy food 3 Proteins amino acids made up of amino acids 20 types control what passes through membrane building blocks of cells 4 Nucleic Acids DNA RNA basic unit is nucleotide sugar phosphate nitrogenous base nucleic acids are long chains of nucleotides DNA RNA ATP is nucleotide compound is energy currency in cell Functions info storage DNA energy carrier ATP The Cell Two Types of Cells prokaryotic lack organelles eukaryotic multicellular have organelles Plant vs Animal Plants have cell walls chloroplasts plasmodesmata vacuoles Cell wall made of cellulose protects supports cell Primary wall formed early outermost layer Secondary deposited on the inside between wall membrane o o o Middle lamella glues adjacent walls together Plasmodesmata allows movement of materials from cell to cell Cytoskeleton made of microfilaments microtubules help in mitosis elongation Plant Cell Organelles Chloroplasts produce sugars from CO2 H20 light photosynthesis Nucleus contains genetic info chromosomes DNA proteins Nucleolus where ribosomes are made Mitochondria provides energy to cell location of respiration Vacuole stores watery solution of sugars salts acids ex Orange lemon slices Ribosomes side for protein synthesis Endoplasmic Reticulum ER network of folded membranes throughout cytoplasm Smooth ER lacks ribosomes transports proteins o o Rough ER has ribosomes for protein synthesis o Golgi apparatus modifies proteins lipids from ER UPS of the cell Lecture 3 Plant Anatomy Physiology Plant Tissue Types 1 Dermal Tissue epidermis outermost later of cells skin stems leaves epidermis has cuticle waxy layer to prevent water loss 2 Vascular Tissue xylem transports water up from root dead cells phloem carries sugars from leaves to roots living cells 3 Ground Tissue makes up bulk of plant functions metabolism storage support Plant Organs 1 Roots anchorage water absorption water nutrient transportation cortex endodermis is innermost layer casparian strip waxy strip in endodermis that helps to control uptake of minerals into the xylem a b 2 Stems support leaves conduct water sugars throughout plant a Epidermis provides protection cuticle wax prevents water loss trichomes hairs release oils b Vascular cambium location in middle of vascular bundle between xylem phloem c Annual rings xylem formed by vascular cambium during one growing season 3 Leaves where photosynthesis occurs a Blade flat expanded area Petiole connect blade to stem b Epidermis transparent for light waxy cuticle protects against drying stomata allow gas exchange c Veins vascular tissue of leaves composed of xylem phloem d Mesophyll middle of leaf palisade parenchyma have chloroplasts spongy parenchyma for gas exchange Plant Water Transport Transpiration Cohesion Theory evaporation of water in leaves generates sucking force that pulls water molecules to surface Sugar translocation sugars made in leaf Mesophyll cells diffuse to phloem in vascular bundles companion cells load dissolved sugars into phloem using ATP 1 2 3 water moves into cells with high sugar concentration 4 osmotic water flow generates hydraulic pressure that moves sugars through plant Plant Hormones produced by plants effective at low concentrations 1 Auxins cell growth involved in gravitropism moves plant toward light photo tropism 2 Gibberellins stem elongation 3 Cytokinins cell division 4 Abscisic Acid seed dormancy stomata closing 5 Ethylene fruit ripening Lecture 4 Photosynthesis Respiration Photosynthesis plants use light energy to organic compounds sugar from nonorganic compounds CO2 H2O Properties of Light light moves in waves photons visible light occurs in colors plants absorb bed red reflect green Chloroplast football shape double membrane stroma thylakoid inside stroma grana stacks lumen inside thylakoid Light Reactions occur in thylakoid water split into oxygen and H light generates ATP NADPH Carbon Dark Reactions do not require light occur in stroma use ATP NADPH to make carbohydrate Calvin Cycle CO2 enters cycle RUBISCO catalyzes first reaction of CO2 into sugar Photosynthesis Summary light energy absorbed by chlorophyll a light converted into chemical energy CO2 H2O produce glucose and O2 Light reactions occur in thylakoids ATP NADPH are formed water is split into O2 photons Carbon Reactions occur in stroma Calvin Cycle fixes CO2 to produce glucose Cellular Respiration making energy from food available in the cell occurs in 3 stages 1 Glycolysis splitting of glucose in cytoplasm 2 ATP generated 2 Krebs Cycle energy of glucose is harvest as 2 ATP in mitochondria 3 Electron Transport System 32 more ATP are generated in mitochondria Energy the ability to do work Newton s 2nd Law 10 of energy remains with each transfer through the food chain Food Chain producers are base of food chain plants primary plants secondary carnivores decomposers fungi Lecture 5 DNA RNA Proteins DNA deoxyribonucleic acid contains all info necessary to make new organisms double helix DNA is a polymer of nucleotides each nucleotide composed of phosphate sugar nitrogenous base 4 kinds of bases Purine adenine guanine Pyrimidine thymine cytosine Replication in nucleus DNA strand becomes a template proper base pairs are assembled nucleotides make a new strand that is identical to old Bonds A T is a double C G is a stronger triple bond separated with heat RNA ribonucleic acid single stranded less stable than DNA Differences between DNA RNA sugar ribose deoxyribose nucleotide thymine uracyl structure Central Dogma DNA transcription RNA translation protein Transcription making an RNA copy mRNA from DNA in nucleus mRNA carries message about which protein to make nucleotide sequences are the same except uracyl mRNA is synthesized RNA polymerase helps bring