BY 124 1st Edition Lecture 5 Outline of Last Lecture Chapter 35I. Plant Tissue Systems II. Plant GrowthIII. Types of Plant Life CyclesIV. Primary GrowthV. Types of Primary Growth VI. Secondary GrowthVII. Leaf AnatomyChapter 36I. Overview of Resource Acquisition and Transport in Vascular PlantsII. Solute TransportIII. Water Transport and MovementIV. Transmembrane RoutesV. Transport from Root Hairs to XylemOutline of Current Lecture Chapter 36I. Transpirational Pull Cohesion-Adhesion MechanismII. Mechanisms of Stomatal Opening and ClosingIII. Movement Through PhloemIV. Sieve TubesChapter 37I. Essential Elements in PlantsII. Cation ExchangeIII. Soil Bacteria and NitrogenIV. Plants That Have Relationships With Another OrganismV. Nutritional Adaptations in PlantsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Current LectureChapter 36 (cont.)I. How does water get to top of tree once in xylem and phloem? a. Used to think it was root pressure i. Only possible for small plants ii. Hydathodes- allows for “guttation” or the formation of droplets in margins of veins (Figure 36.11)b. Answer for trees: Transpritational Pull Cohesion-Adhesion Mechanism allows for water to move up trees (Figure 36.13)1. Cohesion – attracted to each other (H+ bonds)2. Adhesion – anything charged is attracted to anything else charged (water and walls of plant)ii. Water column must be continuous. You can’t put it back together once it is completely broken1. If slightly damaged, cells can merge with others to make a new pathII. Mechanisms of Stomatal Opening and Closing (Figure 36.15)a. Chloroplast in stomata (Figure 36.14)b. If plenty of water, stomata will openi. The stomata know this because guard cells are full of water and can lose waterc. If not a lot of water, stomata close because guard cells become flaccidd. Ways that things move through stomatai. Deals with potassium ion in stomata1. Chlorine ion follows potassium chargeii. Relates to proton pumps and ATPe. If not enough carbon dioxide, stomata will close i. Why? Because carbon dioxide is needed for photosynthesisf. Plants have a circadian rhythm i. Normal rhythm is to open stomata every ~12 hrsg. Allowing water to leave through stomata not only pulls water up xylem but allows for evaporative cooling to keep plant from overheating.III. Ways Things Move Through Phloem (Figure 36.17)a. Movement of sugar from leaves (mesophyll) through everything until it gets to sieve tubes (phloem)i. Diffusionii. If you have active transport then you can get more out of it 1. Takes ATP/energy to use proton pumpa. Sucrose is neutral so cannot use gradientsIV. Sieve Tubesi. Sink is where sugar (sucrose) ends upa. Make sugar in leaves by photosynthesisb. Proton pumps load sugar into phloemc. Water moves in form xylem by concentration gradient and causes sugar from source (leaf) to fall/move down phloem (to roots)i. Stored in sink cellsd. Water down at bottom of plant follows new concentration gradient and moves back into xylem to be drawn up to start cycle againChapter 37: Soil and Plant Nutrition**Remember that plants are photoautotrophs – make own food by photosynthesisI. Essential Elements in Plants (Table 37.1)a. **nutrients come in as ions because they will be cofactors for enzymesb. Macronutrients – stuff you need a lot of i. Nitrogen – cannot be taken up from the atmosphere/through atmospheric nitrogen1. Need nitrate (NO3-) or ammonium (NH4+)ii. Magnesium – every molecule of chlorophyll needs itc. Micronutrientsi. Iron – cytochromesII. Cation Exchange (Figure 37.3)a. Plants use cation exchange to absorb nutrients from soil and wateri. Two protons (H+) move out and one Calcium ion (Ca2+) moves in from soil because it is attracted to negative charge of root hairii. Excess nutrients stored in vacuole and xylemIII. Soil Bacteria and Nitrogen (Figure 37.10)a. Nitrogen fixing bacteria nitrogen and turn it into NH3 i. Or ammonifying bacteria take organic material (humus) and turn it into NH3b. Takes H+ from soil and turns NH3 into NH4+i. Can go straight into plant at this point but sometimes it continues with following stepsc. Can take NH4+ and use nitrifying bacteria to make NO3- (nitrate)i. Denitrifying bacteria turns NO3- back to N2 (atmospheric N)d. Rhizobium – nitrogen-fixing bacteriai. Cyanobacteria will also fix nitrogenii. Soybean plants will take bacteria into roots (symbiotic)1. When soybeans uptake these bacteria, cells become bacteroidsIV. Plants That Have Relationships With Another Organisma. Mycorrhizae – “fungus root”i. Fungus are heterotrophs so take sugar from other plantsii. Fungus = good at breaking down stuff1. Wood2. Get phosphorous for plantsa. Water tooiii. Fungus has growth factors that help plant roots grow as their roots growiv. ProtectionV. Nutritional Adaptations in Plants (Figure 37.15)a. Epiphytes – “upon a plant” (ex. Staghorn Fern)i. Don’t take anything. Just there because it needs the supportb. Photosynthetic parasites (ex. Mistletoe)i. Can survive on its own but takes from the tree because it “is lazy”c. Nonphotosynthetic parasite (ex. Dodder)d. Nonphotosynthetic parasite of mycorrhizae (ex. Indian