Results for "stomata"

Stomata and guard cells

16. Opening and closing stomata

Gas exchange and stomatal physiology- LECTURE 1

stomata

Photosystems and Role of Stomata and Guard Cells

Stomata Lab+Exercise Lab

Unit 3 (Gas Exchange): Introducing Plant Parts and Stomata's Functions

Biological Methods - Stomata and cuticles

Biology Practicals: Distribution of stomata on the two surfaces of a leaf

Bio LK Stomata, Blattaufbau, Schatten-und Sonnenblätter, Farbstoffe der Blätter, Besondere Pflanzen

Key Concepts: Cell Theory, Cell Structure & Function, Prokaryotic vs. Eukaryotic, Cell Membrane, Microscopes, Passive vs. Active Transport, Diffusion, Osmosis, Energy (Potential vs. Kinetic), Photosynthesis & Cell Respiration (Aerobic vs. Anaerobic), Fermentation (Lactic Acid & Alcoholic) 1. Describe one similarity and one difference between the two terms in each of the following pairs: a. Eukaryote, prokaryote Eukaryote: Has a membrane-bound nucleus in the cell Prokaryote: No nucleus, DNA free-floating in the cell, can have flagellum Both: have cell membranes, have DNA, have ribosomes b. Cell wall, cell membrane Cell wall: rigid, not as flexible, more selective (harder for things to pass through) Cell membrane: fluid, flexible, selectively permeable Both: enclose cell, facilitate what goes in/out of cell c. Diffusion, facilitated diffusion Diffusion: movement of particles from high to low concentration Facilitated diffusion: movement of particles through channel proteins Both: are passive transport (no energy required), particles move from HIGH to LOW 2. Describe the structure of a phospholipid bilayer. There are 2 layers of phospholipids (consisting of hydrophilic heads and hydrophobic tails) 3. Explain the following diagram using the terms: diffusion, cell membrane, low concentration, energy, high concentration. The water molecules are moving across the cell membrane to reach a state of equilibrium. The molecules move from HIGH to LOW concentration, so they move downwards across the membrane. This is an example of diffusion, or passive transport - this does not require energy because it is fueled by the difference in concentrations. 4a. What is the microscope magnification of the eye piece? scanning? low power? high power? ● Eye piece = 10x ● Scanning = 4x ● Low power = 10x ● High power = 40x b. If you were looking at an onion cell using the high power lens, what is the TOTAL MAGNIFICATION at which you are looking at the cell? High power = 40x Eye piece = 10x 40 x 10 = 400x Your total magnification would be 400x using the higher power objective lens. 5. Identify the difference between hypertonic, isotonic, and hypotonic solutions: A = isotonic B = hypotonic C = hypertonic 6. How is active transport different from diffusion and facilitated diffusion? ● Active Transport = requires energy, molecules are forced AGAINST the gradient from LOW to HIGH concentration ● Diffusion = does not require energy, molecules move from HIGH to low concentration ● Facilitated diffusion = does not require energy, molecules move from HIGH to low concentration, but it requires the help of channel proteins (typically larger molecules) 7. Explain what is happening in the following picture. This is an example of ENDOCYTOSIS (Active Transport) - there is a chemical/nutrients being taken into the cell when it’s engulfed by the cell membrane (becomes a vesicle). 8. What is the difference between potential and kinetic energy? Give an example of each. a. Poyential energy - stored energy; e.g,glucose, a ball at the topof ahill b. Kinetic energy - energy of motion e.g., a car onthe freeway 9. Write out the full chemical reaction for PHOTOSYNTHESIS. What organelle is responsible for this? Chloroplast 10. Write out the full chemical reaction for CELL RESPIRATION. What organelle is responsible for this? Mitochondria 11. If we are at 400X magnification (field diameter is 450 micrometers), and there are 10 cells that fit across the diameter of what we’re seeing, what is the estimated size of ONE cell? 450 nanometers / 10 cells = 45 nanometers per cell 12. What is the role of the stomata? What is the role of the guard cells? Stomata role isgas exchange to let oxygen and carbondioxide pass through, as needed for key processes such as photosynthesis and cellular respiration. Guard cells arepairs of cells that surround the stomata and controlgas exchange by regulatingthe openingand closure of stomata. 13. What would cause guard cells to swell and open stomata? What would cause guard cells to shrink and close stomata? → Whentheplanthas anexcess of water, theguard cells swell and create anopeningfor the exchange ofgas → Whentheplanthas a lack of water, theguard cells shrink and close the openingfor the exchange ofgas 14. In fermentation, what relationship exists between the amount of available sugar and amount of carbon dioxide produced? → As more sugar is available, there will be more fermentationthathappens, and more carbondioxideproduced → There is a direct relationshipbetweenthose two factors 15. List the # of ATP produced by each of the following: Glycolysis = 2 ATP Krebs = 2 ATP ElectronTransport = 34 ATP 16. Explain one example of lactic acid fermentation. Explain one example of alcoholic fermentation. a. Lactic acid fermentation- heating milk and combiningit withtwo live bacteria cultures, resultinginthe bacteria breakingdownthe sugars in milk and releasinglactic acid (distinct tart/sour taste) b. Alcoholic fermentation- yeast and bacteria beingadded to tea and fruit (sugar), resultinginkombucha withethanol and carbondioxide bubbles

BL1004- stomata

(CIE A2 Biology) ABA + stomatal closures

(CIE A2 Biology) Guard cells + stomatal openings/closures

(CIE A2 Biology) Stomata basics

Cell and Structures Cell vs. Viruses • Cells: Simplest living structures capable of performing all life functions independently. • Viruses: Non-living entities requiring a host cell to replicate and survive. Microscopes • Light Microscope: Uses visible light, magnifies up to 1,000x; resolution limited by wavelength of light. • SEM (Scanning Electron Microscope): Creates detailed 3D images of surfaces; does not show internal structures. • TEM (Transmission Electron Microscope): Produces high-resolution images of internal cellular structures. Magnification and Resolution • Magnification: Enlarges an object’s appearance. • Resolution: Measures the clarity of an image by distinguishing two points as separate. Robert Hooke • Coined the term "cells" after observing cork under a microscope. • Published his findings in Micrographia (1665), advancing the study of cells. Cytology and Biochemistry • Cytology: The study of cell structure and function. • Biochemistry: The study of chemical processes and substances within organisms. Cell Fractionation • A laboratory technique to break apart cells and isolate organelles for detailed study. Size Limitations of Cells • Smaller cells have a higher surface area-to-volume ratio, which is essential for efficient exchange of materials. Prokaryotes vs. Eukaryotes • Prokaryotes: No nucleus or membrane-bound organelles; simpler and smaller (e.g., bacteria). • Eukaryotes: Have a nucleus and membrane-bound organelles; larger and more complex. Cell Structures and Functions • Nucleus: Stores genetic material (DNA). • Plasma Membrane: Protects the cell; regulates material exchange. • Cytosol: Fluid portion of the cytoplasm where cellular processes occur. • Microvilli: Increases surface area for absorption in some animal cells. • Cytoskeleton: ◦ Microfilaments (actin): Provides structural support. ◦ Microtubules: Involved in transport and motility. • Animal Cell-Specific Structures: ◦ Desmosomes: Anchor cells together. ◦ Gap Junctions: Channels that allow communication between cells. ◦ Tight Junctions: Create a watertight seal between cells. • Extracellular Matrix (ECM): Nonliving material outside cells, providing structural and biochemical support. • Plant Cell-Specific Structures: ◦ Plasmodesmata: Channels connecting cytoplasm between plant cells. Cellular Respiration Definition • Process of extracting energy from glucose to produce ATP, the cell's main energy currency. ATP • Made by the enzyme ATP synthase, powered by hydrogen ion (H⁺) movement across the inner mitochondrial membrane. Three Stages of Respiration 1 Glycolysis (Cytoplasm): ◦ Reactants: Glucose. ◦ Products: 2 Pyruvate, 2 ATP (net), and NADH. 2 Krebs Cycle (Mitochondrial Matrix): ◦ Reactant: Acetyl CoA. ◦ Products: CO₂, NADH, FADH₂, and 2 ATP. 3 Electron Transport Chain (ETC) (Inner Mitochondrial Membrane): ◦ Reactants: NADH and FADH₂ (electron carriers). ◦ Products: Water and ~32-34 ATP. Key Points • No oxygen = no Krebs cycle or ETC; only 2 ATP are produced via glycolysis. • Fermentation occurs in anaerobic conditions: ◦ Converts pyruvate into lactic acid (in animals) or ethanol (in yeast). Photosynthesis Overview • Process where plants convert light energy into chemical energy (sugars). • Formula: CO2+H2O→O2+G3PCO_2 + H_2O \rightarrow O_2 + G3PCO2​+H2​O→O2​+G3P. Key Concepts 1 Light Reactions (Thylakoid Membranes): ◦ Products: ATP and NADPH (used in the Calvin Cycle). ◦ Oxygen is produced by Photosystem II. 2 Calvin Cycle (Stroma): ◦ Uses ATP and NADPH to fix carbon dioxide into G3P (a sugar precursor). Photosystems • Photosystem II: Produces oxygen and ATP. • Photosystem I: Produces NADPH. Adaptations • C4 Pathway: Spatial separation of steps to avoid photorespiration. • CAM Pathway: Temporal separation, stomata open at night to reduce water loss. Mitosis and Meiosis Mitosis • Division of a eukaryotic somatic (non-reproductive) cell into two identical diploid cells. • Phases: 1 Prophase: Chromosomes condense; spindle forms. 2 Metaphase: Chromosomes align at the cell's equator. 3 Anaphase: Sister chromatids separate. 4 Telophase: Nuclear envelopes reform. 5 Cytokinesis: Cytoplasm splits into two cells. Meiosis • Specialized cell division in germ cells (ovaries/testes) to produce gametes. • Key Features: ◦ Two divisions produce four genetically unique haploid cells. ◦ Crossing over occurs during Prophase I for genetic diversity. Binary Fission • A simple form of cell division in prokaryotes producing two identical cells. Genetics • Haploid: Single set of chromosomes (e.g., gametes). • Diploid: Two sets of chromosomes (e.g., somatic cells). • Punnett Squares and Pedigrees: Tools to predict genetic inheritance. Cell and Structures Cell vs. Viruses • Cells: Simplest living structures capable of performing all life functions independently. • Viruses: Non-living entities requiring a host cell to replicate and survive. Microscopes • Light Microscope: Uses visible light, magnifies up to 1,000x; resolution limited by wavelength of light. • SEM (Scanning Electron Microscope): Creates detailed 3D images of surfaces; does not show internal structures. • TEM (Transmission Electron Microscope): Produces high-resolution images of internal cellular structures. Magnification and Resolution • Magnification: Enlarges an object’s appearance. • Resolution: Measures the clarity of an image by distinguishing two points as separate. Robert Hooke • Coined the term "cells" after observing cork under a microscope. • Published his findings in Micrographia (1665), advancing the study of cells. Cytology and Biochemistry • Cytology: The study of cell structure and function. • Biochemistry: The study of chemical processes and substances within organisms. Cell Fractionation • A laboratory technique to break apart cells and isolate organelles for detailed study. Size Limitations of Cells • Smaller cells have a higher surface area-to-volume ratio, which is essential for efficient exchange of materials. Prokaryotes vs. Eukaryotes • Prokaryotes: No nucleus or membrane-bound organelles; simpler and smaller (e.g., bacteria). • Eukaryotes: Have a nucleus and membrane-bound organelles; larger and more complex. Cell Structures and Functions • Nucleus: Stores genetic material (DNA). • Plasma Membrane: Protects the cell; regulates material exchange. • Cytosol: Fluid portion of the cytoplasm where cellular processes occur. • Microvilli: Increases surface area for absorption in some animal cells. • Cytoskeleton: ◦ Microfilaments (actin): Provides structural support. ◦ Microtubules: Involved in transport and motility. • Animal Cell-Specific Structures: ◦ Desmosomes: Anchor cells together. ◦ Gap Junctions: Channels that allow communication between cells. ◦ Tight Junctions: Create a watertight seal between cells. • Extracellular Matrix (ECM): Nonliving material outside cells, providing structural and biochemical support. • Plant Cell-Specific Structures: ◦ Plasmodesmata: Channels connecting cytoplasm between plant cells. Cellular Respiration Definition • Process of extracting energy from glucose to produce ATP, the cell's main energy currency. ATP • Made by the enzyme ATP synthase, powered by hydrogen ion (H⁺) movement across the inner mitochondrial membrane. Three Stages of Respiration 1 Glycolysis (Cytoplasm): ◦ Reactants: Glucose. ◦ Products: 2 Pyruvate, 2 ATP (net), and NADH. 2 Krebs Cycle (Mitochondrial Matrix): ◦ Reactant: Acetyl CoA. ◦ Products: CO₂, NADH, FADH₂, and 2 ATP. 3 Electron Transport Chain (ETC) (Inner Mitochondrial Membrane): ◦ Reactants: NADH and FADH₂ (electron carriers). ◦ Products: Water and ~32-34 ATP. Key Points • No oxygen = no Krebs cycle or ETC; only 2 ATP are produced via glycolysis. • Fermentation occurs in anaerobic conditions: ◦ Converts pyruvate into lactic acid (in animals) or ethanol (in yeast). Photosynthesis Overview • Process where plants convert light energy into chemical energy (sugars). • Formula: CO2+H2O→O2+G3PCO_2 + H_2O \rightarrow O_2 + G3PCO2​+H2​O→O2​+G3P. Key Concepts 1 Light Reactions (Thylakoid Membranes): ◦ Products: ATP and NADPH (used in the Calvin Cycle). ◦ Oxygen is produced by Photosystem II. 2 Calvin Cycle (Stroma): ◦ Uses ATP and NADPH to fix carbon dioxide into G3P (a sugar precursor). Photosystems • Photosystem II: Produces oxygen and ATP. • Photosystem I: Produces NADPH. Adaptations • C4 Pathway: Spatial separation of steps to avoid photorespiration. • CAM Pathway: Temporal separation, stomata open at night to reduce water loss. Mitosis and Meiosis Mitosis • Division of a eukaryotic somatic (non-reproductive) cell into two identical diploid cells. • Phases: 1 Prophase: Chromosomes condense; spindle forms. 2 Metaphase: Chromosomes align at the cell's equator. 3 Anaphase: Sister chromatids separate. 4 Telophase: Nuclear envelopes reform. 5 Cytokinesis: Cytoplasm splits into two cells. Meiosis • Specialized cell division in germ cells (ovaries/testes) to produce gametes. • Key Features: ◦ Two divisions produce four genetically unique haploid cells. ◦ Crossing over occurs during Prophase I for genetic diversity. Binary Fission • A simple form of cell division in prokaryotes producing two identical cells. Genetics • Haploid: Single set of chromosomes (e.g., gametes). • Diploid: Two sets of chromosomes (e.g., somatic cells). • Punnett Squares and Pedigrees: Tools to predict genetic inheritance.

Here are the answers to your biology questions: 1. Definitions: * Metabolism: The sum total of all chemical reactions that occur within a living organism. * Catabolism: The breakdown of complex molecules into simpler ones, releasing energy. * Anabolism: The synthesis of complex molecules from simpler ones, requiring energy input. * Endergonic Reaction: A reaction that requires an input of energy to proceed. * Exergonic Reaction: A reaction that releases energy. 2. Role of Enzymes in Metabolism: Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy. They bind to specific substrates, forming an enzyme-substrate complex, and catalyze the reaction. This allows metabolic processes to occur at rates compatible with life. 3. Enzyme Activity: * Activation Energy: The minimum amount of energy required for a reaction to occur. * Catalyst: A substance that speeds up a chemical reaction without being consumed in the process. * Active Site: The specific region on an enzyme where the substrate binds. * Denaturation: The loss of an enzyme's shape and function, often due to extreme temperature or pH. * Substrate: The molecule upon which an enzyme acts. * Enzyme-Substrate Complex: A temporary complex formed when an enzyme binds to its substrate. * Suffix -ase: Commonly used to denote enzymes, such as sucrase, protease, and lipase. 4. Oxidation-Reduction Reactions in Cellular Respiration: In cellular respiration, oxidation-reduction reactions involve the transfer of electrons and hydrogen ions. Oxidation is the loss of electrons (and often hydrogen atoms), while reduction is the gain of electrons (and often hydrogen atoms). Energy is released during these reactions and is used to produce ATP. 5. Balanced Equation for Cellular Respiration: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP) 6. Structure of a Mitochondrion: * Outer Membrane: Encloses the mitochondrion. * Inner Membrane: Folded into cristae, increasing surface area for ATP production. * Intermembrane Space: The space between the outer and inner membranes. * Matrix: The fluid-filled space inside the inner membrane, containing enzymes for the citric acid cycle. 7. Glycolysis: Glycolysis is the breakdown of glucose into pyruvate. It occurs in the cytoplasm and produces 2 ATP, 2 NADH, and 2 pyruvate molecules. 8. Citric Acid Cycle: The citric acid cycle, also known as the Krebs cycle, occurs in the mitochondrial matrix. It completely oxidizes pyruvate, producing 2 ATP, 6 NADH, and 2 FADH₂ molecules per glucose molecule. 9. Electron Transport Chain and Oxidative Phosphorylation: The electron transport chain is a series of protein complexes embedded in the inner mitochondrial membrane. Electrons from NADH and FADH₂ are transferred through the chain, releasing energy that is used to pump protons into the intermembrane space. The resulting proton gradient drives ATP synthesis through ATP synthase. 10. ATP and NADH Production: * Glycolysis: 2 ATP, 2 NADH * Citric Acid Cycle: 2 ATP, 6 NADH, 2 FADH₂ * Electron Transport Chain: ~32 ATP (from NADH and FADH₂) 11. Structure and Function of a Dicot Leaf: Dicot leaves are typically broad and flat, with a network of veins. They have a waxy cuticle to prevent water loss, stomata for gas exchange, and mesophyll cells containing chloroplasts for photosynthesis. 12. Structure of a Chloroplast: * Thylakoid: A flattened, disc-shaped sac. * Thylakoid Membrane: The membrane surrounding the thylakoid. * Thylakoid Space: The interior of the thylakoid. * Stroma: The fluid-filled space outside the thylakoids. * Grana: Stacks of thylakoids. 13. Site of Light-Dependent and Light-Independent Reactions: * Light-Dependent Reactions: Thylakoid membrane * Light-Independent Reactions (Calvin Cycle): Stroma 14. Balanced Equation for Photosynthesis: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂ * Carbon (C) from CO₂ is incorporated into glucose. * Hydrogen (H) from water (H₂O) is incorporated into glucose. * Oxygen (O) from water is released as O₂. 15. Dual Nature of Light: Light exhibits both wave-like and particle-like properties. As a wave, it has a wavelength and frequency. As a particle, it consists of photons, discrete packets of energy. 16. Light Reactions: Light energy is absorbed by pigments in photosystems I and II, exciting electrons. These electrons are transferred through a series of electron carriers, generating ATP and NADPH. Water is split, releasing oxygen as a byproduct. 17. Calvin Cycle: The Calvin cycle uses ATP and NADPH from the light reactions to fix CO₂ from the atmosphere. CO₂ is incorporated into RuBP, forming 3-PGA. 3-PGA is reduced to G3P, which can be used to synthesize glucose or regenerate RuBP. 18. Role of Photosynthetic Pigments: Photosynthetic pigments, such as chlorophyll a, chlorophyll b, and carotenoids, absorb light energy and transfer it to the reaction center of photosystems. 19. Role of Photosystems: Photosystems I and II are protein complexes containing pigments and electron carriers. They absorb light energy and use it to excite electrons, initiating the electron transport chain. 20. Phases of the Calvin Cycle: * Carbon Fixation: CO₂ is fixed to RuBP, forming 3-PGA. * Reduction: 3-PGA is reduced to G3P using ATP and NADPH. * Regeneration of RuBP: G3P is used to regenerate RuBP, allowing the cycle to continue. 21. ATP, NADPH, and CO₂ Requirements: * To produce 1 G3P molecule: 9 ATP, 6 NADPH, and 3 CO₂ * To produce 1 glucose molecule: 18 ATP, 12 NADPH, and 6 CO₂ I

BIOL220 Transport: Regulation of Stomata

18) Transpiration and Stomata

Stomata counts