Bio 209 Lab Prelims PDF, A.Y. 2024-2025

BIO 209 LAB Prelims | First Semester | A.Y. 2024-2025 - O2- required to perform - CO2- produced by it Outline...

BIO 209 LAB Prelims | First Semester | A.Y. 2024-2025 - O2- required to perform - CO2- produced by it Outline - Respiratory and Circulatory systems work together to I. Homeostasis bring O2 to cells and get rid of CO2 II. Osmosis Process III. Photosynthesis 1. A person inhales O2, which then diffuses in the air sac of the lungs into the blood. 2. O2-carrying blood is pumped by the heart to blood vessels near all body cells, 3. O2 diffuses from blood to cells which is the used for Homeostasis respiration. Refers to the maintenance of the constant internal 4. CO2 is produced by respiration and moves through conditions the blood to the lungs where it is exhaled Animal organs and organ systems constantly adjust Negative Feedback Regulation to internal and external changes through a process called homeostasis ("steady state") - Ensure that O2 is delivered to meet cells’ needs for Homeostasis means to maintain dynamic respiration equilibrium in the body. - Enough CO2 is removed to prevent harmful effects. - Dynamic because it is constantly adjusting - Note: increased CO2 blood levels stimulate increased to the changes that the body's systems breathing. encounter. Procedure - Equilibrium because body functions are STEP exercise kept within specific ranges. Even an animal Resting pulse rate taken that is apparently inactive is maintaining Step exercise performed at a constant rate for 3 this homeostatic equilibrium. minutes The goal of homeostasis is the maintenance of Pulse rate immediately taken after exercise equilibrium around a point or value called a set Recovery time, or when the pulse rate after exercise point. matches resting pulse rate, recorded - While there are normal fluctuations from Simulation: Healthy male (37 yrs, 74.8 kg) the set point, the body’s systems will usually Exercise for 40 mins, exercise power at 0, 50, 100, 150, attempt to go back to this point. 200, 150, 100, 50, 0 Exercise for 50 mins, constant at 200 Recovery time Recovery time refers to the time period between the end of a bout of exercise and the subsequent return to a resting or recovered state, as well as specific physiological processes states occurring after exercise that are distinct from the physiology of either the exercising or the resting states. Although exercise drives beneficial cardiovascular adaptations associated with routine physical activity, it is during the recovery period in which these adaptations take place. Negative Feedback Recovery of the cardiovascular system after exercise Change in a regulated variable triggers a response, occurs across a period of minutes to hours. reversing the initial change - Variability exists within the recovery process Bring regulated variable back to setpoint due to training status (trained vs. untrained), Play an important role in maintaining homeostasis factors of fatigue and a person’s ability to Example deal with physical, emotional and psychological stressors Main constant body temperature Positive Feedback - Change in a variable triggers a response that causes more change in the same direction - Useful when there is an advantage in making a rapid change Example Facilitate the rapid formation of a platelet plug Cellular Respiration - Carried out by cells to make ATP - ATP- provides energy for cells  BIO 209 LAB Prelims | First Semester | A.Y. 2024-2025 Other Notes Osmosis is crucial for maintaining cellular functions and homeostasis. Water potential determines the direction of water flow in plant cells. The interaction between osmotic potential and pressure potential defines the overall water potential in cells. Photosynthesis Photosynthesis is essential to all life on earth; both plants and animals depend on it. The energy of sunlight is “captured” to energize electrons, whose energy is then stored in the covalent bonds of sugar molecules. The ability to capture light energy is due to pigments. As a pigment, chlorophyll can be identified by the Osmosis specific pattern of wavelengths it absorbs from visible Osmosis is the movement of water across a light; this is termed the absorption spectrum. semipermeable membrane from an area of low Chlorophyll reflects green light but absorbs blue and solute concentration (or low osmotic pressure) to an red wavelengths. area of high solute concentration (or high osmotic Many photosynthetic organisms have a mixture of pressure). pigments, and by using these pigments, the Osmotic Pressure organism can absorb energy from a wider range of Osmotic Pressure (V): wavelengths. Osmotic pressure is the pressure required to prevent Photosynthesis has two phases, the light-dependent osmosis. It can be calculated using the equation: and Light-Independent phase V=R⋅T⋅cs Light-Dependent Phase where: Energy Conversion: R = gas constant (8.32 J/mol K) T = temperature (in Kelvin) ○ Energy from sunlight is absorbed and cs= concentration of solute (in mol/L) converted into chemical energy stored in the form of ATP and NADPH. Photon Absorption: Water Movement Water moves from low osmotic pressure to high ○ Sunlight strikes pigments (such as osmotic pressure. chlorophyll) in the photosystems, causing Cell Types Relative to Solution: excitation of the pigments. This means that - Isoosmotic: Cell and solution have the same electrons in the pigments are boosted to osmotic pressure. higher energy levels. - Hypoosmotic: Cell has lower osmotic Electron Transport Chain (ETC): pressure than the solution (water moves into ○ The excited electrons are transferred the cell). through the electron transport chain (ETC), - Hyperosmotic: Cell has higher osmotic which is a series of proteins embedded in pressure than the solution (water moves out the thylakoid membrane. of the cell, causing plasmolysis). ○ As the electrons move through the ETC, ATP Tonicity vs. Osmolarity is produced via ATP Synthase (using the Tonicity (iso-, hypo-, hypertonic) does not always energy from a proton gradient). directly relate to osmolarity. ○ In the light-dependent phase, both ATP and Example: An isoosmotic sucrose solution is isotonic to an NADPH are produced, and these molecules animal cell but hypotonic to a plant cell. will be used later in the light-independent Water Potential (Ψ): (Calvin) phase for sugar synthesis. Water potential (Ψ) measures the energy state of water and includes: Important Notes: - Osmotic Potential (Ψs): Contribution by solutes, always negative (decreases water The light-dependent phase is the first stage of potential). photosynthesis, where sunlight is captured and - Pressure Potential (Ψp): Can be positive, stored in chemical form. negative, or zero, but usually positive in turgid plant cells (contributes to turgor pressure).  BIO 209 LAB Prelims | First Semester | A.Y. 2024-2025 The main products of this phase are ATP (energy) Some examples: and NADPH (electron carrier), which are used to - β-Carotene – red-orange pigment; most power the Calvin Cycle. common form of carotene in plants - α-Carotene – second-most common form of Light-Independent Phase carotene Xanthophylls – yellow pigments; unlike carotenes, Also called the Dark Reaction Phase because light is they have oxygen. no longer needed but carbon dioxide is Some examples: Carbon dioxide serves as the source of Carbon which - Lutein – appears yellow in low will be pieced together to form concentrations; orange-red in higher conc. glyceraldehyde-3-phosphate, which will form glucose - Zeaxanthin gives corn (Zea mays) its yellow and eventually starch. color) Starch The general term where plant pigment is stored is Plant carbohydrate called Plastids Monomer is glucose Solubility of Plant Pigments Plant carbohydrate is stored as starch Chlorophyll and other pigments are lipids, thus with varying Light Reaction Goal degree of solubility in To create ATP it needs energy coming from light and solvents: passive transport from the electron transport chain Acetone is the main solvent used in extraction, but Pigments. around 90% acetone is required, because more than 10% water in the solvent would not fully extract Chlorophyll chlorophyll a and β-carotene It has its own wavelengths which can absorb light, Ethanol can also be used to extract pigments Other cannot be absorbed so it will be reflected Water, however, is highly polar and would not extract Chlorophyll a and B reflects green light but absorbs the lipid pigments. red and blue Absorption Spectrum Other pigments Plant pigments absorb light at certain wavelengths Certain wavelengths that cannot be absorbed by To determine which wavelengths are absorbed, a chlorophyll can be absorbed by others spectrophotometer can be used Plants can get a lot of energy from different Spectrophotometer emits light, which is then wavelengths. absorbed by the pigment Parasitic Plants Spectrophotometer gives out readings in terms of Do not photosynthesize absorbance (abs), or how much light is absorbed: Get inside the vascular system of a plant and steal - Smaller absorbance means less light is nutrients absorbed Still classified as plants - Absorbance can also measure Plant Pigments concentration, so how much of the pigment is in the sample will affect absorbance value Chlorophyll readings, but this can be amended by using Chlorophyll a and b are mixed prenyl lipids: they possess an a range of wavelengths (such as from isoprenoid phytyl chain which is bound to a nonisoprenoid 400-700 nm) and then comparing porphyrin ring system. absorbances across that spectrum Chlorophyll a – blue-green; has a Phytyl ring, a Shorter wavelength means higher energy hydrophobic tail Chlorophyll b – pale green; Porphyrin ring possess magnesium in the middle of hydrocarbons - Plant pigment is soluble in acetone. Used in Chromatography to get the pigment - Most plant pigments are hydrophobic. - Plant pigment is not soluble in water - Ethanol is less polar than water. Pigment is comparatively soluble in it. - Chlorophyll is the most dominant pigment because they are efficient in absorbing different wavelengths Carotenoids Carotenoids as tetraterpenoids are simple or pure prenyl lipids, the carbon skeleton of which is made up solely of isoprenoid units. There are two groups of carotenoids: - Carotenes – oxygen-free (hydrocarbons); they are named after carrot.  BIO 209 LAB Prelims | First Semester | A.Y. 2024-2025 Stroma: The fluid-filled space inside the chloroplast, Chromatography solvent is different used to extract separated from the thylakoid space by a phospholipid pigment. Its purpose is to dissolve pigments and bilayer (similar to the structure in mitochondria). bring it higher on the chromatography paper. 1. Photon Strikes Photosystem I: Light (photon) hits The lightest pigment will travel the fastest, the Photosystem I, specifically its reaction center, causing heaviest will stay at the bottom excitation of the pigments. A reason why a pigment cant be easily seen is the 2. Excitation of Electrons: When the photon strikes the plant does not have enough of that pigment reaction center, pigments become excited, moving Absorption Spectrum: A graph that shows how up to a higher energy level. much light a pigment absorbs at different 3. Electron Transport: wavelengths. It helps identify which wavelengths of ○ Excited electrons are transferred to the first light are best for photosynthesis, based on the part of the electron transport chain (ETC) to pigment's ability to absorb light effectively a protein called Q or Plastoquinone (PQ). ○ Simultaneously, water is split (into oxygen, protons, and electrons). The oxygen is released as a by-product, and a proton gradient forms across the membrane. 4. Proton Gradient: This gradient powers ATP and NADPH production. 5. Synthesis: ATP and NADPH are synthesized, which are then used to produce G3P (Glyceraldehyde-3-phosphate). Enzymes involved: ○ NADP Reductase (to form NADPH) ○ ATP Synthase (to form ATP) Electron Transport Chain (ETC) Components Blue and red light will be the best for growing plants which means a lot of lights to make photosynthesis faster 1. Photosystem II: Splits water and transports the resulting electrons to Q (Plastoquinone). Production of Oxygen 2. Q (Plastoquinone): Carries electrons to the b6-f Subject: Myriophyllum complex. Reagent: NaHCO3 3. PC (Plastocyanin): Carries electrons to Photosystem Bubbles that emerge are oxygen I. Oxygen comes from light reaction 4. Photosystem I: Passes electrons through Fd Samples closer to the light had more bubbles as they (Ferredoxin), which then transfers electrons to NADP receive more light Reductase, forming NADPH. Pondweeds have a specialized tissue called Water Splitting: aerenchyma which is filled with gas. ○ Non-polar oxygen exits through the This enables the pondweed fronds to float, bringing stomata. them closer to the surface of the water. ○ Protons (H+) can’t exit easily due to their - Gases also diffuse through the air spaces in ionic nature, so they move through ATP the aerenchyma, allowing oxygen produced Synthase, generating energy to produce by photosynthesis to diffuse down to the ATP. roots which are buried in anoxic soil. This allows cells in the roots to respire. Gases produced in the roots will also diffuse up through the Calvin-Benson Cycle air spaces in the aerenchyma. When the stem is turned upside down and cut under This is the light-independent phase of the level of the water, gas can escape from the air photosynthesis, meaning it doesn’t require light and spaces and bubble up to the surface can happen even in the evening. Plant parts that are cut outside of water will produce air bubbles; the xylem will explode. It is called CO₂ Fixation: cavitation destroying vascular bundles. Photosynthetic Electron Transport Chain and CO₂ is fixed (attached) to a five-carbon molecule ATP Synthesis called Ribulose 1,5-bisphosphate (RuBP) using the enzyme RuBisCO. Photosystem I: It appears later in the process but This forms an unstable 6-carbon compound, which was the first to be discovered. quickly splits into two molecules of Reaction Center: Contains chlorophylls, 3-phosphoglycerate (3-PGA). beta-carotenes, and other pigments.  BIO 209 LAB Prelims | First Semester | A.Y. 2024-2025 The process is similar to the Krebs cycle in that a key molecule (RuBP) is regenerated to allow the cycle to continue. Energy Source: ATP and NADPH produced in the light-dependent reactions provide the energy for the Calvin Cycle. These energy carriers help drive the production of sugars. The Cycle: After CO₂ is fixed to RuBP, forming a 6-carbon compound, it splits into 3-PGA molecules. In the Reduction Phase, ATP and NADPH are used to convert 3-PGA into Glyceraldehyde 3-phosphate (G3P), a 3-carbon sugar. G3P is a precursor to glucose, but it takes two molecules of G3P to eventually form one glucose molecule. The Regeneration Phase ensures that RuBP is regenerated, so the cycle can continue accepting CO₂. Key Phases of the Calvin Cycle: Carboxylation (CO₂ Fixation): ○ RuBisCO, the most abundant enzyme, catalyzes the attachment of CO₂ to RuBP to form the unstable 6-carbon compound, which splits into two 3-PGA molecules. Reduction Phase: ○ ATP and NADPH are used to convert 3-PGA into G3P (Glyceraldehyde 3-phosphate), a 3-carbon molecule. ○ G3P can also exist as dihydroxyacetone phosphate (the ketone form). Regeneration Phase: ○ Most of the cycle is dedicated to regenerating RuBP, so more CO₂ can be accepted. ○ Although G3P is produced, most of it goes back to regenerate RuBP, and only a small portion is used to produce sugars. ○ It takes 3 molecules of CO₂ to make 1 G3P that can be used for glucose production. Important Notes: RuBP + CO₂ = 6-carbon compound, but this compound quickly splits into two 3-PGA molecules. ATP and NADPH are essential for the reduction of 3-PGA into G3P and for regenerating RuBP. Two G3P molecules are needed to eventually form one glucose molecule.