1 PRE-LABS WEEK 3 Name of students: Nguyen Giang Yen Tho Student’s ID: BTFTIU18118 1. What are autotrophs and heterotrophs? Give each one example. - Autotrophs and Heterotrophs are living organisms obtain chemical energy in one of two ways. Differences between Autotrophs and Heterotrophs: AUTOTROPHS: o Food is chemical energy stored in carbohydrates. o Food provides both the energy to do work and the carbon to build bodies. o Transform sunlight to make food, which is called a Photosynthesis process. o The beginning of the food chain. Most of the animals along with the heterotrophs depend on this to live their life-cycles and balance the food chain. Seen as the producers of the food chain For instance: Plants are the most obvious autotrophs, Fungis, Bacteria. HETEROTROPHS: o Cannot make their own food, so they must eat or absorb it o Seen as consumers of the food chain. o Only autotrophs can transform that ultimate, solar source into the chemical energy in food that powers life. o Diverse, help to balance the biodiversity, maintain the ecologicalbalance. For instance: animals, humans, etc. 2. What is “photosynthesis”? How many stages are there in the photosynthesis? Describe. o Photosynthesis is the process by which plants, some bacteria and some protistants use the energy from sunlight to produce glucose from carbon dioxide and water. This glucose can be converted into pyruvate which releases adenosine triphosphate (ATP) by cellular respiration. Oxygen is also formed. o It is a process of two stages. - The Light dependent reactions, a light-dependent series of reactions which occur in the grana, and require the direct energy of light to make energy-carrier molecules that are used in the second process: light energy is trapped by chlorophyll to make ATP (photophosphorylation) at the same time water is split into oxygen, hydrogen ions and free electrons: 2H2O 4H+ + O2 + 4e- (photolysis) 2 PRE-LABS WEEK 3 Name of students: Nguyen Giang Yen Tho Student’s ID: BTFTIU18118 the electrons then react with a carrier molecule nicotinamide adenine dinucleotide phosphate (NADP), changing it from its oxidised state (NADP+) to its reduced state (NADPH): NADP+ + 2e- + 2H+ - NADPH + H+ The light-independent reactions, a light-independent series of reactions which occur in the stroma of the chloroplasts, when the products of the light reaction, ATP and NADPH, are used to make carbohydrates from carbon dioxide (reduction); initially glyceraldehyde 3-phosphate (a 3-carbon atom molecule) is formed. 3. Where is the chlorophyll distributed in plants and animals? o Chlorophyll is a complex molecule. PLANTS: o Several modifications of chlorophyll occur among plants and other photosynthetic organisms. o All photosynthetic organisms have chlorophyll a. Accessory pigments absorb energy that chlorophyll a does not absorb. o Chlorophyll is found in the thylakoid sacs of the chloroplast. ANIMALS: o There is no Chlorophyll found in animals. 4. What is the function of chlorophyll? o Chlorophyll is a green photosynthetic pigment found in plants, algae, and cyanobacteria. PRE-LABS WEEK 3 3 Name of students: Nguyen Giang Yen Tho Student’s ID: BTFTIU18118 o Chlorophyll absorbs mostly in the blue and to a lesser extent red portions of the electromagnetic spectrum, hence its intense green color. o Green substance in producers that traps light energy from the sun, which is then used to combine carbon dioxide and water into sugars in the process of photosynthesis Chlorophyll is vital for photosynthesis, which helps plants get energy from light. o Chlorophyll molecules are specifically arranged in and around pigment protein complexes called photosystems, which are embedded in the thylakoid membranes of chloroplasts. 5. Define the terms “transpiration” and “respiration”. What is the difference between them? RESPIRATION: o Respiration is the process by which plants convert carbon dioxide to oxygen as a part of photosynthesis. o Plants process carbon dioxide to produce energy, so this process is often considered as part of the carbon cycle and the mitigation of global warming due to atmospheric carbon dioxide. o Since plants use carbon dioxide as part of photosynthesis, they remove that carbon dioxide from the atmosphere. TRANSPIRATION: o Transpiration is the process of water movement inside of the plant's system. This means water drawn from roots and leaves, up through the stem and cells of the plant. This water movement distributes minerals and is essential to the plant's survival. 6. What are stomata and guardcells? Describe their distribution on the leaf. o Guard cells are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata. - These adjust the size of the opening by opening or closing. To open a guard cell, protons (hydrogen ions, H+) are pumped into the guard cells. Water enters them, the cells get hard, and they push open. PRE-LABS WEEK 3 4 Name of students: Nguyen Giang Yen Tho Student’s ID: BTFTIU18118 o Stomata open and close to allow the intake of carbon dioxide and the release of oxygen. It's very vital that they do this because this is the very oxygen that we ourselves need to breathe. - They are mostly found on the under-surface of plant leaves. In a stoma, there is the chloroplast, a cell wall, a vacuole and a cell nucleus.