Unit 3 Reflection

In this unit we learned about the cell theory, activation energy, membranes, osmosis and diffusion, what a cell does, photosynthesis, and cellular respiration, The most challenging thing about this unit is cellular respiration. There are three steps to cellular respiration. The first step to it is glycoolysis which occurs in the cytoplasm. 2 ATP molecules are produced for one glucose molecule in this step. The second step is the Krebs cycle which converts molecules from glycolysis into 2 ATP, carbon dioxide, and electron carrying molecules. The final step is the electron transport chain which occurs within the inner membrane of mitochondria. It uses oxygen, NADH, and FADH2 to convert ADP into ATP. 32 ATP is produced in this step. This whole process produces a total of 36 ATP, 6 carbon dioxide, and 6 water. Cellular respiration is the process of cells braking down glucose into energy. Photosynthesis is where plants produce glucose and oxygen using sunlight and carbon dioxide. Autotrophs carry out photosynthesis and can be macroscopic or microscopic. They can be multicellular of unicellular. Mesophyll cells are a collection of cells containing chloroplasts. A chloroplast is an organelle containing stroma and grana. Stroma is the space inside chloroplasts and grana is a stack of thylakoids. Thylakoids are membranes that contain chlorophyll. A light dependent reaction occurs in thylakoids of grana. Light is absorbed and energy is transferred between molecules by the electron transport chain. It produces NADPH and ATP. Water is split which releases oxygen and pumping H+ ions into the thylakoid membrane. ATP synthase uses H+ movement to produce ATP. ATP synthase facilitates diffusioin of H+ from high to low concentration. As H+ moves from thylakoid to stroma, ATP is produced. In a light independent reaction, it produces sugar from carbon dioxide using ATP and NADPH from light reactions. The calvin cycle rotates 6 times to produce 1 glucose molecule. I learned a lot from this unit but there is still a lot to learn about biology. I learned a lot about cellular respiration and how photosynthesis works.