Unit 3 Reflection

     Unit 3 was about cells and their functions. Macromolecules serve as the building blocks for life because they make up different parts of the cell and they all serve different purposes. The cell theory states that all things are composed of cells, a cell is the basic unit of life, and new cells generate from existing cells. Prokaryotic cells have no nucleus, while eukaryotic cells have a nucleus.

     Membranes and their unique characteristics are so essential for life because they all have different functions that are necessary for life. The nuclear membrane holds DNA in the nucleus and allows RNA to leave through the pores. The lysosome holds enzymes for recycling proteins. The endoplasmic reticulum (ER) holds proteins as they are finished off and holds lipids as they are made. The vesicles export molecules in and out of the cell. The golgi apparatus packages and releases finished proteins, lipids, and hormones. The membranes in chloroplasts and mitochondria creates carbohydrates through the process of photosynthesis, and breaks down carbohydrates through the process of cellular respiration. The cell membrane holds all cell contents inside and protects from the outside environment. The cell membrane also controls the passage of molecules inside.

       Semipermeable membranes allow some molecules to cross the membrane, while others can not. Passive transports require no effort or energy. Active transports use energy to bring rare but highly needed molecules into the cell. Diffusion is the movement of small molecules from high to low concentration through the lipid bilayer. Proteins that make it possible for large molecules to pass through the membrane through the process of facilitated diffusion. Osmosis is the diffusion of water across selectively permeable membrane. An isotonic solution is when the solute concentration is the same outside and inside the cell. A hypertonic solution is a solute concentration that is greater than that inside the cell. A hypotonic solution is a solute concentration that is less than that inside the cell.
     Cells specialize in making proteins. Mitosis is the process in which one cell reproduces by dividing into two cells. Photosynthesis converts light into chemical energy. A cell creates energy by creating ATP  from glucose to power the cell. The endosymbiotic theory explains how a large cell ingested bacteria and became part of it.
     Photosynthesis is the process in which plants produce glucose and oxygen using sunlight and carbon dioxide. Light dependent reactions occur in the thylakoids of grana. Light independent reactions occur in the stroma.
     Cellular respiration is the process of breaking down glucose into energy. It has 3 stages: glycolysis, krebs cycle, and the electron transport chain. Glycolysis produces two ATP for every one glucose molecule. The Krebs Cycle coverts molecules from glycolysis into two ATP, CO2, Nadh, and FADH2. The electron transport chain uses oxygen, NADH, Fadh2, and converts ATP into ADP. This last stage produces 32 ATP.
     The process of photosynthesis and the process of cellular respiration undo each other. Photosynthesis occurs in the chloroplasts in autotrophs, while cellular respiration occurs in the mitochondria in autotrophs and heterotrophs.
     Overalll, I really enjoyed this unit. I liked learning about photosynthesis and cellular respiration. I had a tough time remembering the function of each organelle in a  cell. I had a fun time looking at cells under a microscope, and I realized how complicated a single cell can be.