Cellular Level of Organization Biology PDF

Chapter 2: Chemical Level of Organization & Chapter 3: Cellular Level of Organization Levels of Organization of the Human Body from Simplest to Most Complex **Chemical level** - simplest level - deals with body's chemistry - Atoms and molecules **Organelle Level** - Molecules wit...

Chapter 2: Chemical Level of Organization & Chapter 3: Cellular Level of Organization Levels of Organization of the Human Body from Simplest to Most Complex **Chemical level** - simplest level - deals with body's chemistry - Atoms and molecules **Organelle Level** - Molecules with together as organelles to preform specific functions - Ex: Mitochondria, ribosomes, and Golgi **Cellular level** - Organelles work together to form the functions of a cell - Trillions of cells **Tissue Level** - Trillions of cells work together to form tissues **Organ level** - different tissues work together to perform specific functions at the organ level - Ex: Stomach, liver, and lung tissue **Systems level** - Organs work together to perform functions such as digestion and respiration Chemical Level  Chemical Level - Water The Human Body is made up of ***[50-75% water]***. Chemical Level -- Acids, Bases, & pH The ***[acid--base balance]*** is very important to the body's ***[homeostasis]***. - Example: the ***[pH of human blood]*** needs to be within the very narrow pH range of ***[7.35 to 7.45]***. - ***[Acidosis:]*** blood pH lower than 7.35; can be fatal. - ***[Alkalosis:]*** blood pH higher than 7.45; can be fatal. [pH & buffer system video](https://www.youtube.com/watch?v=ouhAeCMcTUM) https://www.youtube.com/watch?v=ouhAeCMcTUM Organic Molecules -- Carbohydrates  Organic Molecules -- Lipids  Organic Molecules -- Proteins  Organic Molecules -- Nucleic Acids  [MACROMOLECULES EXPLAINED](https://www.youtube.com/watch?v=V5hhrDFo8Vk) https://www.youtube.com/watch?v=V5hhrDFo8Vk Organelle Level - Specialized, membrane-bound structures of cells - Each organelle has its own function, and together they carry out the necessary cellular functions - Suspended in ***[cytoplasm:]*** - Fluid containing electrolytes, nutrients, wastes and gases  **[Cell (Plasma) Membrane]** Function: - - - ***[Cilia:]*** - [ ***Microvilli:***] - Provide extra surface area to facilitate absorption of extracellular materials **[Nucleus]**  *Structure:* - Contains enzymes, proteins, DNA, and nucleotides surrounded by a double membrane - Controls metabolism, stores and processes genetic information, and controls protein synthesis **[Mitochondria ]** - Double membrane, encloses important metabolic enzymes - Produces 95% of the ATP required by the cell - Carry out cellular respiration and process the energy released to form ATP - Organelle Level: Endoplasmic Reticulum (ER) ***[Rough ER:]*** - Site of protein production ***[Smooth ER:]*** - Site of lipid and carbohydrate production ***[Ribosome]*** - RNA and proteins - Fixed ribosomes -- rough ER - Free ribosomes - cytoplasm Function: Assemble amino acids into proteins ***[Golgi Complex]*** - Stacks of flattened membranes containing chambers - Receives and modifies proteins and lipids produced in the cell - Stores, alters, and packages synthesized products ***[Secretory Vesicles]*** - Carry materials from the Golgi Complex to the cell membrane for export outside the cell ***[Lysosome]*** - Vesicles containing digestive enzymes - Store and isolate enzymes often used for intracellular digestion until they are needed - Breakdown of organic compounds and damaged organelles or pathogens [PARTS OF A CELL SONG](https://www.youtube.com/watch?v=NkC9AiJf7gI&t=1s) https://www.youtube.com/watch?v=NkC9AiJf7gI&t=1s Passive Transport - Moving materials across the cell membrane either into or out of the cell - No energy is required - ***[Example: Filtration in Kidneys]*** - Gravity & blood pressure force wastes out of the bloodstream to form urine in the kidney - No energy is required - Moving materials from an area of high concentration to an area of low concentration until they become equal - 1\. Temperature - 2\. Molecular Weight - 3\. Concentration Gradient - 4\. Membrane Surface Area Speed of Simple Diffusion - Increased temperature = increases the speed - Heat causes the molecules to move faster - Cold causes the molecules to move slower - Heavy proteins move slower - Lighter, smaller molecules (electrolytes, gases) diffuse faster ***[(3) Concentration gradient:]*** - Amount of difference in concentration on either side of the membrane - Greater the difference, the faster the diffusion - Movement occurs until equal on both sides of the membrane - Greater surface area = greater the speed of diffusion (more membrane) ***[Facilitated Diffusion:]*** - Passive transport - Used for molecules that cannot diffuse through the membrane on their own - Need help getting through a channel - ***[Example: Insulin ]*** - Binds to a receptor (shaped specifically for insulin) on the cell's surface - Gated channel opens - Glucose diffuses into the cell from an area of high concentration to an area of low concentration until equal ***[Active transport:]*** - Movement of materials across the cell membrane from areas of low concentration to areas of high concentration - Process goes against the natural trend of diffusion - Requires the cell's usable form of ATP energy - ***[Example:]*** ***[Sodium-potassium pump ]*** - Controls the flow of electricity by controlling the concentration of ions and movement across the cell membrane  - ***[Endocytosis:]*** - Moves materials into the cell in bulk - Large quantities of materials, not individual ions/molecules - ***[Example:]*** - WBC moves close to a foreign particle - Engulfs it with its cell membrane - Fully closes membrane - ***[Exocytosis: ]*** - Moves materials out of the cell in bulk - ***[Example:]*** - Enclosed bacterium moves in the cell - Merges with the cell membrane - Opens to the outside and expels the contents (digested bacterium) https://www.youtube.com/watch?v=OmJwEi9ZuL0 cell transport