Cell Physiology PDF

2] CELL PHYSIOLOGY 1. What are the main functions of cells in the human body? - Cells provide structure for the body’s tissues and organs, ingest nutrients and convert them to energy, perform specialized functions, and contain the body’s hereditary code. 2. What are the two major parts of a typic...

2] CELL PHYSIOLOGY 1. What are the main functions of cells in the human body? - Cells provide structure for the body’s tissues and organs, ingest nutrients and convert them to energy, perform specialized functions, and contain the body’s hereditary code. 2. What are the two major parts of a typical cell? - The nucleus and the cytoplasm. 3. What separates the nucleus from the cytoplasm and the cytoplasm from the surrounding fluids? - The nuclear membrane separates the nucleus from the cytoplasm, and the cell membrane (or plasma membrane) separates the cytoplasm from the surrounding fluids. Composition of Protoplasm 4. What is protoplasm composed of? - Water, electrolytes, proteins, lipids, and carbohydrates. 5. What is the concentration of water in most cells? - 70% to 85%. 6. What are the major ions found in cells and their importance? - Potassium, magnesium, phosphate, sulfate, bicarbonate, sodium, chloride, and calcium. They provide inorganic chemicals for cellular reactions and are necessary for the operation of some cellular control mechanisms. Proteins 7.What are the two types of proteins found in cells and their roles? - Structural proteins and functional proteins. Structural proteins form filaments that provide structure, while functional proteins act as enzymes that catalyze chemical reactions. 8. What are microtubules and their function? - Microtubules are intracellular filaments that form the cytoskeleton of cellular organelles and hold the parts of the cytoplasm and nucleoplasm together..... Lipids 9. What are the primary types of lipids found in cells? - Phospholipids, cholesterol, and triglycerides. 10. What role do phospholipids and cholesterol play in the cell membrane?  - They form the cell membrane and intracellular membrane barriers, determining the permeability of the membrane to water-soluble substances and contributing to the fluidity of the membrane. 11. What is the main function of triglycerides in fat cells? - They serve as the body’s main storehouse of energy-giving nutrients..... Carbohydrates 12. What is the primary role of carbohydrates in cells? - They play a major role in cell nutrition and have structural functions as parts of glycoprotein molecules. 13. How do cells store carbohydrates? - Most cells store carbohydrates in the form of glycogen, an insoluble polymer of glucose..... Cell Membrane Structure 14. What is the basic structure of the cell membrane? - A lipid bilayer composed of phospholipids, sphingolipids, and cholesterol, with embedded proteins. 15. What is the difference between integral and peripheral proteins in the cell membrane? - Integral proteins protrude all the way through the membrane, while peripheral proteins are attached only to one surface of the membrane. 16. What is the glycocalyx and its functions? - The glycocalyx is a loose carbohydrate coat on the cell's outer surface. It provides a negative charge to repel other negatively charged objects, attaches cells to each other, acts as receptors for hormones, and participates in immune reactions..... Organelles 17. What are the key organelles found in the cytoplasm? - Endoplasmic reticulum, Golgi apparatus, mitochondria, lysosomes, and peroxisomes. 18. What is the function of the endoplasmic reticulum (ER)? - It processes molecules made by the cell and transports them to their specific destinations. 19. What is the difference between rough and smooth ER? - Rough ER has ribosomes attached to its surface and synthesizes proteins, while smooth ER lacks ribosomes and is involved in lipid synthesis. 20. What is the role of the Golgi apparatus?  - It processes and packages substances from the ER into lysosomes, secretory vesicles, and other cytoplasmic components.... Detailed Questions.... Water and Ions 21. Why are ions important for cellular functions? - They are necessary for cellular reactions and control mechanisms, such as transmitting electrochemical impulses in nerve and muscle fibers. 22. What role does water play in cellular reactions? - It acts as a solvent for chemical reactions and suspends particles where reactions take place..... Structural and Functional Proteins 23. How do structural proteins contribute to the cell's structure? - They form filaments that provide support and organization to cellular components. 24. What is the role of functional proteins within the cell? - They act as enzymes to catalyze specific intracellular chemical reactions..... Lipids and Membrane Structure 25. What characteristic of lipids makes them suitable for forming cellular membranes? - Their solubility in fat solvents and insolubility in water allows them to form barriers that control substance movement in and out of cells. 26. How does cholesterol influence the cell membrane? - It helps determine the membrane's permeability to water-soluble substances and controls its fluidity..... Carbohydrates and Energy Storage 27. Why is glycogen important for cells? - It is a readily available energy source that can be quickly mobilized to meet the cell's energy needs. 28. How do muscle and liver cells differ in their carbohydrate storage compared to other cells? - Muscle cells can store up to 3% of their mass as carbohydrates, and liver cells can store up to 6%, whereas most other cells store about 1%..... Membrane Proteins 29. What functions do integral proteins serve in the cell membrane? - They form channels for water-soluble substances, act as carriers for transport, and serve as receptors for signaling molecules. 30. What are the roles of peripheral proteins in the cell membrane? - They function as enzymes or controllers of substance transport through membrane pores..... Cytoplasm and Organelles 31. What is the cytosol, and what does it contain? - The cytosol is the jelly-like fluid portion of the cytoplasm containing dissolved proteins, electrolytes, and glucose. 32. How do the ribosomes and rough ER work together? - Ribosomes on the rough ER synthesize new proteins that are processed and transported by the ER. 33. What are the functions of the smooth ER? - It synthesizes lipid substances and performs other cell processes facilitated by its enzymes. 34. How does the Golgi apparatus process substances from the ER? - Substances are transported in vesicles from the ER to the Golgi apparatus, where they are modified, sorted, and packaged for specific destinations. These questions and answers comprehensively cover the provided text's content, ensuring a thorough understanding of cellular structure and function.