stages of cellular respiration for students.pptx

cellular respiration for medical students

1. Victoria university Kampala-Uganda PHYSIOLOGY 1 PRESENTATION BY GROUP .4 KUTEGANA SEMUTEWO VU-BPC-2307-0245-DAY NOURELDEIN ABDALLA VU-BPC-2307-0889-DAY ISABIRYE ANDERSON VU-BPC-2307-0715-DAY NTEGE ABUDALLAH VU-BPC-2307-1132-DAY

2. QUESTIONS ARE: 13. Explain the concepts of cellular respiration and its stages. 14.What are mechanisms of cellular secretion? 15. Describe the role of the lysosomes in cellular digestion and recycling. 16. Discuss the physiological consequences of oxidative stress at cellular levels.

3. 13. E xplain the concepts of cellular respiration and its stages: Cellular respiration is the process through which cells produce energy in form of ATP by breaking down glucose or other organic molecules. There are two forms of cellular respiration and that's aerobic respiration and anaerobic respiration. Aerobic respiration requires oxygen to take place whereas anaerobic respiration occur in absence of oxygen. It occurs in the mitochondria of eukaryotic cells and the cytoplasm of prokaryotic cells. It can be divided into three major stages that’s glycolysis, citric acid cycle and the electron transport system.

4. 14. What are mechanisms of cellular secretion? 1. Exocytosis:  is the process of moving materials from within a cell to the exterior of the cell. This process requires energy and is therefore a type of active transport. Exocytosis is an important process of plan and animal cell as it performs the opposite function of endocytosis. In endocytosis, substances that are external to a cell are brought into the cell. In exocytosis, membrane-bound vesicles containing cellular molecules are transported to the cell membrane. The vesicles fuse with the cell membrane and expel their contents to the exterior of the cell. The process of exocytosis can be summarized in a few steps . It involves the fusion of secretory vesicles with the cell's plasma membrane, releasing the contents outside the cell.

5. 14. What are mechanisms of cellular secretion? 2. Constitutive secretion: In this mechanism, cells continuously and constitutively secrete certain substances. The secretory vesicles fuse with the plasma membrane spontaneously, leading to the continuous release of the contents into the extracellular space. 3. Regulated secretion: The secretory vesicles are stored within the cell until a specific signal triggers their fusion with the plasma membrane and release of the contents. 4. Membrane transporters : Some substances are secreted across the cell membrane through specific transporters. These transporters actively move the substances from inside the cell to the extracellular space.

6. 15. Describe the role of the lysosomes in cellular digestion and recycling : Lysosomes are membrane-bound organelles found in eukaryotic cells that play a crucial role in cellular digestion and recycling, also known as autophagy. The main function of lysosomes is to break down various molecules, including proteins, lipids, carbohydrates, and nucleic acids. They contain digestive enzymes called acid hydrolases, which are active at an acidic ph. These enzymes are responsible for breaking down and digesting complex molecules into simpler forms that can be used by the cell.

7. Describe the role of the lysosomes in cellular digestion and recycling: Lysosomes are involved in intracellular digestion, where they fuse with endocytic vesicles, phagosomes, or autophagosomes (vesicles that enclose damaged organelles or unwanted cytoplasmic components). The enzymes within lysosomes then break down the contents of these vesicles, allowing the cell to obtain nutrients or eliminate waste. Aside from cellular digestion , lysosomes also play a crucial role in recycling cellular components through a process called autophagy. During autophagy, damaged or malfunctioning organelles, excess proteins, or unnecessary cytoplasmic components are engulfed by autophagosomes. These autophagosomes then fuse with lysosomes, and the contents are broken down by the lysosomal enzymes. The breakdown products are subsequently released back into the cytoplasm, where they can be reused by the cell to synthesize new molecules or generate energy.

8. 16 . Discuss the physiological consequences of oxidative stress on cellular level : Oxidative stress is the imbalance between production of reactive oxygen species and the ability of the cell to neutralize them with antioxidants Reactive oxygen species include superoxideradicals, hydroxide ions, hydroxyl ions ,peroxide ions etc. Effects: It causes cell senescence since it oxides cell chromosomes and affects chromosomes ends which contain telomere and as a result this causes cell aging since the cell loses ability to divide by mitosis or meiosis It causes apoptosis and neurosis which cell programmed death hence leading to death of normal healthy cells.

9. Continuation It leads to mutations since it leads to modifications in the DNA and hence mutations cause abnormal cell functioning which leads to cell cancers Oxidative stress leads t o inflammation since it activates pro-inflammatory pathways leading to production of inflammatory cytokines hence causes autoimmune disorders It causes mitochondria dysfunction since Reactive Oxygen species are produced during integrin formation hence this overwhelms the cell metabolically due to lack of ATP to carry out catabolism and anabolism.