Cellular Respiration in Harvesting Chemical Energy

Cellular Respiration in Harvesting Chemical Energy

• Cellular Respiration: the process by which cells convert glucose into energy in the form of ATP (adenosine triphosphate)
• Three stages:
  1. Glycolysis: breaks down glucose into pyruvate, producing a small amount of ATP and NADH
  2. Citric Acid Cycle (Krebs Cycle): converts pyruvate into ATP, NADH, and FADH2
  3. Oxidative Phosphorylation: uses energy from NADH and FADH2 to generate most of the ATP
• Types of Cellular Respiration:
  • Aerobic Respiration: occurs in the presence of oxygen, produces a net gain of 36-38 ATP
  • Anaerobic Respiration: occurs in the absence of oxygen, produces a net gain of 2 ATP

Introduction to Biological Concepts

• Biology: the study of life and living organisms
• Levels of Organization:
  • Molecules: basic building blocks of life (e.g. DNA, proteins, carbohydrates)
  • Organelles: specialized structures within cells (e.g. mitochondria, ribosomes)
  • Cells: basic units of life
  • Tissues: groups of similar cells
  • Organs: structures composed of multiple tissues
  • Organ Systems: groups of organs working together
  • Organism: an individual living thing
• Biological Molecules:
  • Carbohydrates: provide energy and structure (e.g. sugars, starches)
  • Proteins: perform various functions (e.g. enzymes, hormones, structural proteins)
  • Lipids: provide energy and structure (e.g. fats, oils)
  • Nucleic Acids: contain genetic information (e.g. DNA, RNA)

Cell Division and Mitosis

• Cell Division: the process by which a cell becomes two daughter cells
• Types of Cell Division:
  • Mitosis: results in two daughter cells genetically identical to the parent cell
  • Meiosis: results in four daughter cells with half the number of chromosomes as the parent cell
• Stages of Mitosis:
  1. Interphase: cell grows and prepares for cell division
  2. Prophase: chromatin condenses, and the nuclear envelope breaks down
  3. Metaphase: chromosomes line up at the center of the cell
  4. Anaphase: sister chromatids separate
  5. Telophase: nuclear envelope reforms, and chromosomes uncoil
  6. Cytokinesis: cytoplasm divides, and the cell splits into two daughter cells

Cellular Respiration

• Cellular respiration is the process by which cells convert glucose into energy in the form of ATP (adenosine triphosphate)
• The process involves three stages: Glycolysis, Citric Acid Cycle (Krebs Cycle), and Oxidative Phosphorylation
• Glycolysis breaks down glucose into pyruvate, producing a small amount of ATP and NADH
• Citric Acid Cycle (Krebs Cycle) converts pyruvate into ATP, NADH, and FADH2
• Oxidative Phosphorylation uses energy from NADH and FADH2 to generate most of the ATP
• There are two types of cellular respiration: Aerobic Respiration and Anaerobic Respiration
• Aerobic Respiration occurs in the presence of oxygen and produces a net gain of 36-38 ATP
• Anaerobic Respiration occurs in the absence of oxygen and produces a net gain of 2 ATP

Introduction to Biological Concepts

• Biology is the study of life and living organisms
• The levels of organization in biology are: Molecules, Organelles, Cells, Tissues, Organs, Organ Systems, and Organism
• Molecules are the basic building blocks of life, including DNA, proteins, and carbohydrates
• Organelles are specialized structures within cells, such as mitochondria and ribosomes
• Cells are the basic units of life
• Tissues are groups of similar cells
• Organs are structures composed of multiple tissues
• Organ Systems are groups of organs working together
• Organism is an individual living thing
• Biological molecules include carbohydrates, proteins, lipids, and nucleic acids
• Carbohydrates provide energy and structure, such as sugars and starches
• Proteins perform various functions, such as enzymes, hormones, and structural proteins
• Lipids provide energy and structure, such as fats and oils
• Nucleic acids contain genetic information, such as DNA and RNA

Cell Division and Mitosis

• Cell division is the process by which a cell becomes two daughter cells
• There are two types of cell division: Mitosis and Meiosis
• Mitosis results in two daughter cells genetically identical to the parent cell
• Meiosis results in four daughter cells with half the number of chromosomes as the parent cell
• The stages of Mitosis are: Interphase, Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis
• During Interphase, the cell grows and prepares for cell division
• During Prophase, chromatin condenses, and the nuclear envelope breaks down
• During Metaphase, chromosomes line up at the center of the cell
• During Anaphase, sister chromatids separate
• During Telophase, the nuclear envelope reforms, and chromosomes uncoil
• During Cytokinesis, the cytoplasm divides, and the cell splits into two daughter cells

Cellular Respiration

• Cellular respiration is the process by which cells generate energy from glucose to fuel their activities

Overview of Cellular Respiration

• Involves three stages: glycolysis, citric acid cycle, and oxidative phosphorylation
• Breaks down glucose (C6H12O6) to produce ATP (adenosine triphosphate), NADH, and FADH2
• ATP is the energy currency of the cell, providing energy for various cellular activities

Stage 1: Glycolysis

• Occurs in the cytosol
• Converts glucose into pyruvate (C3H4O3), producing 2 ATP and 2 NADH
• Net gain of 2 ATP

Stage 2: Citric Acid Cycle (Krebs Cycle)

• Occurs in the mitochondria
• Converts pyruvate into Acetyl-CoA, which enters the citric acid cycle
• Produces 2 ATP, 6 NADH, and 2 FADH2
• Net gain of 2 ATP

Stage 3: Oxidative Phosphorylation

• Occurs in the mitochondria
• Electron transport chain uses energy from NADH and FADH2 to pump protons across the inner mitochondrial membrane
• Proton gradient drives the production of ATP through chemiosmosis
• Net gain of 32-34 ATP

Efficiency of Cellular Respiration

• Theoretical maximum yield of ATP from glucose is 36-38 ATP
• Actual yield is around 32-34 ATP due to energy losses during the process
• Remaining energy is lost as heat, maintaining the body's thermal homeostasis