Bio Assessment 03/06/2025

Cellular Respiration

• Definition: Cellular respiration is the process by which cells convert glucose and oxygen into energy, water, and carbon dioxide.

• Organisms: Most organisms perform cellular respiration including animals, plants, fungi, and many microorganisms.

Homeostasis

• Definition: Homeostasis is the ability of an organism to maintain a stable internal environment despite external changes.

• Importance: It is crucial for survival as it helps regulate temperature, pH, hydration, and other vital processes within the organism.

Feedback Mechanisms

• Definition: Feedback mechanisms are processes that use the conditions of one component of a system to regulate the function of another component.

• Positive Feedback Example: During childbirth, the release of oxytocin increases uterine contractions, which in turn stimulates more oxytocin release.

• Negative Feedback Example: Regulation of body temperature; when the body is too hot, mechanisms such as sweating and vasodilation help cool it down.

Anaerobic vs Aerobic Respiration

• Anaerobic Respiration:

  • Conditions: Occurs in the absence of oxygen.

  • Inputs: Glucose.

  • Outputs: Lactic acid (in animals) or alcohol and carbon dioxide (in yeast).

• Aerobic Respiration:

  • Conditions: Occurs in the presence of oxygen.

  • Inputs: Glucose and oxygen.

  • Outputs: Carbon dioxide, water, and a large amount of ATP.

  • Comparison: Aerobic respiration produces more ATP (approximately 36-38 ATP) than anaerobic respiration (2 ATP).

Gas Exchange Model Inputs and Outputs

• Inputs: Glucose (from food), Oxygen (from respiration/atmosphere).

  • Glucose is used to extract energy, while Oxygen is crucial for aerobic respiration.

• Outputs: Carbon dioxide and water (byproducts).

  • Carbon dioxide is released back into the atmosphere, while water can be reused in the body or also released.

ATP Molecule

• Definition: ATP (Adenosine Triphosphate) is the energy currency of the cell, used for various cellular processes.

• Importance: It provides energy for biochemical reactions necessary for life, powering cellular functions and processes.

Food Energy Processing to Make ATP

• Food molecules like carbohydrates (e.g., glucose), fats, and proteins can be processed to make ATP.

• Process: During cellular respiration, these molecules are broken down through glycolysis, the Krebs cycle, and oxidative phosphorylation to produce ATP.

Types of “Food Energy” for ATP Production

• Types: Carbohydrates, fats, and proteins can be used.

• Difference: Carbohydrates are typically the quickest source of energy, while fats yield the most ATP due to their high energy content per molecule.

Regulation of Blood-Glucose Levels

• Regulation: Controlled by hormones like insulin and glucagon; insulin lowers blood glucose levels while glucagon raises them.

• Importance: Maintaining stable blood-glucose levels is vital for providing consistent energy to cells and preventing complications associated with too high or too low blood sugar levels.

Effects of Exercise on Homeostasis

• What Happens: During exercise, there is an increase in heart rate and breathing rate to supply more oxygen and nutrients to muscles.

• Why: Increased demand for energy and nutrient supply requires metabolic adjustments.

• Maintenance of Homeostasis: The body uses feedback mechanisms to keep internal conditions stable, adjusting heart rate, breathing, and blood flow during physical activity.

Role of Veins and Arteries in Homeostasis

• Veins and Arteries: Arteries transport oxygen-rich blood from the heart to the body, while veins return oxygen-poor blood back to the heart.

• Function: Together, they help regulate blood circulation and pressure during rest and during exercise, playing a crucial role in maintaining stable physiological conditions.