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Citric Acid Formation in the Krebs Cycle: Citric acid (also known as citrate) is formed in the Krebs cycle (also known as the citric acid cycle or TCA cycle) when acetyl-CoA, derived from carbohydrates, fats, or proteins through various metabolic pathways, condenses with oxaloacetate. This reaction is catalyzed by the enzyme citrate synthase. The chemical reaction can be summarized as follows:
\[ \text{Acetyl-CoA} + \text{Oxaloacetate} \rightarrow \text{Citrate} + \text{CoA} \]
This reaction marks the first step of the Krebs cycle, initiating a series of reactions that further process citrate to eventually regenerate oxaloacetate.
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Chemical Formula for Lactic Acid Fermentation: The general equation for lactic acid fermentation can be represented as follows:
\[ \text{Glucose} \rightarrow \text{Lactic Acid} + \text{ATP} \]
The chemical formula for lactic acid is C₃H₆O₃. The overall reaction, detailing glucose (C₆H₁₂O₆) being converted to lactic acid and ATP, can be expressed as:
\[ C₆H₁₂O₆ \rightarrow 2 , C₃H₆O₃ + 2 , ATP \]
This process occurs in anaerobic conditions (absence of oxygen) and is common in muscle cells and certain microorganisms.
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Ectotherm Body Temperature Regulation: Ectotherms, or "cold-blooded" animals, regulate their body temperature primarily through behavioral adaptations rather than internal physiological processes. They often rely on external environmental conditions. Some strategies include:
- Basking: Ectotherms seek out sunlight or warm surfaces to raise their body temperature.
- Shade Seeking: They move to shaded areas or burrows to cool down when temperatures become too high.
- Water Availability: Ectotherms may immerse themselves in water to regulate heat.
- Position and Orientation: They adjust their body position relative to heat sources (e.g., sun) to maximize or minimize heat absorption.
By utilizing environmental heat sources, ectotherms can maintain a functional body temperature that supports their physiological processes.