Adaptation in biology refers to changes organisms make to survive in their environment.
Example: Caribou, a type of deer, possess cells with unsaturated fatty acids to aid survival in cold, snowy conditions.
All energy in the universe already exists; it can either be useful or not.
The focus is on converting energy into a usable form, essential for life processes.
Metabolic pathways refer to the series of chemical reactions that convert energy into forms that can be stored and later used by the organism.
Energy stored as larger molecules can be utilized by breaking them apart when needed.
Gibbs Free Energy (ΔG): Represents the energy available to perform work.
If ΔG < 0: Reaction is exergonic, energy is released.
Exergonic reactions typically do work, such as moving molecules across cell membranes.
If ΔG > 0: Reaction is endergonic, energy is stored in products.
Endergonic requires energy input for reactions that build larger molecules.
Enzymes serve to lower the activation energy required for a reaction, speeding up the process.
Their shape creates an optimal environment for reactions to occur faster.
Understanding enzyme function is crucial.
Metabolism alternates between releasing energy (exergonic) and storing energy (endergonic).
This balance allows organisms to manage their energy needs effectively through metabolic pathways.
Next Topics: Connection to photosynthesis and cellular respiration.
Photosynthesis synthesizes glucose, using various reactions that illustrate the principles discussed in this chapter.
The study spans from chapter 4 (cell structure) through chapter 5 (cell membranes and transport mechanisms).
Chapter 4 covers the parts of the cell, including:
Cell membrane: Semipermeable barrier controlling what enters and exits the cell.
Golgi apparatus: Modifies, sorts, and packages proteins.
Endoplasmic reticulum (ER): Network of membranes involved in protein and lipid synthesis.
Smooth ER: Synthesizes lipids and detoxifies certain chemicals.
Chapter 5 emphasizes the cell membrane, passive transport methods including:
Diffusion: Movement of molecules from high to low concentration.
Facilitated diffusion: Process of passive transport aided by specific proteins.