BIO 171 Module 2 Study Guide: Latest Updated
Enzymes
● Role in Metabolism: Facilitate biochemical reactions in cells.
● Nature: Proteins or groups of proteins.
● Function: Catalyze (speed up) chemical reactions.
● Reusability: Not consumed during the reaction; can be used repeatedly.
● Specificity and Regulation:
○ Cofactor: Small chemical component, often metal ions.
○ Assistance: Help enzymes during catalysis.
○ Regulation:
■ Without cofactor: Enzymes are inactive.
■ With cofactor: Enzymes are active.
● Microorganisms and Energy Production
○ Energy Production: Microorganisms break down complex nutrients into smaller, useful
subunits to produce energy.
○ Enzymatic Breakdown:
■ Proteins: Broken down into amino acids.
■ Lipids: Broken down into glycerol and fatty acids.
■ Polysaccharides: Broken down into monosaccharides.
○ Cellular Assembly: Cells must also build necessary components for survival.
○ Metabolic Processes:
■ Catabolism: Breaking down larger molecules into energy sources.
■ Anabolism: Building up or biosynthesis of macromolecules from smaller units
into larger complexes.
■ Usage: Common during growth and repair phases of the cell.
○ Energy Requirement:
■ Both catabolic and anabolic processes require significant energy.
■ Enzymes increase the rate of specific chemical reactions to reduce energy
consumption and time.
○ Necessity of Enzymes: Without enzymes, reactions would take too long and consume
too much energy, leading to cell death.
○ Fundamental Need: Cells require energy to function and sustain life.
● Adenosine Triphosphate (ATP)
○ Role: Most widely used form of energy in cells.
○ Transformation:
, ■ ATP to ADP: Removal of a phosphate group from ATP forms ADP.
■ ADP to ATP: ADP can accept a phosphate group to become ATP.
○ Energy Transfer:
■ Catabolic Reactions: ATP donates phosphate groups, transferring energy.
■ Anabolic Reactions: Energy is used for building up processes.
○ Cellular Function: Donation and acceptance of phosphate groups fuel
necessary biochemical reactions.
● Microbial ATP Production and Characterization
○ Energy Sources:
■ Phototrophs: Generate ATP from ADP using light energy.
■ Chemotrophs: Generate ATP from existing chemicals in the environment.
■ Organotrophs: Remove electrons from organic molecules (e.g., glucose).
■ Lithotrophs: Remove electrons from inorganic molecules (e.g.,
elemental sulfur).
○ Carbon Sources:
■ Heterotrophs: Derive carbon from organic molecules (e.g., sugars).
■ Autotrophs: Derive carbon from inorganic molecules (e.g., CO2).
○ Combined Classification: Microorganisms can be classified based on their energy,
electron, and carbon sources (e.g., chemoorganoheterotrophs utilize glucose for all
three).
● Formation of ATP
○ Phosphorylation Processes:
■ Photophosphorylation:
■ Energy Source: Light energy.
■ Mechanism: Powers the formation of ATP from ADP.
■ Substrate-level Phosphorylation:
■ Mechanism: Phosphoryl group of a chemical compound is transferred
directly to ADP.
■ Donor: Phosphorylated reactive intermediate.
■ Oxidative Phosphorylation:
■ Users: Chemotrophs.
■ Mechanism: Energy from chemical oxidation of nutrients reforms ATP.
■ Location: Mitochondria in eukaryotic cells.
■ Efficiency: Highly efficient process.
○ Glucose Catabolism and ATP Production
■ Glucose Catabolism:
■ Importance: Key metabolic pathway for ATP production in
microorganisms.
■ Yield: Complete catabolism of glucose (C6H12O6) yields up to 38 ATP.
■ Transitions: Involves three distinct steps. ■
Glycolysis:
■ Initiation: Breakdown of a single molecule of glucose.
■ Reactants:
■ Glucose.
■ Two molecules of the coenzyme nicotinamide adenine
dinucleotide (NAD).
Enzymes
● Role in Metabolism: Facilitate biochemical reactions in cells.
● Nature: Proteins or groups of proteins.
● Function: Catalyze (speed up) chemical reactions.
● Reusability: Not consumed during the reaction; can be used repeatedly.
● Specificity and Regulation:
○ Cofactor: Small chemical component, often metal ions.
○ Assistance: Help enzymes during catalysis.
○ Regulation:
■ Without cofactor: Enzymes are inactive.
■ With cofactor: Enzymes are active.
● Microorganisms and Energy Production
○ Energy Production: Microorganisms break down complex nutrients into smaller, useful
subunits to produce energy.
○ Enzymatic Breakdown:
■ Proteins: Broken down into amino acids.
■ Lipids: Broken down into glycerol and fatty acids.
■ Polysaccharides: Broken down into monosaccharides.
○ Cellular Assembly: Cells must also build necessary components for survival.
○ Metabolic Processes:
■ Catabolism: Breaking down larger molecules into energy sources.
■ Anabolism: Building up or biosynthesis of macromolecules from smaller units
into larger complexes.
■ Usage: Common during growth and repair phases of the cell.
○ Energy Requirement:
■ Both catabolic and anabolic processes require significant energy.
■ Enzymes increase the rate of specific chemical reactions to reduce energy
consumption and time.
○ Necessity of Enzymes: Without enzymes, reactions would take too long and consume
too much energy, leading to cell death.
○ Fundamental Need: Cells require energy to function and sustain life.
● Adenosine Triphosphate (ATP)
○ Role: Most widely used form of energy in cells.
○ Transformation:
, ■ ATP to ADP: Removal of a phosphate group from ATP forms ADP.
■ ADP to ATP: ADP can accept a phosphate group to become ATP.
○ Energy Transfer:
■ Catabolic Reactions: ATP donates phosphate groups, transferring energy.
■ Anabolic Reactions: Energy is used for building up processes.
○ Cellular Function: Donation and acceptance of phosphate groups fuel
necessary biochemical reactions.
● Microbial ATP Production and Characterization
○ Energy Sources:
■ Phototrophs: Generate ATP from ADP using light energy.
■ Chemotrophs: Generate ATP from existing chemicals in the environment.
■ Organotrophs: Remove electrons from organic molecules (e.g., glucose).
■ Lithotrophs: Remove electrons from inorganic molecules (e.g.,
elemental sulfur).
○ Carbon Sources:
■ Heterotrophs: Derive carbon from organic molecules (e.g., sugars).
■ Autotrophs: Derive carbon from inorganic molecules (e.g., CO2).
○ Combined Classification: Microorganisms can be classified based on their energy,
electron, and carbon sources (e.g., chemoorganoheterotrophs utilize glucose for all
three).
● Formation of ATP
○ Phosphorylation Processes:
■ Photophosphorylation:
■ Energy Source: Light energy.
■ Mechanism: Powers the formation of ATP from ADP.
■ Substrate-level Phosphorylation:
■ Mechanism: Phosphoryl group of a chemical compound is transferred
directly to ADP.
■ Donor: Phosphorylated reactive intermediate.
■ Oxidative Phosphorylation:
■ Users: Chemotrophs.
■ Mechanism: Energy from chemical oxidation of nutrients reforms ATP.
■ Location: Mitochondria in eukaryotic cells.
■ Efficiency: Highly efficient process.
○ Glucose Catabolism and ATP Production
■ Glucose Catabolism:
■ Importance: Key metabolic pathway for ATP production in
microorganisms.
■ Yield: Complete catabolism of glucose (C6H12O6) yields up to 38 ATP.
■ Transitions: Involves three distinct steps. ■
Glycolysis:
■ Initiation: Breakdown of a single molecule of glucose.
■ Reactants:
■ Glucose.
■ Two molecules of the coenzyme nicotinamide adenine
dinucleotide (NAD).
