Energy Transformations in Cellular Processes

First Law of Thermodynamics

Energy cannot be created or destroyed.

Kinetic Energy

Energy of motion, like heat from an oven.

Chemical Energy

Energy stored in chemical bonds, like in cake.

Entropy

Measure of disorder in a system.

Endergonic Reaction

Reaction that absorbs energy, requiring input.

Exergonic Reaction

Reaction that releases energy, producing work.

Condensation Reaction

Process forming bonds by releasing water.

ATP

Adenosine triphosphate, energy currency of cells.

Activation Energy

Minimum energy needed for a reaction to occur.

Competitive Inhibitor

Substance that binds to active site of enzyme.

Irreversible Inhibitor

Substance that permanently disables enzyme activity.

Non-competitive Inhibitor

Substance that binds to enzyme, not active site.

Negative Feedback Loop

Process where output inhibits its own production.

Glycolysis

First step in cellular respiration, breaking down glucose.

Polymers

Large molecules made of repeating monomer units.

Monomers

Small building blocks of polymers.

Nerve Gas

Irreversible inhibitor affecting nervous system enzymes.

Penicillin

Antibiotic that inhibits bacterial cell wall synthesis.

Energy Transfer

Process of converting energy from one form to another.

Photosynthesis

Process by which plants convert sunlight into energy.

Thermodynamic Efficiency

Measure of energy transfer efficiency in biological systems.

Glycolysis

Breakdown of glucose into pyruvate, producing ATP.

Fructose 1,6-bisphosphate

Intermediate formed from glucose in glycolysis.

Pyruvate

End product of glycolysis, transported to mitochondria.

Acetyl CoA

Product of pyruvate breakdown, enters citric acid cycle.

Citric Acid Cycle

Series of reactions producing energy carriers from Acetyl CoA.

NADH

Electron carrier produced in glycolysis and citric acid cycle.

FADH2

Electron carrier produced in citric acid cycle.

Oxaloacetate

Reactant in citric acid cycle, regenerated each cycle.

Electron Transport Chain

Final step of respiration, generates ATP using electrons.

ATP

Energy currency produced during glycolysis and citric acid cycle.

GTP

Energy molecule produced in citric acid cycle, similar to ATP.

Carbon Dioxide (CO2)

Waste product of pyruvate breakdown and citric acid cycle.

Cyanide

Inhibitor of complex IV in electron transport chain.

Alternative oxidase

Cyanide-resistant pathway in plants for electron transport.

NAD+

Oxidized form of NADH, accepts electrons during reactions.

CoA-SH

Coenzyme aiding in the conversion of pyruvate to Acetyl CoA.

Intermembrane space

Location where protons are pumped during electron transport.

Mitochondrial matrix

Site of pyruvate breakdown and citric acid cycle.

ATP Yield

Approximately 38 ATP produced from one glucose molecule.

Hydrogen ions (H+)

Protons involved in ATP synthesis during electron transport.

Glycolysis Products

2 ATP, 2 NADH, and 2 pyruvate produced in cytosol.

Oxidation

Loss of electrons, as seen in NAD+ to NADH.

Reduction

Gain of electrons, converting NAD+ to NADH.

Electron Transport Chain

Pumps H+ to create electrochemical gradient for ATP.

Alternative Oxidase

Bypasses Complex IV, accepts electrons without cyanide.

Symplocarpus foetidus

Plant that melts snow using alternative oxidase.

Reactive Oxygen Species (ROS)

Harmful byproducts reduced by alternative oxidase pathway.

Substrate-Level Phosphorylation

Direct ATP production in glycolysis and CAC.

Chemiosmotic Phosphorylation

ATP generation via electron transport chain process.

Glycolysis

Breaks down glucose to produce pyruvate and ATP.

Citric Acid Cycle (CAC)

Processes acetyl-CoA to generate ATP and NADH.

Fermentation

Converts pyruvate to lactate when oxygen is absent.

Lactate

Product of pyruvate reaction with NADH in muscles.

Photosynthesis Ingredients

Light, CO2, and water are essential for process.

Photosynthesis Goal

Produce glucose for cellular respiration, not O2.

Absorption Spectra

Plants absorb blue/red light, reflect green light.

Z Scheme

Describes light reactions' energy flow in photosynthesis.

NADPH

Produced in light reactions, used in Calvin Cycle.

ATP Synthase

Enzyme that synthesizes ATP from H+ flow.

Calvin Cycle

Uses ATP and NADPH to produce glucose.

Rubisco

Enzyme in Calvin Cycle affected by temperature.

Cold Temperature Effect

Slows Calvin Cycle due to enzyme affinity changes.

Excess ATP/NADPH

Result from light reactions outpacing Calvin Cycle.

Photosynthesis Model

Illustrates inputs/outputs of light reactions and Calvin Cycle.

Pyruvate Breakdown

Necessary for CAC, requires fats and proteins.

Dietary Variety Importance

Essential for cellular respiration beyond just glucose.