Aerobic Cellular Respiration Quiz

Overview of Cellular Respiration

• Cellular respiration is a set of metabolic reactions and processes that take place within organisms to convert the chemical energy from nutrients into ATP (adenosine triphosphate), and then release waste products.
• The process involves a series of redox reactions to produce ATP.
• The first step of cellular respiration is glycolysis.
• The second step is pyruvate oxidation.
• The third step is the Krebs cycle.
• The fourth step is oxidative phosphorylation.
• The process occurs in the presence of oxygen (aerobic) or absence of oxygen (anaerobic).

Overview of Metabolic Processes

• The lesson list details the various lesson topics within Unit 2, Metabolic Processes.
• The topics covered include: an overview of cellular respiration, glycolysis & pyruvate oxidation, the Krebs cycle, oxidative phosphorylation and electron transport chain, anaerobic cellular respiration and fermentation, cellular respiration summary, photosynthesis introduction and light-dependent reactions, Calvin Cycle and alternative mechanisms of carbon fixation, as well as comparing photosynthesis and cellular respiration.
• The lesson list also includes assigned homework problems for textbook material and worksheets.
• There are also assessment details including Tylenol case study and exercise lab work.

First Law of Thermodynamics

• The total energy of a closed system remains constant; energy cannot be created or destroyed but can be transferred or transformed.
• Sunlight is a form of energy that can be converted into chemical energy by plants.
• When bonds between reactant molecules break down, energy is absorbed.
• The formation of bonds between product molecules releases energy.

Second Law of Thermodynamics

• In energy transfer or conversion, some energy becomes unusable and increases the entropy (disorder) of the universe.
• Disorder increases when a system transitions from a more ordered to a more random state.
• The overall energy change in any process or reaction is accompanied by changes in entropy.

Gibbs Free Energy

• The energy available to do useful work in a chemical or physical system.

• The change in free energy determines whether a reaction is spontaneous or not.

• Exergonic reactions release free energy (ΔG<0); these reactions are spontaneous.

• Endergonic reactions absorb free energy (ΔG>0); these reactions are not spontaneous, requiring energy input to occur.

• Energy coupling links exergonic reactions to provide the energy needed for endergonic reactions.

• Catabolic pathways break down complex molecules into simpler compounds and release energy. These are exergonic.

• Anabolic pathways build simpler molecules into complex compounds and require energy. These are endergonic.

Enzymes and Activation Energy

• Enzymes speed up reactions by lowering the activation energy needed for the reaction to proceed.

• The active site of an enzyme is shaped to facilitate the interaction between reactant molecules (substrates) that bind and undergo reactions.

• Three mechanisms by which enzymes reduce activation energy are bringing molecules together, altering charged environments of the reactants and changing the shape of a substrate.

Aerobic Cellular Respiration

• This process occurs with oxygen; it breaks down glucose and releases energy for the organism in the form of ATP.
• It involves the following steps: glycolysis, pyruvate oxidation, Krebs' cycle and oxidative phosphorylation, and the release of 36 ATPs from each glucose molecule.
• Three overall goals of cellular respiration are to break down bonds in glucose to produce carbon dioxide, move hydrogen electrons from glucose to oxygen to produce water molecules, and trap as much free energy as possible in the form of ATP.

Substrate-Level Phosphorylation

• Enzymes directly transfer a phosphate group from an intermediary phosphorylated compound such as phosphoenolpyruvate to ADP to form ATP.

Oxidative Phosphorylation

• Energy transferred from electrons in reactions indirectly forms ATP from ADP.
• Redox reactions occur in the mitochondria and electrons are passed along an electron transport chain until they reach oxygen which is the final electron acceptor.
• Two important coenzymes in electron transfer are NAD+ and FAD.
• NAD+ is reduced to NADH+H+ , and FAD is reduced to FADH2.

Mitochondrion

• The mitochondrion is the site of oxidative phosphorylation in eukaryotes.
• Mitochondria are composed of an outer and inner membrane, an intermembrane space and a matrix.
• Aerobic phases such as pyruvate oxidation, Krebs cycle and oxidative Phosphorylation occur within the mitochondria.

Anaerobic Respiration

• Respiration that occurs in the absence of oxygen and a different final inorganic electron acceptor.

Fermentation

• Occurs in the absence of oxygen (anaerobic) and requires a different final inorganic oxidizing agent to proceed.
• Two types: lactic acid fermentation and alcohol fermentation.

The Glycolysis Process

• Step-by-step process starting with glucose, and describing the products, location and energy type.
• Specific enzymes are identified.

Krebs Cycle

• This is a cyclical process that occurs in the mitochondria.
• Two carbons produced from acetyl-CoA enter the Krebs Cycle where the carbons exit as waste (CO2).
• The process generates high energy molecules including (NADH, and FADH2).
• In each turn of the cycle, one ATP is made via substrate-level phosphorylation.

Comparing Cellular Respiration and Photosynthesis

• Cellular respiration and photosynthesis are complementary processes
• Basic information of cellular respiration (inputs/outputs)

Light-Dependent Reactions

• It is the first stage of photosynthesis.
• Involves capturing light energy to produce ATP and NADPH using water as an electron donor.

Photosystems

• PSII and PSI contain chlorophyll a and accessory pigments are embedded in the membrane.

Photosynthesis Summary

• Two main stages (light-dependent and Calvin cycle) with multiple specific steps

Alternative Mechanisms

• Plants often use adaptations such as C4 and CAM mechanisms.
• C4 plants spatially separate light reaction from dark reactions; CAM plants temporally separate light and dark reactions.

Test your knowledge on the four main stages of aerobic cellular respiration and the biochemical processes involved. This quiz covers glycolysis, the Krebs cycle, and oxidative phosphorylation, including key concepts like substrate-level phosphorylation and energy production. Perfect for understanding the intricacies of cellular respiration.