p.3
Metabolic Pathways: Catabolism and Anabolism
What is the role of an enzyme in a chemical reaction?
An enzyme speeds the reaction by reducing its activation energy (E A) without affecting the free-energy change (ΔG).
p.13
Anaerobic Cellular Respiration
What processes enable cells to produce ATP without oxygen?
Fermentation and anaerobic respiration.
p.14
Photosynthesis: Light Reactions and Calvin Cycle
How many chloroplasts does a typical mesophyll cell contain?
About 30 to 40 chloroplasts.
p.9
Oxidative Phosphorylation and Electron Transport Chain
What happens to electrons as they move down the electron transport chain?
They lose energy in several energy-releasing steps.
p.19
Photosynthesis: Light Reactions and Calvin Cycle
What happens to one molecule of G3P in the Calvin cycle?
It exits the cycle to be used by the plant cell.
p.16
Calvin Cycle and Pyruvate Oxidation
What are the other names for the Calvin cycle?
Dark reactions and light-independent reactions.
p.2
Metabolic Pathways: Catabolism and Anabolism
What does ΔG > 0 indicate?
An endergonic reaction where energy is required and the reaction is nonspontaneous.
p.11
Fermentation Processes
What is produced during lactic acid fermentation?
2 Lactate, with no release of CO2.
p.4
Energy and ATP in Living Systems
What types of work can ATP drive?
Mechanical work, chemical work, and transport work.
p.19
Photosynthesis: Light Reactions and Calvin Cycle
Which enzyme catalyzes the first step of the Calvin cycle?
RuBP carboxylase-oxygenase, commonly known as rubisco.
p.1
Metabolic Pathways: Catabolism and Anabolism
What do anabolic pathways do?
They consume energy to build complicated molecules from simpler ones.
p.11
Anaerobic Cellular Respiration
What is the role of sulfate-reducing bacteria in anaerobic respiration?
They have an electron transport chain but do not use oxygen as a final electron acceptor.
p.20
Alternative Carbon Fixation Mechanisms in Plants
What are the two distinct types of photosynthetic cells in C4 plants?
Bundle-sheath cells and mesophyll cells.
p.11
Fermentation Processes
What are the two main steps in alcohol fermentation?
1. 2 Pyruvate → 2 Acetaldehyde; 2. 2 Acetaldehyde → 2 Ethanol.
p.17
Photosynthesis: Light Reactions and Calvin Cycle
What is transferred to the primary electron acceptor in a photosystem?
An excited electron from the special pair of chlorophyll a molecules.
p.3
Metabolic Pathways: Catabolism and Anabolism
What is activation energy (E A)?
The energy necessary to break the bonds of the reactants in a chemical reaction.
p.1
Metabolic Pathways: Catabolism and Anabolism
What do catabolic pathways do?
They release energy by breaking down complex molecules into simpler compounds.
p.7
Citric Acid Cycle and Pyruvate Oxidation
What is produced during pyruvate oxidation?
CO2, NADH, and Acetyl CoA.
p.14
Photosynthesis: Light Reactions and Calvin Cycle
From where is the oxygen produced during photosynthesis derived?
From water (H2O), not from carbon dioxide (CO2).
p.1
Energy and ATP in Living Systems
What is the primary energy currency in living systems?
ATP (Adenosine Triphosphate).
p.14
Photosynthesis: Light Reactions and Calvin Cycle
What do photoautotrophs use to synthesize organic molecules?
Light energy, carbon dioxide, and usually water.
p.17
Photosynthesis: Light Reactions and Calvin Cycle
What happens when a photon strikes a pigment molecule in a light-harvesting complex?
The energy is passed from molecule to molecule until it reaches the reaction-center complex.
p.4
Energy and ATP in Living Systems
What is ATP's role in energy coupling?
ATP provides energy for various cellular processes by coupling exergonic and endergonic reactions.
p.5
Energy and ATP in Living Systems
What type of work does ATP provide energy for?
Chemical work, transport work, and mechanical work.
p.17
Photosynthesis: Light Reactions and Calvin Cycle
What is the first step of the light reactions?
The solar-powered transfer of an electron from the reaction-center chlorophyll a pair to the primary electron acceptor.
p.5
Aerobic Cellular Respiration
What is the overall reaction for cellular respiration?
The breakdown of glucose to produce energy.
p.6
Metabolic Pathways: Catabolism and Anabolism
What is substrate-level phosphorylation?
ATP synthesis occurs when an enzyme transfers a phosphate group from a substrate molecule to ADP.
p.8
Citric Acid Cycle and Pyruvate Oxidation
What is another name for the citric acid cycle?
The tricarboxylic acid cycle or the Krebs cycle.
p.5
Glycolysis and its Phases
What is glycolysis?
The first stage of cellular respiration where glucose is broken down.
p.9
Oxidative Phosphorylation and Electron Transport Chain
What drives the phosphorylation of ADP to form ATP during chemiosmosis?
The diffusion of H+ back into the matrix through ATP synthase.
p.18
Calvin Cycle and Pyruvate Oxidation
What type of process is the Calvin cycle?
Anabolic, building carbohydrates from smaller molecules and consuming energy.
p.13
Photosynthesis: Light Reactions and Calvin Cycle
What is the primary function of photosynthesis?
To convert light energy to the chemical energy of food.
p.6
Glycolysis and its Phases
What is the conversion of glucose during glycolysis?
1 glucose is converted to 2 pyruvate.
p.1
Aerobic Cellular Respiration
What are the two main types of cellular respiration?
Aerobic cellular respiration and anaerobic cellular respiration.
p.1
Anaerobic Cellular Respiration
What process occurs when oxygen is not available for energy production?
Anaerobic cellular respiration.
p.14
Photosynthesis: Light Reactions and Calvin Cycle
Where are chloroplasts mainly found in plants?
In the cells of the mesophyll.
p.20
Alternative Carbon Fixation Mechanisms in Plants
What do CAM plants do during the night?
Take up CO2 and incorporate it into organic acids.
p.2
Metabolic Pathways: Catabolism and Anabolism
What characterizes an exergonic reaction in terms of energy profile?
It releases energy and is spontaneous under standard conditions.
p.11
Fermentation Processes
What is the function of NADH in fermentation?
It transfers electrons to regenerate NAD+ from pyruvate or its derivatives.
p.15
Photosynthesis: Light Reactions and Calvin Cycle
What do the light reactions of photosynthesis convert?
Solar energy to chemical energy.
p.21
Photosynthesis: Light Reactions and Calvin Cycle
What is the primary function of photosynthesis?
To convert light energy to the chemical energy of food.
p.10
Anaerobic Cellular Respiration
What type of bacteria can perform anaerobic respiration using sulfate?
Sulfate reducing bacteria.
p.11
Fermentation Processes
What is fermentation?
A way of harvesting chemical energy without using oxygen or an electron transport chain.
p.5
Aerobic Cellular Respiration
What are the three main stages of aerobic cellular respiration?
Glycolysis, pyruvate oxidation and the citric acid cycle, oxidative phosphorylation.
p.20
Alternative Carbon Fixation Mechanisms in Plants
What is the mode of carbon fixation used by CAM plants called?
Crassulacean acid metabolism (CAM).
p.3
Energy and ATP in Living Systems
What are the three main types of work that ATP is involved in?
Chemical work, transport work, and mechanical work.
p.13
Fermentation Processes
What is the final electron acceptor in fermentation?
An organic molecule (e.g., acetaldehyde in alcohol fermentation, pyruvate in lactic acid fermentation).
p.3
Energy and ATP in Living Systems
What are the components of ATP (adenosine triphosphate)?
Sugar ribose, nitrogenous base adenine, and a chain of three phosphate groups.
p.9
Oxidative Phosphorylation and Electron Transport Chain
What is the final electron acceptor in the electron transport chain?
Oxygen (O2), which is reduced to water (H2O).
p.3
Energy and ATP in Living Systems
What happens during the hydrolysis of ATP?
ATP is converted into ADP (adenosine diphosphate) and inorganic phosphate (Pi), releasing energy.
p.13
Metabolic Pathways: Catabolism and Anabolism
Can carbohydrates, fats, and proteins be used as fuel for cellular respiration?
Yes, they can all be used as fuel.
p.19
Photosynthesis: Light Reactions and Calvin Cycle
What is the final product of the Calvin cycle?
G3P (glyceraldehyde-3-phosphate).
p.4
Metabolic Pathways: Catabolism and Anabolism
What does ΔG < 0 indicate?
An exergonic reaction where energy is released and the reaction is spontaneous.
p.7
Aerobic Cellular Respiration
What happens to pyruvate in eukaryotic cells when O2 is present?
It enters a mitochondrion where the oxidation of glucose is completed.
p.14
Photosynthesis: Light Reactions and Calvin Cycle
What is the function of veins in plants related to photosynthesis?
Deliver water from roots to leaves and export sugar from leaves to roots and other non-photosynthetic parts.
p.7
Citric Acid Cycle and Pyruvate Oxidation
What does the citric acid cycle complete?
The energy-yielding oxidation of organic molecules.
p.1
Metabolic Pathways: Catabolism and Anabolism
What type of work is involved in catabolism?
Chemical work, transport work, and mechanical work.
p.4
Energy and ATP in Living Systems
What are examples of mechanical work driven by ATP?
Beating of cilia, contraction of muscle cells, and movement of chromosomes during cellular reproduction.
p.5
Oxidative Phosphorylation and Electron Transport Chain
What occurs during oxidative phosphorylation?
Electron transport and chemiosmosis.
p.6
Glycolysis and its Phases
Is carbon released as CO2 during glycolysis?
No, no carbon is released as CO2 during glycolysis.
p.2
Metabolic Pathways: Catabolism and Anabolism
What does ΔG < 0 indicate?
An exergonic reaction where energy is released and the reaction is spontaneous.
p.17
Photosynthesis: Light Reactions and Calvin Cycle
What is a photosystem composed of?
A reaction-center complex surrounded by several light-harvesting complexes.
p.4
Metabolic Pathways: Catabolism and Anabolism
What does ΔG > 0 indicate?
An endergonic reaction where energy is required and the reaction is nonspontaneous.
p.1
Fermentation Processes
What is fermentation?
A metabolic process that converts sugar to acids, gases, or alcohol in the absence of oxygen.
p.2
Metabolic Pathways: Catabolism and Anabolism
What are the standard conditions for measuring free-energy change?
1 M of each reactant and product, 25 °C, pH 7.
p.1
Aerobic Cellular Respiration
What are the three main stages of aerobic respiration?
Glycolysis, pyruvate oxidation and the citric acid cycle, and oxidative phosphorylation.
p.2
Metabolic Pathways: Catabolism and Anabolism
What is the role of enzymes in reactions?
Enzymes speed up reactions by lowering the activation energy.
p.19
Photosynthesis: Light Reactions and Calvin Cycle
What is the first step of the Calvin cycle?
Carbon fixation, where CO2 is attached to ribulose bisphosphate (RuBP).
p.4
Energy and ATP in Living Systems
How does ATP facilitate transport work?
By pumping substances across membranes against the direction of spontaneous movement.
p.2
Metabolic Pathways: Catabolism and Anabolism
What is the significance of activation energy in reactions?
It is the energy required to initiate a reaction, influencing the rate of the reaction.
p.16
Calvin Cycle and Pyruvate Oxidation
What is the initial step of the Calvin cycle?
Incorporating CO2 from the air into organic molecules in the chloroplast.
p.12
Fermentation Processes
What is the final electron acceptor in fermentation?
An organic molecule (e.g., acetaldehyde in alcohol fermentation, pyruvate in lactic acid fermentation).
p.6
Glycolysis and its Phases
What does glycolysis do?
Glycolysis harvests chemical energy by oxidizing glucose to pyruvate.
p.9
Aerobic Cellular Respiration
What is the total ATP yield from glycolysis and the citric acid cycle combined?
38 ATP per molecule of glucose.
p.16
Photosynthesis: Light Reactions and Calvin Cycle
Where do the light reactions occur?
In the thylakoids of the chloroplast.
p.21
Photosynthesis: Light Reactions and Calvin Cycle
What are photosystems composed of?
A reaction-center complex surrounded by light-harvesting complexes.
p.12
Metabolic Pathways: Catabolism and Anabolism
What does a negative ΔG indicate about a reaction?
The reaction is exergonic, meaning it releases energy and occurs spontaneously.
p.17
Photosynthesis: Light Reactions and Calvin Cycle
What is the role of the special pair of chlorophyll a molecules?
They can use energy from light to boost one of their electrons to a higher energy level and transfer it to the primary electron acceptor.
p.7
Citric Acid Cycle and Pyruvate Oxidation
What is the role of Acetyl CoA in the citric acid cycle?
It combines with oxaloacetate to form citrate.
p.14
Photosynthesis: Light Reactions and Calvin Cycle
What are the two stages of photosynthesis?
The light reactions and the Calvin cycle.
p.5
Citric Acid Cycle and Pyruvate Oxidation
What is the role of pyruvate oxidation in cellular respiration?
It converts pyruvate into acetyl-CoA for the citric acid cycle.
p.19
Photosynthesis: Light Reactions and Calvin Cycle
What is the role of light reactions in relation to the Calvin cycle?
Light reactions regenerate ATP and NADPH needed for the Calvin cycle.
p.9
Oxidative Phosphorylation and Electron Transport Chain
What is the role of the proton motive force in ATP synthesis?
It drives the phosphorylation of ADP to form ATP.
p.10
Anaerobic Cellular Respiration
What allows cells to produce ATP without oxygen?
Anaerobic respiration and fermentation.
p.6
Glycolysis and its Phases
What is the energy investment phase in glycolysis?
It involves the use of 2 ATP to initiate the process.
p.15
Photosynthesis: Light Reactions and Calvin Cycle
What does CAM stand for in the context of photosynthesis?
Crassulacean Acid Metabolism.
p.16
Photosynthesis: Light Reactions and Calvin Cycle
What is the wavelength range of visible light important for photosynthesis?
From about 380 nm to 750 nm.
p.12
Glycolysis and its Phases
What does glycolysis accomplish?
It harvests chemical energy by oxidizing glucose to pyruvate.
p.4
Energy and ATP in Living Systems
What is the significance of the hydrolysis of ATP?
It releases energy that can be used for cellular work.
p.13
Metabolic Pathways: Catabolism and Anabolism
Where do monomers of carbohydrates, fats, and proteins enter cellular respiration?
At various points in glycolysis or the citric acid cycle.
p.21
Photosynthesis: Light Reactions and Calvin Cycle
What occurs during the light reactions in the thylakoid membranes?
Water is split, releasing O2, producing ATP, and forming NADPH.
p.13
Energy and ATP in Living Systems
How does energy flow in an ecosystem?
Energy flows in as sunlight and leaves as heat, while essential chemical elements are recycled.
p.15
Photosynthesis: Light Reactions and Calvin Cycle
What is the first product of the Calvin Cycle in C-3 plants?
3-phosphoglyceric acid (3-PGA).
p.15
Photosynthesis: Light Reactions and Calvin Cycle
Which plants are examples of C-3 plants?
Rice, wheat, and soybean.
p.16
Photosynthesis: Light Reactions and Calvin Cycle
What are pigments?
Substances that absorb visible light.
p.21
Alternative Carbon Fixation Mechanisms in Plants
How do C4 plants fix carbon?
They incorporate CO2 into four-carbon compounds in mesophyll cells, which are then exported to bundle-sheath cells.
p.6
Oxidative Phosphorylation and Electron Transport Chain
What is oxidative phosphorylation?
ATP synthesis occurs by the use of energy released by the electron transport chain.
p.3
Aerobic Cellular Respiration
What are the main stages of aerobic cellular respiration?
Glycolysis, pyruvate oxidation and the citric acid cycle, and oxidative phosphorylation.
p.19
Photosynthesis: Light Reactions and Calvin Cycle
What are the energy requirements for the Calvin cycle to synthesize one G3P molecule?
The cycle consumes 9 ATP and 6 NADPH.
p.7
Citric Acid Cycle and Pyruvate Oxidation
What is substrate-level phosphorylation?
A process that generates ATP directly in the citric acid cycle.
p.8
Citric Acid Cycle and Pyruvate Oxidation
What are the total ATP and NADH produced in the citric acid cycle from one glucose molecule?
2 ATP, 6 NADH, and 2 FADH2.
p.21
Photosynthesis: Light Reactions and Calvin Cycle
What does the Calvin cycle produce from CO2?
Sugar, using ATP for energy and NADPH for reducing power.
p.8
Oxidative Phosphorylation and Electron Transport Chain
What is the role of NADH in oxidative phosphorylation?
It transfers electrons to the electron transport chain, creating a proton motive force to produce ATP.
p.6
Glycolysis and its Phases
Does glycolysis require oxygen?
Glycolysis occurs whether or not O2 is present.
p.12
Citric Acid Cycle and Pyruvate Oxidation
How do fatty acids enter the citric acid cycle?
They undergo beta oxidation to form two-carbon fragments, which enter as acetyl CoA.
p.18
Calvin Cycle and Pyruvate Oxidation
What is the third phase of the Calvin cycle?
Regeneration of the CO2 acceptor (RuBP).
p.6
Aerobic Cellular Respiration
What are the three metabolic stages of cellular respiration?
(1) Glycolysis, (2) Pyruvate oxidation & the citric acid cycle, (3) Oxidative phosphorylation (electron transport and chemiosmosis).
p.16
Calvin Cycle and Pyruvate Oxidation
What is carbon fixation?
The initial incorporation of carbon into organic compounds.
p.16
Photosynthesis: Light Reactions and Calvin Cycle
What do the light reactions convert solar energy into?
Chemical energy in the form of ATP and NADPH.
p.21
Photosynthesis: Light Reactions and Calvin Cycle
What distinguishes Photosystem II?
It contains P680 chlorophyll a molecules in the reaction-center complex.
p.21
Alternative Carbon Fixation Mechanisms in Plants
How do CAM plants adapt to arid climates?
They open their stomata at night to incorporate CO2 into organic acids, which are stored and used during the day.
p.15
Photosynthesis: Light Reactions and Calvin Cycle
What process powers the addition of a phosphate group to ADP in the light reactions?
Chemiosmosis, through photophosphorylation.
p.10
Metabolic Pathways: Catabolism and Anabolism
What are the three main stages of aerobic cellular respiration?
1. Glycolysis, 2. Pyruvate oxidation and the citric acid cycle, 3. Oxidative phosphorylation.
p.19
Photosynthesis: Light Reactions and Calvin Cycle
What is required for the Calvin cycle to continue after regeneration of RuBP?
CO2 must be received again.
p.16
Photosynthesis: Light Reactions and Calvin Cycle
Where does the Calvin cycle take place?
In the stroma of the chloroplast.
p.10
Anaerobic Cellular Respiration
Do sulfate reducing bacteria use oxygen as a final electron acceptor?
No, they do not use oxygen as a final electron acceptor.
p.16
Photosynthesis: Light Reactions and Calvin Cycle
Why are leaves green?
Because chlorophyll absorbs most wavelengths except green.
p.21
Photosynthesis: Light Reactions and Calvin Cycle
What happens when chlorophyll a absorbs energy?
An electron is boosted to a higher energy level and transferred to the primary electron acceptor.
p.15
Photosynthesis: Light Reactions and Calvin Cycle
When does the Calvin Cycle occur in CAM plants?
At night when the stomata are open.
p.21
Photosynthesis: Light Reactions and Calvin Cycle
What distinguishes Photosystem I?
It contains P700 chlorophyll a molecules.
p.12
Aerobic Cellular Respiration
What are the three stages of aerobic respiration?
1) Glycolysis, 2) Pyruvate oxidation and the citric acid cycle, 3) Oxidative phosphorylation.
p.12
Metabolic Pathways: Catabolism and Anabolism
What is the role of enzymes in metabolic reactions?
Enzymes speed up reactions by lowering energy barriers without affecting the free-energy change (ΔG).
