Bio Lect 5 Flashcards
1
Q
What is the first law of thermodynamics?
A
No energy can be lost within the Universe. Energy can be converted from one form into another.
The first law is also known as the law of energy conservation.
2
Q
What does the second law of thermodynamics state?
A
Every energy transfer increases the entropy (chaos) of the Universe.
This law takes the environment into account.
3
Q
Fill in the blank: The first law of thermodynamics applies to a _______.
A
[closed system]
4
Q
True or False: The first law of thermodynamics states that energy can be lost in the Universe.
A
False
5
Q
What happens to some energy during each energy transfer according to the second law of thermodynamics?
A
Some energy is lost to the environment as heat and sound.
6
Q
What is entropy in the context of the second law of thermodynamics?
A
Entropy refers to chaos or disorder in the Universe.
7
Q
Fill in the blank: In energy transformations, each time energy is transformed, there will be an increase in _______.
A
[entropy]
8
Q
What is the primary reason organisms require constant energy input?
A
Organisms lose some of their energy to the environment, typically as heat.
This energy loss necessitates a continuous input of energy for survival.
9
Q
What happens to energy during conversion in living organisms?
A
Not all forms of energy can be converted into biologically relevant work, and some energy is lost as heat.
This aligns with the second law of thermodynamics.
10
Q
What is an example of irreversible energy fixing in organisms?
A
Secondary metabolites in plants.
These include substances produced for taste or odor that cannot be broken down for energy later.
11
Q
What is the relationship between energy transformation and entropy according to the second law of thermodynamics?
A
Every energy transfer increases the entropy of the Universe.
Giving off heat is one way of increasing entropy.
12
Q
What type of energy do living organisms primarily obtain from food?
A
Chemical energy.
This chemical energy is then converted into work or stored as fat.
13
Q
Fill in the blank: An organism fixes some of its energy __________ in certain chemicals that cannot be broken down later.
A
irreversibly.
These chemicals are often end products of one-way metabolic pathways.
14
Q
How do active individuals utilize the energy from food?
A
They convert most of the energy contained in food into work.
Some of the energy is stored as fat, while a significant amount is lost as heat.
15
Q
True or False: Living organisms can switch their energy consumption on and off like a car engine.
A
False.
Living organisms continuously convert energy forms to stay alive.
16
Q
What is the main waste product of energy transformation in living organisms?
A
Heat.
This heat represents energy lost to the environment.
17
Q
What role do secondary metabolites play in plants?
A
They produce substances for taste and odor, which are examples of irreversible energy fixing.
These metabolites cannot be used again for energy harvesting.
18
Q
What is energy balance in the context of ecosystems and individuals?
A
Energy balance refers to the relationship between energy conversion and energy loss in ecosystems and individual organisms.
It involves understanding how energy is harnessed and utilized within biological systems.
19
Q
What is the primary process by which plants convert light energy?
A
Photosynthesis occurs in chloroplasts, where plants convert light energy into organic molecules.
This process uses carbon dioxide and water to produce glucose and oxygen.
20
Q
Where does cellular respiration occur?
A
Cellular respiration occurs in mitochondria, which are present in both plants and animals.
This process involves oxidizing nutrients to obtain energy.
21
Q
What is the role of ATP in cellular processes?
A
ATP serves as the cell’s energy currency, powering most cellular work.
ATP is produced during cellular respiration.
22
Q
What are the waste products of cellular respiration?
A
The waste products of cellular respiration are carbon dioxide and water.
These are released after the conversion of sugar and oxygen.
23
Q
What is the relationship between photosynthesis and cellular respiration?
A
Photosynthesis and cellular respiration are linked processes that recycle energy and matter in ecosystems.
Photosynthesis produces organic molecules used in cellular respiration.
24
Q
Fill in the blank: The process by which an organism obtains energy by oxidizing nutrients is called _______.
A
cellular respiration
25
What type of energy loss typically occurs during energy conversion processes?
Energy is typically lost in the form of heat.
## Footnote
This loss occurs during both photosynthesis and cellular respiration.
26
What is the primary function of chloroplasts in plants?
Chloroplasts capture light energy and convert it into chemical energy through photosynthesis.
## Footnote
This includes the transformation of carbon dioxide and water into glucose.
27
True or False: All food is ultimately based on organic molecules produced by animals.
False
## Footnote
All food is ultimately based on plants that contain chloroplasts.
28
What do organic molecules provide for animals?
Organic molecules provide energy for animals, which they obtain from food.
## Footnote
This energy is harvested from the chemical bonds within organic molecules, such as glucose.
29
What does ATP act as within the cell?
Energy reservoir
## Footnote
ATP is crucial for providing energy for various cellular activities.
30
What is metabolism?
Totality of organism's chemical reactions
## Footnote
It encompasses all biochemical processes occurring within an organism.
31
Define anabolism.
Use energy to build complex molecules
## Footnote
Example: protein synthesis from amino acids.
32
Give an example of catabolism.
Breakdown of glucose in glycolysis
## Footnote
Catabolism involves releasing energy through the breakdown of molecules.
33
What is the role of ATP in cellular work?
Provides energy for chemical, transport, and movement work
## Footnote
ATP is essential for various cellular processes, including maintaining concentration gradients.
34
What occurs during the anabolic pathway?
Energy is needed to build complex molecules
## Footnote
This process is essential for growth and repair within cells.
35
What does catabolism do?
Releases energy through molecule breakdown
## Footnote
This process allows organisms to harvest energy stored in food.
36
Fill in the blank: Anabolism uses energy while _______ releases energy.
Catabolism
## Footnote
These processes are complementary in metabolism.
37
What is the significance of the net energy in metabolic pathways?
It reflects the overall effect from substrate to product
## Footnote
Not every step in the pathway generates or uses energy.
38
True or False: All steps in a metabolic pathway generate energy.
False
## Footnote
Some steps may require energy input, while others release energy.
39
What is a good analogy for catabolism?
A ball rolling down a mountain
## Footnote
This analogy illustrates how energy is released in a stepwise manner.
40
What is Gibbs free energy?
The portion of the system's energy that can perform work
## Footnote
Introduced by J. W. Gibbs in 1878.
41
What is the equation for the change in Gibbs free energy?
ΔG = ΔH - TΔS
## Footnote
Where ΔG is the change in free energy, ΔH is the change in enthalpy, T is the temperature, and ΔS is the change in entropy.
42
What does ΔG represent in a reaction or transport process?
The change in Gibbs free energy of the system
## Footnote
A negative ΔG indicates a spontaneous process.
43
What must happen for a reaction or transport process to occur spontaneously?
Gibbs free energy must decrease (ΔG is negative)
## Footnote
This is a fundamental principle in thermodynamics.
44
What components make up the universe in thermodynamics?
System + surroundings
## Footnote
This concept helps in understanding energy exchanges.
45
What does the term 'enthalpy' refer to?
The total energy change of the system
## Footnote
Enthalpy is a measure of total heat content.
46
What does the term 'entropy' refer to?
The change in disorder of the system
## Footnote
Entropy is a measure of randomness or disorder.
47
Fill in the blank: A process can only occur spontaneously if it decreases _______.
Gibbs free energy
48
True or False: Heat is often associated with energy lost to the environment.
True
## Footnote
This is relevant in the context of energy transformations.
49
What is the significance of the temperature in the Gibbs free energy equation?
It multiplies the change in entropy
## Footnote
Temperature affects how much energy is available to do work.
50
What is an example of a process that can change Gibbs free energy?
Metabolic reaction, membrane transport, or muscle fibre movement
## Footnote
These processes involve energy transformations in biological systems.
51
What is Gibbs free energy?
A thermodynamic potential that measures the maximum reversible work obtainable from a thermodynamic system at constant temperature and pressure.
## Footnote
It is commonly denoted as G.
52
What is an exergonic reaction?
A chemical reaction that releases energy, characterized by a negative change in Gibbs free energy (ΔG < 0).
## Footnote
This means the products have less free energy than the reactants.
53
What is an endergonic reaction?
A chemical reaction that requires energy input, characterized by a positive change in Gibbs free energy (ΔG > 0).
## Footnote
This means the products have more free energy than the reactants.
54
What does ΔG represent?
The change in free energy, calculated as the free energy of products minus the free energy of reactants.
## Footnote
A negative ΔG indicates an exergonic reaction, while a positive ΔG indicates an endergonic reaction.
55
How do exergonic reactions relate to spontaneity?
Exergonic reactions can occur spontaneously and release energy.
## Footnote
They are comparable to a ball rolling downhill, which does not require additional energy input.
56
How do endergonic reactions relate to energy input?
Endergonic reactions require the input of energy to occur.
## Footnote
They are comparable to a ball needing energy to roll uphill.
57
What is the relationship between exergonic and endergonic reactions in metabolic pathways?
Exergonic reactions can provide the energy required to drive endergonic reactions.
## Footnote
This linking conserves energy and minimizes waste.
58
What does metabolism do in terms of energy efficiency?
Metabolism minimizes the amount of energy wasted as heat.
## Footnote
It links reactions to utilize energy released from exergonic reactions to power endergonic reactions.
59
Fill in the blank: In an exergonic reaction, the products have _____ free energy than the starting molecules.
less
60
Fill in the blank: In an endergonic reaction, the products have _____ free energy than the reactants.
more
61
What do enzymes regulate?
Metabolism
## Footnote
Enzymes play a crucial role in controlling metabolic processes.
62
What are metabolic pathways composed of?
A group of enzyme-catalysed reactions
## Footnote
These pathways facilitate the conversion of reactants to products.
63
How do enzymes affect activation energy?
They lower the activation energy required to kick-start a reaction
## Footnote
This makes it easier for reactions to occur.
64
What factors can affect enzyme function?
pH levels
## Footnote
Enzymes are often pH-dependent, meaning their activity can be influenced by the acidity or alkalinity of their environment.
65
What are two ways enzymes are regulated?
Gene expression and protein modification
## Footnote
Protein modification can include processes like phosphorylation.
66
What is negative feedback in the context of enzymes?
Enzymes are often inhibited by the end product in a pathway
## Footnote
This regulation helps maintain homeostasis within metabolic pathways.
67
What is the role of the transition state in enzyme-catalysed reactions?
It is the unstable state formed during the conversion of reactants to products
## Footnote
Enzymes help stabilize this state to lower activation energy.
68
Do enzymes change the Gibbs free energy of a reaction?
No
## Footnote
Enzymes do not alter the overall energy change of a reaction but facilitate the process.
69
Fill in the blank: Enzymes interact with their substrates to destabilize their chemical bonds to form a _______.
Transition state
## Footnote
This process is essential for lowering activation energy.
70
What happens to enzymes in response to environmental pH changes?
Their structure and function can be affected
## Footnote
This is a key regulatory mechanism for enzyme activity.
71
What is one example of protein modification that regulates enzyme function?
Phosphorylation
## Footnote
This process can activate or deactivate enzymes.
72
What is ATP used for in biological systems?
ATP is used as an energy currency
## Footnote
ATP provides energy for various cellular processes.
73
What happens to ATP when the outermost inorganic phosphate (Pi) is cleaved off?
It releases energy and yields adenosine-diphosphate (ADP)
## Footnote
This reaction is exergonic, releasing a significant amount of energy.
74
Why is the outermost phosphate group in ATP considered to have high potential chemical energy?
Because the negative charges repel each other
## Footnote
The repulsion between negatively charged phosphate groups contributes to the energy storage.
75
What is the ΔG value associated with the cleavage of the outermost phosphate group from ATP?
-7.3 kcal/mol (-30.5 kJ/mol)
## Footnote
This indicates the amount of energy released during the reaction.
76
What are the components of ATP?
Adenine, ribose, and three phosphate groups
## Footnote
These components make ATP a nucleotide that also serves as a substrate for RNA synthesis.
77
What is the molecule that remains after the cleavage of the outermost phosphate group from ATP?
Adenosine-diphosphate (ADP)
## Footnote
ADP can be converted back to ATP through cellular respiration.
78
True or False: ATP can be directly coupled to all cellular work.
False
## Footnote
Not all reactions can be fueled directly by ATP; sometimes energy must be stored temporarily.
79
Fill in the blank: ATP is composed of the nitrogenous base ______, the sugar ribose, and three phosphate groups.
adenine
## Footnote
Adenine is one of the four nucleobases in the nucleic acid of DNA and RNA.
80
Why do we not constantly need to eat to have energy to move around?
Because we need means to transiently store the energy released by exergonic reactions
## Footnote
ATP serves as this temporary energy storage mechanism.
81
What role does ATP play in metabolic pathways?
ATP is either consumed or released
## Footnote
It acts as a key player in energy transfer during metabolic reactions.
82
What is ATP used for in biological systems?
ATP is used as an energy currency
## Footnote
ATP releases energy when phosphate groups are cleaved off
83
What happens when the outermost inorganic phosphate (Pi) is cleaved off ATP?
It releases energy and yields adenosine-diphosphate (ADP)
## Footnote
This reaction is exergonic, releasing -7.3 kcal/mol (-30.5 kJ/mol)
84
Why does the outermost phosphate group of ATP have high potential chemical energy?
Because the negative charges repel each other
## Footnote
This repulsion requires energy to attach the phosphate group to ATP
85
What are the components of ATP?
Adenine, ribose, and three phosphate groups
## Footnote
ATP stands for adenosine-triphosphate
86
What molecule remains after the cleavage of the outermost phosphate from ATP?
Adenosine-diphosphate (ADP)
## Footnote
ADP is formed when ATP loses one phosphate group
87
True or False: ATP can only be used directly for cellular work.
False
## Footnote
ATP cannot always fuel reactions directly due to spatial and temporal limitations
88
Fill in the blank: The negative charges of the phosphates in ATP ______ each other.
repel
## Footnote
This repulsion contributes to the high energy potential of ATP
89
What does a negative delta G value indicate about the reaction involving ATP?
It indicates that the reaction is exergonic
## Footnote
A negative delta G signifies that energy is released
90
What role does ATP play in metabolic pathways?
ATP is either consumed or released
## Footnote
ATP is a central molecule in energy transfer during metabolism
91
In addition to energy storage, what other function does ATP serve?
It provides one of the nucleotides for RNA synthesis
## Footnote
ATP is also involved in genetic processes
92
What is the primary function of ATP in cellular processes?
ATP is used as an energy currency
## Footnote
ATP (adenosine triphosphate) is crucial for storing and transferring energy in cells.
93
What is the Gibbs free energy?
A thermodynamic potential that measures the maximum reversible work
## Footnote
It is used to predict the direction of chemical reactions.
94
What are the two basic mechanisms for ATP formation?
* Substrate-level phosphorylation
* Oxidative phosphorylation
## Footnote
These mechanisms describe how ATP is generated during cellular respiration.
95
Define substrate-level phosphorylation.
Transfer of a phosphate group directly from a substrate molecule onto ADP
## Footnote
It occurs in pathways like glycolysis.
96
What is an example of substrate-level phosphorylation?
Glycolysis: phosphoglycerokinase
## Footnote
This enzyme transfers a phosphate group to ADP to form ATP.
97
What is oxidative phosphorylation?
A process where ATP is formed using a proton gradient across a membrane
## Footnote
It is often associated with chemiosmosis.
98
What is chemiosmosis?
Movement of ions down their electrochemical gradient across a semipermeable membrane
## Footnote
Essential for ATP synthesis in mitochondria.
99
What role does ATP synthase play in ATP production?
It synthesizes ATP by utilizing the energy from protons moving down their gradient
## Footnote
ATP synthase is located in the inner mitochondrial membrane.
100
How does the movement of protons generate ATP?
Protons move down their concentration gradient, driving the rotation of ATP synthase
## Footnote
This motion facilitates the binding of ADP and inorganic phosphate to form ATP.
101
What is the analogy used to describe ATP synthesis?
Comparable to a hydraulic power station, where a waterfall drives a turbine
## Footnote
This analogy illustrates how proton flow generates energy for ATP synthesis.
102
Where is ATP synthase located?
* Inner mitochondrial membrane
* Chloroplasts
* Plasma membrane of prokaryotes
## Footnote
ATP synthase is essential for ATP production in various organisms.
103
What happens to the substrate during substrate-level phosphorylation?
It loses its energy-rich phosphate group and is de-phosphorylated
## Footnote
This allows ADP to be phosphorylated to form ATP.
104
True or False: Membrane pumps consume ATP to create a proton gradient.
True
## Footnote
These pumps are known as ATPases.
105
What is the role of the rotor in ATP synthase?
It spins to translate the energy of proton movement into conformational changes
## Footnote
These changes facilitate the formation of ATP from ADP and inorganic phosphate.
106
Fill in the blank: The process of creating a proton gradient across a membrane is called _______.
[Chemiosmosis]
## Footnote
This process is crucial for ATP production in cellular respiration.
107
What structural feature of ATP synthase was solved by crystallization?
Its three-dimensional structure
## Footnote
This discovery is significant in understanding how ATP is synthesized.
108
What reflects the different affinity of atoms to incorporate or release electrons?
Redox potential
## Footnote
Redox potential is related to electronegativity.
109
What is the relationship between sugars and their electronegativity?
Sugars are weakly electronegative
## Footnote
This means it requires little effort to snatch up electrons from their atoms.
110
What happens when electrons are relocated from sugars to oxygen?
Energy is released
## Footnote
This process decreases the free energy (delta G is negative).
111
What is the role of the electron transport chain?
It involves several membrane-bound protein complexes that facilitate electron transfer
## Footnote
This process is crucial for energy release from food molecules.
112
What remains after an electron is taken from a hydrogen atom?
A proton
## Footnote
The proton can contribute to the electrochemical gradient used in chemiosmosis.
113
Fill in the blank: Another energy source comes from electrons that can be released from molecules in our food, such as _______.
sugars
114
What is the significance of free energy, G, in the context of electron movement from sugars to oxygen?
It becomes negative
## Footnote
This indicates that the process releases energy.
115
True or False: Electrons are directly passed from sugars to oxygen.
False
## Footnote
Electrons move through the electron transport chain, not directly.
116
What do we need to transiently store energy from electrons of sugars?
A currency
## Footnote
This currency allows the energy to be fed into the electron transport chain.
117
What is NADH used for?
As an electron currency
## Footnote
NADH plays a crucial role in cellular respiration and energy production.
118
What does NAD+ stand for?
Nicotinamide adenine dinucleotide
## Footnote
NAD+ is the oxidized form of NADH.
119
What is the oxidized form of NADH?
NAD+
## Footnote
NAD+ can accept electrons and become reduced to NADH.
120
What is the reduced form of Nicotinamide?
Nicotinamide
## Footnote
The reduced form of Nicotinamide is part of the NADH molecule.
121
What does the transformation of NAD+ to NADH involve?
Incorporation of 2 electrons and 1 proton from 2 hydrogen atoms
## Footnote
This transformation releases a proton.
122
What is a redox reaction?
A reaction where one partner is oxidized and the other is reduced
## Footnote
In redox reactions, electrons are transferred between molecules.
123
In a redox reaction, what happens to the electron donor?
It becomes oxidized
## Footnote
Oxidation means losing an electron.
124
In a redox reaction, what happens to the electron acceptor?
It becomes reduced
## Footnote
Reduction means gaining an electron.
125
What are two other types of electron carriers besides NADH?
NADPH and FADH2
## Footnote
These carriers also play roles in cellular respiration and metabolism.
126
How are electrons captured for ATP production?
From food and passed on to mitochondria
## Footnote
This process is essential for energy production in cells.
127
True or False: The transformation from NAD+ to NADH is irreversible.
False
## Footnote
The transformation is reversible.
128
What process was proposed by Peter Mitchell around 1960?
CHEMIOSMOSIS
## Footnote
Chemiosmosis explains how energy is harvested from electrons to produce ATP.
129
How can energy be stored in the process of chemiosmosis?
In a transmembrane proton (H*) gradient
## Footnote
This gradient is essential for ATP synthesis.
130
What is the relationship between the establishment of the H+ gradient and ATP synthesis?
They are separate processes
## Footnote
The Ht gradient is established independently of ATP production.
131
What accompanies the directional movement of H+ ions across the membrane?
A chain of reactions involved with electron transport
## Footnote
This chain is crucial for generating the Ht gradient.
132
What is an essential requirement for chemiosmosis?
Intact membranes
## Footnote
Membranes are necessary for both electron transport and ATP synthesis.
133
In which cellular organelles are electron transport and ATP synthesis localized?
Inner membranes of mitochondria and chloroplasts
## Footnote
These organelles play key roles in energy conversion.
134
What is the result of ADP + P in the process of chemiosmosis?
ATP
## Footnote
This reaction is catalyzed by ATP synthase.
135
What high concentration area is found in the intermembrane space of mitochondria?
High H+ concentration
## Footnote
This gradient is crucial for driving ATP synthesis.
136
Fill in the blank: The process of chemiosmosis explains how we get from _______ energy to ATP production.
[redox]
## Footnote
Redox reactions are essential for generating the electrons used in the electron transport chain.
137
What is the role of ATP synthase in chemiosmosis?
Catalyzes the conversion of ADP + P to ATP
## Footnote
ATP synthase utilizes the H+ gradient to drive ATP production.
138
True or False: The H+ gradient is established as a result of ATP synthesis.
False
## Footnote
The Ht gradient is established independently of ATP synthesis.
139
What is the role of NADH in the electron transport chain?
NADH is used in oxidation-reduction (REDOX) reactions to transfer H+ with electrons in the electron transport chain.
## Footnote
NADH carries electrons from food to the electron transport chain.
140
What gradient is used to produce ATP in the electron transport chain?
H+ gradient.
## Footnote
The H+ gradient is created by the unidirectional release of protons into the intermembrane space.
141
Fill in the blank: The first protein complex in the electron transport chain accepts electrons from _______.
NADH.
## Footnote
NADH is derived from food and carries electrons to the first protein complex.
142
What is produced at the end of the electron transport chain?
Water.
## Footnote
Water is produced when oxygen acts as the electronegative atom in the final protein complex.
143
True or False: The electron transport chain requires oxygen.
True.
## Footnote
Oxygen is necessary for the third protein complex in the chain.
144
What mechanism is used by ATP synthase to generate ATP?
Chemiosmosis.
## Footnote
Protons move through ATP synthase, facilitating the conversion of ADP to ATP.
145
What is the function of the intermembrane space in the electron transport chain?
It serves as the area where protons are released, creating an electrochemical gradient.
## Footnote
The intermembrane space is located between the outer and inner mitochondrial membranes.
146
List the components involved in the initial step of the electron transport chain.
* NADH
* Protein complex
* Electrons
* Protons
## Footnote
The initial step involves NADH transferring electrons to a protein complex, which releases protons.
147
What is the role of cytochrome in the electron transport chain?
Cytochrome participates in the transfer of electrons between protein complexes.
## Footnote
Cytochromes are part of the protein complexes that facilitate electron movement.
148
Fill in the blank: The electrochemical gradient created by the electron transport chain is primarily due to the movement of _______.
Protons.
## Footnote
Protons are captured from the mitochondrial matrix and released into the intermembrane space.
149
What is the mitochondrial matrix?
The space inside the inner mitochondrial membrane.
## Footnote
The mitochondrial matrix contains enzymes for the citric acid cycle and other metabolic processes.
150
What is cellular respiration?
Metabolic process with which an organism obtains energy by oxidizing nutrients and releasing waste products
## Footnote
Involves pathways concerned with energy metabolism.
151
What are the main subcellular locations involved in energy metabolism?
Chloroplasts and mitochondria
## Footnote
Photosynthesis occurs in chloroplasts while cellular respiration occurs in mitochondria.
152
What is ATP in the context of cellular respiration?
Biological energy currency
## Footnote
ATP is produced during the energy capture from nutrients.
153
What role do redox reactions play in cellular respiration?
Allow electron carriers to produce ATP via chemiosmosis
## Footnote
Redox reactions are crucial for the transfer of electrons.
154
What is the energy balance of respiration?
Organic molecules + O₂ powers most cellular work
## Footnote
CO₂ and H₂O are waste products of this process.
155
What is a key feature of the metabolic pathways in cellular respiration?
Organised across different subcellular locations and regulated strategically
## Footnote
Regulation occurs at certain steps, such as enzyme function.
156
Fill in the blank: Cellular respiration occurs in _______.
mitochondria
157
True or False: Photosynthesis and cellular respiration occur in the same organelle.
False
## Footnote
Photosynthesis occurs in chloroplasts, while cellular respiration occurs in mitochondria.
158
What are the three stages of cellular respiration?
Glycolysis, Krebs cycle, Electron transport chain
## Footnote
Each stage occurs in a specific subcellular location.
159
Where does glycolysis occur?
Cytosol
## Footnote
Glycolysis is the first stage of cellular respiration.
160
What is the primary function of glycolysis?
To break down glucose to capture energy
## Footnote
This process yields ATP and electrons.
161
What type of phosphorylation occurs during glycolysis?
Substrate-level phosphorylation
## Footnote
This process directly generates ATP.
162
What are the products of glycolysis?
ATP and NADH
## Footnote
NADH carries electrons generated during glycolysis.
163
Which electron carrier is involved in glycolysis?
NADH
## Footnote
NADH is produced during redox reactions in glycolysis.
164
Fill in the blank: Glycolysis breaks down _______ to produce pyruvate.
Glucose
## Footnote
Pyruvate is the end product of glycolysis.
165
True or False: Glycolysis occurs in the mitochondria.
False
## Footnote
Glycolysis occurs in the cytosol, not in the mitochondria.
166
What are the three stages of respiration?
Glycolysis, Citric Acid Cycle, Electron Transport Chain
## Footnote
Respiration can be divided into these three main stages.
167
What pathway follows glycolysis?
Citric Acid Cycle
## Footnote
Also known as the Kreb's cycle or tricarboxylic (TCA) cycle.
168
Where does the Citric Acid Cycle occur?
Mitochondrion
## Footnote
The Citric Acid Cycle takes place within the mitochondrion.
169
What does the Citric Acid Cycle yield?
Energy in the form of ATP and electrons carried by NADH and FADH2
## Footnote
It is essential for energy production.
170
What is another name for the Citric Acid Cycle?
Kreb's Cycle or Tricarboxylic (TCA) Cycle
## Footnote
These names refer to the same biochemical pathway.
171
What type of phosphorylation occurs in the Citric Acid Cycle?
Substrate-level phosphorylation
## Footnote
This process is part of the energy yield in the cycle.
172
Fill in the blank: The Citric Acid Cycle is also known as the _______.
Kreb's Cycle
## Footnote
It is named after Hans Krebs, who identified the cycle.
173
True or False: The Citric Acid Cycle occurs in the cytoplasm.
False
## Footnote
The cycle occurs in the mitochondrion, not the cytoplasm.
174
What are the electron carriers produced by the Citric Acid Cycle?
NADH and FADH2
## Footnote
These carriers play a crucial role in the electron transport chain.
175
What are the three stages of cellular respiration?
1. Glycolysis
2. Citric acid cycle
3. Oxidative phosphorylation
## Footnote
Glycolysis can occur in the absence of oxygen, while the citric acid cycle and oxidative phosphorylation require oxygen.
176
What molecules carry electrons during cellular respiration?
NADH and FADH
## Footnote
These electron carriers are crucial for transferring energy to the electron transport chain.
177
Where does oxidative phosphorylation occur?
In the mitochondria
## Footnote
This stage generates ATP using energy from electrons donated to the electron transport chain.
178
What is the role of the electron transport chain in oxidative phosphorylation?
To generate ATP by transferring electrons
## Footnote
The electrons move through the chain and help create a proton gradient used for ATP synthesis.
179
What type of respiration does glycolysis represent?
Anaerobic respiration
## Footnote
Glycolysis can occur without oxygen, unlike the citric acid cycle and oxidative phosphorylation.
180
What are the two pathways that require oxygen for cellular respiration?
1. Citric acid cycle
2. Oxidative phosphorylation
## Footnote
These processes are part of aerobic respiration and occur in the mitochondria.
181
What is substrate-level phosphorylation?
A method of generating ATP directly in glycolysis and the citric acid cycle
## Footnote
This process does not involve the electron transport chain.
182
What is the main product of oxidative phosphorylation?
ATP
## Footnote
ATP is generated as a result of the electron transport chain and chemiosmosis.
183
True or False: The citric acid cycle can occur without oxygen.
False
## Footnote
The citric acid cycle requires oxygen to proceed.
184
What is glycolysis?
A metabolic pathway that converts glucose into pyruvate, producing ATP and NADH in the process.
## Footnote
Glycolysis occurs in the cytoplasm and is the first step of cellular respiration.
185
What are the two main phases of glycolysis?
Energy investment phase and energy payoff phase.
## Footnote
These phases refer to the initial energy input required and the subsequent energy output generated.
186
What happens during the energy investment phase of glycolysis?
2 ATP are used.
## Footnote
This phase requires energy input to initiate the glycolytic process.
187
What is produced during the energy payoff phase of glycolysis?
4 ATP and 2 NADH are formed.
## Footnote
The payoff phase captures energy, resulting in a net gain of ATP.
188
What is the net gain of ATP in glycolysis?
2 ATP.
## Footnote
This is calculated by subtracting the 2 ATP used in the investment phase from the 4 ATP formed.
189
What is the role of NAD+ in glycolysis?
It is reduced to NADH, capturing electrons and protons.
## Footnote
NADH is essential for later stages of cellular respiration.
190
What are the end products of glycolysis?
2 Pyruvate, 2 NADH, and 2 H2O.
## Footnote
These products are crucial for the next steps in cellular respiration.
191
Fill in the blank: In glycolysis, the energy invested is _______.
2 ATP.
192
Fill in the blank: The process of glycolysis converts glucose into _______.
2 Pyruvate.
193
True or False: The energy investment phase of glycolysis results in a net gain of ATP.
False.
## Footnote
The investment phase requires ATP input, while the payoff phase generates ATP.
194
What is the significance of the 'rock or bump' analogy in glycolysis?
It illustrates the need for energy input to overcome obstacles in the pathway.
## Footnote
This analogy helps explain the concept of the investment phase.
195
What is the chemical formula for glucose?
C6H12O6
196
What is the first step of glycolysis?
Commits glucose to the pathway and needs energy in the form of ATP
197
What is the role of ATP in the first step of glycolysis?
Provides energy to add a phosphate group to glucose
198
Which enzyme is responsible for adding a phosphate group in glycolysis?
Kinase
199
What type of phosphorylation is used to generate ATP in glycolysis?
Substrate phosphorylation
200
What must happen to glucose before ATP can be harvested in glycolysis?
A phosphate group must be added to glucose
201
What is the key focus of the glycolysis pathway?
How chemical energy is harvested and how phosphate groups are moved to produce ATP
202
True or False: Glycolysis starts with a 5-carbon molecule.
False
203
Fill in the blank: Glycolysis requires an initial investment of _______ to add a phosphate group to glucose.
ATP
204
What happens to the energy within chemical bonds during glycolysis?
It is shifted around to harvest ATP in the payoff phase
205
What happens in Step 2 of glycolysis?
The chemical bonds shift to form an isomer molecule
206
What is the function of isomerase?
Converts a molecule from one isomer to another
207
What does glycolysis require when it incorporates another phosphate group?
Energy in the form of ATP
208
What is the function of a kinase enzyme?
Adds phosphate
209
What is the primary function of Step 4 in glycolysis?
Splits the 6-carbon molecule into two smaller 3-carbon molecules
## Footnote
Enzyme type involved is lyase.
210
What occurs during Step 5 of glycolysis?
Converts one molecule, yielding 2 identical 3-carbon molecules.
211
What is the first redox reaction in glycolysis?
Step 6, where electrons are captured and carried by NADH
## Footnote
This step involves the conversion of a substrate through the action of dehydrogenase enzymes.
212
What role do dehydrogenase enzymes play in glycolysis?
They oxidize a substrate by reducing an electron acceptor
## Footnote
This process is crucial for the transfer of electrons during glycolysis.
213
How many NAD molecules are involved in glycolysis?
2 NAD
## Footnote
NAD is essential for the redox reactions occurring within glycolysis.
214
What is the first payoff reaction in glycolysis?
Step 7
## Footnote
Step 7 is significant as it marks the first generation of ATP in the glycolytic pathway.
215
What happens to a phosphate group during the first payoff reaction?
It comes from the 3-carbon molecule and gets added to ADP to make ATP
## Footnote
This process is crucial for energy production in the cell.
216
What enzyme is involved in the first payoff reaction of glycolysis?
Kinase
## Footnote
Kinases are enzymes that catalyze the transfer of phosphate groups.
217
What is the purpose of Step 8 in glycolysis?
Moves the chemical bonds around in preparation for another substrate phosphorylation
218
What happens in step 9 of glycolysis?
Step 9 cleaves off water
## Footnote
This step is crucial for the conversion of 2-phosphoglycerate to phosphoenolpyruvate.
219
What type of enzyme is Enolase?
Enolase is a hydro-lyase type enzyme
## Footnote
Hydro-lyases are enzymes that cleave bonds by the addition of water.
220
What is the final step in glycolysis?
The final step in glycolysis takes the phosphate group to make more ATP and yields the end product: pyruvate.
221
How many pyruvate molecules are produced at the end of glycolysis?
Two pyruvate molecules.
222
What happens in step 4 of glycolysis?
Step 4 splits the 6-carbon molecule into two 3-carbon molecules.
223
In the final step of glycolysis, what is taken to produce ATP?
A phosphate group.
224
Fill in the blank: The end product of glycolysis is _______.
pyruvate.
225
Where does glycolysis occur in the cell?
In the cell's cytosol
## Footnote
Glycolysis is the first step in cellular respiration and occurs in the cytoplasm of the cell.
226
Where does the citric acid cycle take place?
In the mitochondrion
## Footnote
The citric acid cycle, also known as the Krebs cycle, takes place in the mitochondrial matrix.
227
What molecule is produced from pyruvate before entering the citric acid cycle?
Acetyl coenzyme A (acetyl CoA)
## Footnote
Acetyl CoA is formed by the oxidation of pyruvate, which involves the removal of carbon dioxide.
228
What happens to NAD+ during the preparation of pyruvate for the citric acid cycle?
It is reduced to form NADH
## Footnote
This reduction occurs when pyruvate is oxidized and carbon dioxide is released.
229
What is the process of preparing pyruvate for the citric acid cycle also known as?
The link reaction
## Footnote
The link reaction connects glycolysis to the citric acid cycle.
230
True or False: The link reaction proceeds in the absence of oxygen.
False
## Footnote
The link reaction requires oxygen to occur.
231
What must happen to pyruvate before it can enter the citric acid cycle?
It must be oxidized and have carbon dioxide cleaved off
## Footnote
This oxidation is necessary for the conversion to acetyl CoA.
232
Fill in the blank: The molecule that enters the citric acid cycle after the link reaction is _______.
Acetyl coenzyme A
## Footnote
Acetyl CoA carries two carbons into the citric acid cycle.
233
What is the role of coenzyme A in the preparation of pyruvate?
It is incorporated into the molecule to form acetyl CoA
## Footnote
Coenzyme A is essential for the transport of acetyl groups into the citric acid cycle.
234
What is another name for the citric acid cycle?
Tricarboxylic acid (TCA) cycle or Krebs cycle
235
What molecule is essential for the citric acid cycle to proceed?
2 carbon acetyl co A
236
What is important to recognize in the citric acid cycle?
What goes in and out of this pathway
237
What can help in creating a net equation for the citric acid cycle?
A picture illustrating the inputs and outputs
238
What does one cycle of the citric acid cycle produce with 1 Acetyl CoA?
3 NADH, 1 FADH2, 1 ATP
## Footnote
This represents the energy carriers generated in a single cycle.
239
What does two cycles of the citric acid cycle produce with 2 Acetyl CoA?
6 NADH, 2 FADH2, 2 ATP
## Footnote
This accounts for the energy carriers generated when processing the equivalent of one glucose molecule.
240
What is generated during the link step when converting Pyruvate to Acetyl CoA?
1 NADH
## Footnote
This happens twice for each glucose molecule, contributing to the total NADH count.
241
What is the total yield of NADH, FADH2, and ATP from aerobic respiration through glycolysis and the citric acid cycle?
8 NADH, 2 FADH2, 2 ATP
## Footnote
This includes contributions from both glycolysis and the citric acid cycle.
242
What is the initial reaction in the citric acid cycle?
A 2-carbon Acetyl CoA links with a 4-carbon molecule to form a 6-carbon molecule
## Footnote
This initiates the cycle by combining Acetyl CoA with oxaloacetate.
243
What happens to the 2 carbons that enter the citric acid cycle from Acetyl CoA?
2 carbons escape as CO2
## Footnote
This is part of the process of oxidizing citrate back to oxaloacetate.
244
How many times does the citric acid cycle occur for one glucose molecule?
Twice
## Footnote
Each glucose molecule produces two pyruvate molecules, leading to two cycles.
245
In each cycle of the citric acid cycle, how many electrons are captured in NADH and FADH2?
3 NADH and 1 FADH2
## Footnote
These carriers are crucial for the electron transport chain.
246
Fill in the blank: The citric acid cycle oxidizes _______ to oxaloacetate.
citrate
## Footnote
This oxidation is a key part of the cycle's function.
247
True or False: The citric acid cycle is a linear pathway.
False
## Footnote
It is a cyclic pathway that continuously recycles 4-carbon molecules.
248
What is the primary function of the electron transport chain?
To oxidize electron carriers and pass electrons to oxygen to form water
## Footnote
This process creates a negative delta G, indicating free energy is available for work.
249
What is the result of passing electrons to oxygen in the electron transport chain?
Formation of water
## Footnote
This process is crucial for maintaining the flow of electrons through the chain.
250
What does a negative delta G indicate in the context of the electron transport chain?
Availability of free energy
## Footnote
This free energy is utilized to pump protons across the membrane.
251
How do protons move across the membrane during oxidative phosphorylation?
Against their proton gradient
## Footnote
This movement is powered by the free energy generated in the electron transport chain.
252
What are the three transmembrane protein complexes involved in the electron transport chain?
Complex I, Complex II, Complex III
## Footnote
These complexes facilitate the transfer of electrons and the pumping of protons.
253
What are the names of the two smaller and more movable enzymes in the electron transport chain?
Coenzyme Q and cytochrome c
## Footnote
These enzymes assist in the transfer of electrons between the protein complexes.
254
What is the final step of the process in the electron transport chain?
Protons move through ATP synthase
## Footnote
This movement generates energy for ATP production.
255
How many electrons enter the electron transport chain per NADH molecule?
2 electrons
## Footnote
Each NADH also contributes 1 proton to the chain.
256
What is produced from the oxidation of one oxygen molecule in the electron transport chain?
One water molecule
## Footnote
This occurs as electrons are transferred to oxygen.
257
Fill in the blank: For each NADH molecule, _____ electrons and 1 proton enter the electron transport chain.
2
## Footnote
This highlights the contribution of NADH to the electron transport process.
258
What is the overall purpose of ATP synthase in the electron transport chain?
To generate ATP
## Footnote
ATP synthase uses the energy from protons moving down their electrochemical gradient.
259
True or False: All electron carriers are oxidized in the electron transport chain.
True
## Footnote
This is a key aspect of the electron transport chain's function.
260
How many electrons reach the electron transport chain per one glucose molecule?
6 electrons
## Footnote
This is derived from the breakdown of glucose, producing 2 NADH molecules for each glucose.
261
What is produced during glycolysis?
2 ATP and 2 electrons
## Footnote
Glycolysis is the first step in glucose metabolism.
262
What cycle follows glycolysis in glucose metabolism?
Citric acid cycle
## Footnote
Also known as the Krebs cycle.
263
How many ATP are produced in the citric acid cycle?
2 ATP
## Footnote
The citric acid cycle also produces electrons.
264
What is the role of the electron transport chain?
Pumps protons across the membrane to produce ATP
## Footnote
This process utilizes electrons captured from previous stages.
265
What are the final products of glucose oxidation?
Carbon dioxide and water
## Footnote
This occurs after the complete breakdown of glucose.
266
What happens to the free energy when electrons move from glucose to oxygen?
Increases in free energy, resulting in a large delta G
## Footnote
This is due to the difference in electronegativity between glucose and oxygen.
267
How many protons are generally thought to be needed to produce 1 ATP molecule?
3.3 protons
## Footnote
This is an average estimate and remains a debated topic.
268
Does glycolysis require oxygen?
No, it does not require oxygen
## Footnote
Glycolysis can occur during both aerobic and anaerobic respiration.
269
What happens during anaerobic exercise when oxygen supply is limited?
Glycolysis supplies energy and fermentation occurs
## Footnote
The citric acid cycle and electron transport chain cannot proceed without sufficient oxygen.
270
Fill in the blank: Glycolysis occurs during both _______ and anaerobic respiration.
aerobic
## Footnote
This allows for energy production in various conditions.
271
What is the energy yield of fermentation per glucose molecule?
2 ATP
## Footnote
Fermentation produces significantly less ATP compared to oxidative phosphorylation.
272
What are the two types of fermentation mentioned?
* Alcohol fermentation
* Lactic acid fermentation
## Footnote
These two processes differ based on the end products and the organisms involved.
273
What is the main product of alcohol fermentation?
Ethanol
## Footnote
Ethanol is produced by microbes like yeast during fermentation.
274
What is the main product of lactic acid fermentation?
Lactate
## Footnote
Lactic acid is produced by animals during fermentation.
275
What is the role of NAD+ in fermentation?
NAD+ regeneration
## Footnote
NAD+ is regenerated during fermentation to allow glycolysis to continue.
276
How many ATP are produced by oxidative phosphorylation compared to fermentation?
32 ATP
## Footnote
Oxidative phosphorylation produces significantly more ATP than fermentation.
277
What is the basic principle of oxidative phosphorylation?
Chemiosmosis
## Footnote
Chemiosmosis is the process that drives ATP synthesis in oxidative phosphorylation.
278
True or False: Fermentation occurs in the presence of oxygen.
False
## Footnote
Fermentation occurs in anaerobic conditions (no or low oxygen).
279
Fill in the blank: Fermentation produces _______ ATP per glucose compared to oxidative phosphorylation.
2
## Footnote
This highlights the lower efficiency of fermentation in energy production.
280
What is the significance of mitochondria in relation to energy balance?
Favorable change for energy balance
## Footnote
The evolution of mitochondria allowed for more efficient ATP production through oxidative phosphorylation.
281
What is the initial substrate for glycolysis?
Glucose
## Footnote
Glycolysis begins with the breakdown of glucose to produce pyruvate.
282
What are the final products of glycolysis?
* 2 Pyruvate
* 2 NADH
* 2 ATP
## Footnote
Glycolysis results in the production of these molecules before fermentation occurs.
