Bioenergetics Flashcards
1
Q
is the study of the transformation, distribution, and utilization of energy by living organisms.
A
Bioenergetics
2
Q
Bioenergetics includes:
A
– radiant energy of sunlight used in photosynthesis
– electrical energy of nerve impulses
– mechanical energy of muscle contractions
3
Q
The bioenergetics of a cell can be compared to the energetics of a
A
Manufacturing plant
4
Q
Manufacturing plant energetics
A
- Energy is delivered as electricity, coal, oil, gas, etc.
- Electricity, coal, oil, gas, etc., is converted to mechanical energy
- Mechanical energy converts raw materials into products
5
Q
Animal cell bioenergetics
A
- Energy is delivered as reduced carbon atoms
- Energy in reduced carbon atoms is converted to high-energy phosphate bonds
- High-energy phosphate bonds are used to do the work of the cell
6
Q
Plant cell bioenergetics
A
- Energy is delivered as sunlight
- Sunlight is converted to chemical energy
- High-energy phosphate bonds are used to do the work of the cell
7
Q
The sum of all chemical reactions that occur within a living organism is defined as
A
Metabolism
8
Q
Metabolism can be subdivided into two contrasting categories:
A
- Anabolism
- Catabolism
9
Q
is the process by which simple substances are synthesized (built up) into complex substances.
A
Anabolism
10
Q
usually involve carbon reduction and consume cellular energy.
A
Anabolic reactions
11
Q
is the process by which complex substances are broken down into simpler substances.
A
Catabolism
12
Q
usually involve carbon oxidation and produce energy for the cell.
A
Catabolic reactions
13
Q
will provide the source of energy we need for all our activities such as thinking, moving, breathing, walking, talking, etc.
A
Metabolism
14
Q
is also needed for many of the cellular processes such as protein synthesis, DNA replication, RNA transcription and transport across the membrane, etc.
A
Energy
15
Q
Usually energy is released in these reactions
A
Catabolism
16
Q
Usually require energy
A
Anabolism
17
Q
Series of consecutive biochemical reactions used to convert a starting material into an end product
A
Metabolic pathway
18
Q
Two types of metabolic pathways
A
Linear
Cyclic
19
Q
The major pathways for all forms of life are similar:
A
Linear pathway: A B C D
Cyclic pathway: A B D C
20
Q
Cells segregate many of their metabolic reactions into specific, subcellular locations.
A
Procaryotes
Eucaryotes
21
Q
are cells WITHOUT internal membrane-bound bodies.
A
Procaryotes
22
Q
The anabolic processes of DNA and RNA synthesis in these cells are localized in the nuclear material, whereas most other metabolic reactions are spread throughout the cytoplasm
A
Procaryotes
23
Q
Contain internal, membrane-bound bodies called ORGANELLES
A
Eucaryotes
24
Q
It is within the organelles that many specific metabolic processes occur
A
Eukaryotes
25
Most of the DNA and RNA syntheses are localized in the NUCLEUS
Eukaryotic cell
26
Anabolism of proteins takes place in the RIBOSOMES, whereas that of carbohydrates and lipids occurs primarily in the cytoplasm
Eukaryotic cell
27
There are a variety of specialized ____________ organelles within a eukaryotic cell
Catabolic
28
Digestive enzymes
Lysosome
29
Provides most of the energy for a cell
Mitochondria
30
consume most of the oxygen that is inhaled and produce most of the carbon dioxide that is exhaled by the lungs.
Mitochondria
31
knowledge cell structure is essential to the understanding of
Metabolism
32
Single compartment organism
Prokaryotic cell
33
No nucleus -- found only in bacteria
Prokaryotic cell
34
Single circular DNA molecule present near center cell called NUCLEOID
Prokaryotic cell
35
Multi-compartment cell
Eukaryotic cell
36
DNA is present in the membrane enclosed NUCLEUS
Eukaryotic cell
37
Cell is compartmentalized into cellular ORGANELLES
Eukaryotic cell
38
~1000 times larger than bacterial cells
Eukaryotic cell
39
DNA replication and RNA synthesis
Nucleus
40
Cellular boundary
Plasma membrane
41
The WATER-BASED material of a eukaryotic cell
Cytoplasm
42
Generate most of the energy needed for cell
Mitochondria
43
Contain HYDROLYTIC ENZYMES needed for cell rebuilding, repair, and degradation
Lysosome
44
Sites for protein synthesis
Ribosomes
45
Mitochondria: ____________: Permeable to small molecules: 50% lipid, 50% protein
Outer membrane
46
Mitochondria: ____________: Highly permeable to most substances: 20% lipid, 80% protein
Inner membrane
47
folded to increase surface area
Inner membrane
48
Synthesis of ATP occurs
Mitochondria
49
Important Intermediate Compounds in Metabolic Pathways
Adenosine Phosphates (AMP, ADP, ATP, cAMP)
50
Cyclic structure of phosphate
Cyclic monophosphate (cAMP)
51
Structural component fo RNA
Adenosine monophosphate (AMP)
52
Key components of metabolic pathways
Adenosine diphosphate
Adenosine triphosphate
53
Phosphate groups are connected to __________________ by strained bonds which require less than normal energy to hydrolyze them
Adenosine monophosphate (AMP)
54
ATP + H2O ➡️ ADP + PO43- + Energy
ADP + H2O ➡️ AMP + PO43- + Energy
Overall Reaction: ATP + 2H2O ➡️ AMP + 2 PO43- + Energy
55
The net energy produced in these reactions is used for
Cellular reactions
56
In cellular reactions ____ functions as both a source of a PHOSPHATE GROUP and a source of ENERGY.
Adenosine triphosphate (ATP)
57
Involved in carbohydrate metabolism
Uridine triphosphate (UTP)
58
Involved in protein and carbohydrate metabolism
Guanosine triphosphate (GTP)
59
involved in lipid metabolism
Cytidine triphosphate (CTP)
60
FAD
Flavin Adenine Dinucleotide
61
A coenzyme required in numerous metabolic REDOX reactions
FAD
62
is the ACTIVE form - accepts and donates electrons
Flavin subunit
63
is a reduced form of ribose sugar
Ribitol
64
A typical cellular reaction in which FAD serves as oxidizing agent involves conversion of an
Alkane to an alkene
65
is oxidized form
FAD
66
is reduced form
FADH2
67
In enzyme reactions FAD goes back and forth (equilibrium)
from oxidized to reduced form
68
NAD+: coenzyme
NADH is reduced form
69
NAD+ 3 subunit structure
Nicotinamide - ribose - ADP
70
NAD+ 6 subunit structure
Nicotinamide - ribose - phosphate - phosphate - ribose - adenine
71
A typical cellular reaction in which NAD+ serves as the oxidizing agent is the oxidation of a
Secondary alcohol to give a ketone
72
A derivative of vitamin b
Coenzyme A
73
Coenzyme A 3 subunit structure
2-Aminoethanethiol - pantothenic acid - phosphorylated ADP
74
Coenzyme A 6 subunit structure
2-Aminoethanethiol - pantothenic acid - phosphate - phosphate - phosphorylated ribose - adenine
75
Active form of coenzyme A is the __________________ in the ethanethiol subunit of the coenzyme
Sulfhydryl group (-SH group)
76
Acetylated
Acetyl-CoA
77
Metabolic intermediate compounds can be classified into three groups based on their functions
1. Intermediates for the storage of energy and transfer of PHOSPHATE GROUPS
2. Intermediates for the transfer of ELECTRONS in metabolic redox reactions
3. Intermediates for the transfer of ACETYL GROUPS
78
Several phosphate containing compounds found in metabolic pathways are known as
High energy compounds
79
High energy compounds have greater _________________ than a typical compound
Free energy of hydrolysis
79
They contain at least one REACTIVE BOND -- called STRAINED BOND
High energy compounds
80
Energy to break these bonds is less than a normal bond -- __________ of high energy compounds give more energy than normal compounds
Hydrolysis
81
More ________ the free energy of hydrolysis, greater the bond strain
Negative
82
Typically the free energy release is greater than ______________ (indicative of bond strain)
6.0 kcal/mole
83
Strained bonds are represented by sign
~ (squiggle bond)
84
are organelles found in HIGHER PLANTS and contain an electron-transport system that is responsible for the anabolic redox reactions in photosynthesis.
Chloroplasts
85
often called the “powerhouses” of the cell, are the sites for most of the catabolic redox reactions.
Mitochondria
86
To move electrons from one place to
another, the cell uses a set of
Redox coenzymes
87
act as temporary storage places for electrons.
Redox coenzymes
88
A very important function of these redox
coenzymes is to carry electrons to the
mitochondrial electron-transport system
89
As the coenzymes are oxidized, molecular oxygen is
Reduced
90
O2
Molecular oxygen
91
plays a critical role in energy production.
Molecular oxygen (O2)
92
Acts as the FINAL RECEPTACLE for electrons in the mitochondrial electron-transport system.
Molecular oxygen (O2)
93
is the best way to produce energy for most cells.
Aerobic metabolism
94
Some REDUCED products of molecular oxygen (O2) are
dangerous
95
ROS
Reactive Oxygen Species
96
can react with and destroy many vital cell molecules
Reactive Oxygen Species (ROS)
97
A 2-electron redox reaction occurs and makes
Hydrogen peroxide
98
Most dangerous ROS are formed if redox
reactions involve only
1 electron
99
is formed when molecular oxygen is
reduced with one electron, O2-
Superoxide
100
The MOST DANGEROUS ROS is the ________________, a neutral hydroxide (OH) that can react with almost anything in the cell.
Hydroxyl radical
101
Cells need an ENERGY DELIVERY SYSTEM. Most cellular energy is produced in the MITOCHONDRIA, but this energy must be transported throughout the cell. Such a delivery system must carry relatively LARGE AMOUNTS OF ENERGY and be easily accessible to cellular reactions
High-energy phosphate bonds
102
Phosphate Anhydride Bond
Phosphoanhydride bond
103
When the phosphoanhydride bond is broken, the phosphates separate rapidly, and __________ is released
Energy
104
is an important component of the nucleotide triphosphates, the most
important of which is adenosine
triphosphate (ATP).
Phosphate anhydride bond
105
plays an important role in all cells
ATP
106
It functions by storing and transporting the energy in its high-energy phosphate bonds to the places in the cell where energy is needed.
ATP
106
s a common intermediary in energy metabolism.
ATP
107
Phosphorylation
Energy conversion
108
Energy is stored in PHOSPHATE ANHYDRIDE BONDS through two biological processes:
1. Substrate-level phosphorylation
2. Oxidative phosphorylation
109
is the process whereby ENERGY DERIVED FROM OXIDATION is used to form high-energy phosphate bonds on various biochemical molecules (substrates).
Substrate-level phosphorylation
110
Substrate-level phosphorylation is found most commonly in the CATABOLISM OF CARBOHYDRATES – that is,
Glycolysis
111
Under _______________, substrate-
level phosphorylation may be the cell’s
principal means of forming ATP.
Anaerobic conditions
112
Is a process that directly uses ENERGY FROM REDOX REACTIONS to form ATP.
Oxidative phosphorylation
113
This process occurs in the mitochondria and depends on the mitochondrial electron-transport system.
Oxidative phosphorylation
114
is the process by which energy from the sun is CONVERTED TO CHEMICAL ENERGY that is stored in chemical bonds.
Photosynthesis
115
performed by a variety of organisms, both EUKARYOTIC and PROKARYOTIC
Photosynthesis
116
causes the electrons to become more energetic, so that they can reduce NADP+.
Light energy
117
The breakdown of glucose into two pyruvic acid molecules
Glycolysis
118
is the formation of glycogen from glucose
Glycogenesis
119
is the breakdown of glycogen to glucose
Glycogenolysis
120
is the formation of glucose from amino acids and glycerol
Gluconeogenesis
121
is the formation of lipids from glucose and amino acids
Lipogenesis
122
The first phase is glycolysis, which produces
2 ATP
2 NADH
2 Pyruvic acid molecules
123
The second phase is the conversion of theTWO PYRUVIC ACID molecules into TWO MOLECULES OF ACETYL-CoA. These reactions also produce
2 NADH
2 Carbon dioxide molecules
124
The third phase is the citric acid cycle, which produces
2 ATP
6 NADH
2 FADH2
4 carbon dioxide molecules
125
The fourth phase is the electron-transport chain. The high-energy electron-transport chain and are used in the synthesis of
ATP and water
126
Stage 1
Digestion of carbohydrates
127
Stage 2
Glycolysis
128
Begins in the mouth where salivary amylase BREAKS DOWN POLYSACCHARIDES to smaller polysaccharides (dextrins), maltose, and some glucose.
Stage 1: Digestion of carbohydrates
129
Continues in the small intestine where pancreatic amylase HYDROLYZES DEXTRINS to maltose and glucose.
Stage 1: Digestion of carbohydrates
130
Hydrolyzes maltose, lactose, and sucrose to MONOSACCHARIDES, mostly glucose, which enter the bloodstream for transport to the cells.
Stage 1: Digestion of.carbohydrates
131
Glucose + Glucose
Maltose
132
Galactose + Glucose
Lactose
133
Glucose + Fructose
Sucrose
134
Is a metabolic pathway that uses glucose, a digestion product.
Glycolysis
135
Degrades six-carbon glucose molecules to three-carbon pyruvate molecules
Glycolysis
136
Is an anaerobic (no oxygen) process.
Glycolysis
137
In reactions 1-5 of glycolysis
Glycolysis: energy-investment
138
In reactions 6-10 of glycolysis
Glycolysis-energy production
139
In reactions 1-5 of glycolysis,
- Energy is required to ADD PHOSPHATE GROUPS to glucose
140
In reactions 1-5 of glycolysis,
Glucose is CONVERTED to 2 THREE-CARBON molecules
141
Glycolysis: energy investment (enzyme)
1. Hexokinase
2. Phosphoglucoisomerase
3. Phosphofructokinase
4. Fructose-1, 6-bisphosphate aldolase
5. Triosephosphate isomerase
142
Glycolysis: energy production (enzyme)
6. Glyceraldehyde-3-phosphate-dehydrogenase
7. Phosphoglycerate kinase
8. Phosphoglycerate mutase
9. Enolase
10. Pyruvate kinase
143
In reactions 6-10 of glycolysis, energy is generated as
- Sugar phosphate are CLEAVED TO TRIOSE phosphates
144
In reactions 6-10 of glycolysis, energy is generated as
4 ATP molecules are PRODUCED
145
add phosphate to GLUCOSE and FUCTOSE-6-PHOSPHATE.
2 ATP
146
are formed in energy-generation by direct transfers of phosphate groups to four ADP
4 ATP
147
There is a NET GAIN of
2 ATP
2 NADH
148
Glycolysis is regulated by
3 enzymes
149
Hexokinase is inhibited by high levels of GLUCOSE-6-PHOSPHATE, which prevents the phosphorylation of glucose
Reaction 1
150
Phosphofructokinase, an ALLOSTERIC ENZYME, is inhibited by high levels of ATP and activated by high levels of ADP and AMP.
Reaction 3
151
Pyruvate kinase, another ALLOSTERIC ENZYME is inhibited by high levels of ATP or acetyl CoA.
Reaction 10
152
In glycolysis, what compound provide phosphate groups for the production of ATP?
Reaction 7
Reaction 10
153
Pyruvate
Aerobic conditions
Anaerobic conditions
154
Pyruvate: aerobic conditions (oxygen present)
Three-carbon pyruvate is DECARBOXYLATED
155
Pyruvate: aerobic conditions (oxygen present)
Two-carbon acetyl CoA and CO2 are PRODUCED
156
Pyruvate: anaerobic conditions (without oxygen)
Pyruvate is REDUCED to lactate
157
Pyruvate: anaerobic conditions (without oxygen)
NADH oxidizes to NAD+ allowing glycolysis to continue.
158
After exercise, a person breathes heavily to repay the oxygen debt and reform PYRUVATE in the
Liver
159
During strenuous exercise,
- Oxygen in the muscles is DEPLETED
- Anaerobic conditions are PRODUCED
- Lactate ACCUMULATES
- Muscle TIRE and become PAINFUL
160
Occurs in ANAEROBIC microorganisms such as YEAST.
Fermentation
161
Decarboxylates pyruvate to ACETALDEHYDE, which is reduced to ETHANOL.
Fermentation
162
Regenerates NAD+ to continue glycolysis
Fermentation
163
Produced during anaerobic conditions
Lactate
164
Reaction series that converts glucose to pyruvate
Glycolysis
165
Metabolic reactions that break down large molecules to smaller molecules + energy.
Catabolic reactions
166
Substances that remove or add H atoms in oxidation and reduction reactions.
Coenzymes
167
