Metabolism Flashcards
(227 cards)
1
Q
What is the first step of glycolysis?
A
Glucose enters the cell and is phosphorylated. A molecule of ATP is invested. The product is 6-glucose phosphate.
2
Q
What is the second step of glycolysis?
A
Glucose 6-phosphate is rearranged to form fructose 6-phosphate.
3
Q
What is the 3rd step of glycolysis?
A
The phosphate group from another ATP is used to produce fructose 1, 6- diphosphate, still a 6 carbon compound (2 ATP are invested at this point.
4
Q
What is the 4th step of glycolysis?
A
An enzyme splits the sugar into 2 3-carbon molecules: dihydroxyacetone phosphate (DHAP) and glyceraldehyde 3-phosphate (GP)
5
Q
What is the 5th step of glycolysis?
A
DHAP is readily converted to GP the reverse reaction may occur.
6
Q
What is the 6th step of glycolysis?
A
The next enzyme converts each GP to another 3-carbon compound 1,3-diphosphoglyceric acid. Because each DHAP molecule can be converted to GP and each GP to 1, 3-diphosphoglyceric acid for each initial molecules of glucose. GP is oxidized by the transfer 2 hydrogen atoms to NAD+ to form NADH. The enzyme couples this reaction with the creation of a high-energy bond between sugar and a phosphate group. The 3 carbon sugar now has 3 phosphate groups.
7
Q
What is the 7th step of glycolysis?
A
The high energy phosphate group is moved to ADP, forming ATP, the first ATP production of glycolysis. Since step 4 all products are doubled, therefore, this step is actually repays the earlier investment of 2 ATP molecules.
8
Q
What is the 8th step of glycolysis?
A
An enzyme relocates the remaining phosphate group of 3-phosphoglyceric acid to form 2-phosphoglyceric acid in preparation for the next step.
9
Q
What is the 9th step og glycolysis?
A
By the loss of a water molecule 2-phosphoglyceric acid is converted into phosphoenolpyruvic acid (PEP). In the process, the phosphate bond is upgraded to a high energy bond.
10
Q
What is the 10th step of glycolysis?
A
The high energy phosphate bond is transferred from PEP to ADP, forming ATP. For each initial glucose molecule, the result of this step is 2 molecules of ATP and 2 molecules of a 3-carbon compound called pyruvic acid.
11
Q
What is another name for glycolysis?
A
Embden-Meyerhof pathway
12
Q
Phosphorylation
A
The transferring of phosphate group from a donor to the recipient molecule.
13
Q
Cellular respiration
A
ATP generating process in which molecules are oxidized and the final electron acceptor comes from outside the cell and is almost always an inorganic molecule.
14
Q
Glycolysis
A
The oxidation of glucose to pyruvic acid, usually the 1st stage in carbohydrate catabolism.
15
Q
Oxidation
A
- the removal of electrons from an atom or molecule, a reaction that often produces energy
- the removal of one or more electrons from a substrate. Protons H+ are often removed with electrons
16
Q
Reduction
A
a molecule has gained one or more electrons
17
Q
Redox reaction
A
- Oxidation and reduction reactions are always coupled; each time a substance is oxidized another is simultaneously reduced.
- oxidation reaction paired with reduction reaction
18
Q
Metabolism
A
The sum of all chemical reactions in an organism
19
Q
Catabolism
A
The breakdown of complex molecules into monomers; provides energy and building blocks for anabolism
20
Q
Anabolism
A
Uses energy and building blocks to build large molecules from monomers.
21
Q
What links catabolic and anabolic reactions?
A
energy, catabolic reactions provide energy for anabolic reactions.
22
Q
Energy+monomers =
A
macromolecule
23
Q
during catabolism macromolecules are being broken down into ___________.
A
monomers and energy
24
Q
How does catabolism release energy ?
A
by the oxidation of molecules
25
Anabolism uses \_\_\_\_\_\_\_\_
energy to synthesize macromolecules that make up the cell
26
ATP stores\_\_\_\_\_\_\_\_\_.
energy
27
Energy is released by __________ of ATP.
hydrolysis
28
ADP + inorganic phosphate+ energy =
ATP
29
ATP - Energy =
ADP and inorganic phosphate
30
What are metabolic pathways determined by?
enzymes which are encoded by genes different genes means different proteins (enzymes being made) = different metabolic pathways
31
Enzymes are encoded by
genes
32
Catabolic reactions transfer energy from
complex molecules to ATP
33
Anabolic reactions transfer energy from
ATP to complex molecules
34
Although microbes can cause disease and food spoilage many metabolic pathways are \_\_\_\_\_\_\_\_\_\_\_\_.
beneficial
35
The pharmaceutical industry uses microbes such as \_\_\_\_\_\_\_\_\_\_\_\_\_\_
bacteria and fungi to make antibiotics
36
vitamins, vaccines, antibiotics, and enzymes are dirived from \_\_\_\_\_\_\_\_\_\_\_\_.
microbial metabolism
37
What is the big picture of the function of an enzyme?
they facilitate metabolic reactions
38
Most living things use __________ to manage energy needs.
ATP
39
Catabolic reactions couple with \_\_\_\_\_\_\_\_\_\_\_\_\_.
ATP synthesis
40
Anabolic reactions couple with \_\_\_\_\_\_\_\_\_.
ATP break down
41
Chemical reactions
Chemical reactions can occur when atoms, ions, and molecules collide
42
Activation energy
Activation energy is needed to disrupt existing bonds, even in spontaneous reactions
43
Reaction rate
Reaction rate is the rate of formation of products from reactants.
44
A reaction rate can be increased by
Enzymes, temperature or pressure
45
Why does a reaction rate increase when pressure is applied to reactants?
The reactants are in closer proximity to each other which increases the likelihood of a reaction occuring
46
Why does a reaction rate increase when temperature is increased?
heat will energize the molecules and cause them to move faster; increasing the chances that the molecules will collide and a reaction will occur.
47
Why do enzymes increase reaction rates?
because they ether bend bonds between molecules allowing substrates to be broken down more easily, or they bring molecules closer together and position them to increase the chances of a chemical reaction.
48
Enzymes help to increase the likeihood of chemical reactions by \_\_\_\_\_\_\_\_\_\_\_\_\_.
reducing the activation energy need elicit a chemical reaction. Enzymes are catalysts.
49
Enzymes
Biological catalysts; specific; not used up in that reaction
50
What are the components of an enzyme?
Apoenzymes, Cofactors, Holoenzymes
51
Coenzyme
an organic cofactor
52
Apoenzyme
inactive protein portion of an enzyme
53
Cofactor/coenzyme
non-protein agent which activates the enzyme by binding to the Apoenzyme.
54
Holoenzyme
whole, complete active enzyme. Made up of apoenzyme and cofactor
55
Examples of Coenzymes
NAD+, NADP+, FAD
56
The names of enzymes usually end in \_\_\_\_\_\_\_\_\_.
-ase
57
enzymes can be grouped into ____ classes
6; according to the type of chemical reaction they catalyze
58
Enzymes within the 6 classes are named after \_\_\_\_\_\_\_\_\_.
the specific types of reactions they assist
59
oxidoreductases
enzymes which are involved in oxidation-reduction reactions; oxygen or hydrogen are gained or lost. ex. cytochrome oxidase, lactate dehydrogenase
60
What are enzymes in oxioreductase class remove hydrogen from substances?
dehydrogenase; those that add electrons to molecular oxygen (O2) are called oxidases
61
Transferase
responsible for transfer of functional groups amino group, acetyl group or phosphate group ex. Acetate kinase, alanine deaminase
62
Hydrolase
responsible for hydrolysis (addition of water) ex. lipase and sucrase
63
Lyase
responsible for removal of groups of atoms without hydrolysis ex. Oxalate decarboxylase and isocitrate lyase
64
Isomerase
Responsible for rearrangement of atoms in a molecule ex. Glucose-phosphate isomerase, alanine racemase
65
Ligase
responsible for joining of 2 molecules (usually using energy from the break down of ATP) ex. Acetyl CoA synthase, DNA ligase
66
How does the mechanism of enzymatic reactions work?
1. An enzyme molecule has an active site where it binds the substrate molecule
2. The reaction between the substrate molecule and enzyme forms a complex and may temporarily alter the active site slightly
3. The enzyme molecule brakes apart the substrate molecule
4. 2 end products result from the reaction and are released from the enzyme.
5. The enzyme molecule remains unchanged and is recycled.
67
What are the factors that influence enzyme activity
1. Temperature
2. pH
3. Substrate concentration
4. Inhibitors
68
Enzymes can become __________ by inappropriate pH or temp.
denatured
69
enzyme activity/ reaction rate increases with temperature until
the enzyme reaches a point where it becomes denatured and can no longer facilitate reactions
70
why are catabolic and anabolic reactions important?
they allow an organism to grow and reproduce by providing energy and the monomers necessary to build macromolecules
71
when glucose is transormed into ATP where do the electrons go?
they will be transferred to oxygen
72
During each chemical reaction in a metabolic pathway there is \_\_\_\_\_\_\_\_\_\_\_.
an enzyme facilitating the reaction
73
What is the energy level of ADP?
low
74
What is the enegy level of ATP?
high; due to the ustable bonds between the phosphate groups
75
energy is stored in the bonds between \_\_\_\_\_\_\_\_.
carbon atoms
76
sunlight is converted into glucose in plants the glucose in plants then \_\_\_\_\_\_\_\_.
powers the biochemical reactions of animals
77
ADP is provided by the \_\_\_\_\_\_\_\_\_\_\_.
constant breakdown of ATP.
78
why ae enzymes needed by living things?
because most chemical reactions are too slow to be compatible with life.
79
you need 2 things to convert a molecule into another
1. activation energy
2. enzymes
80
Enzymes are \_\_\_\_\_\_\_\_\_\_\_.
biological catalysts made by living cells to help lower the activation energy of a biochemical reaction
81
the same enzyme can continue facilitating reactions as long as\_\_\_\_\_\_\_\_.
substrate is available
82
some enzymes cannot work without \_\_\_\_\_\_\_\_.
cofactors
83
Lock and key model
* the shape of the enzyme is specific to its substrate
* Enzymes have a very specific 3 dementional shape
* when you disrupt the 3d shape of an enzyme, you change the shape of the activation site and it can no longer bind with its substrate.
* Denaturation is loss of the enzyme's 3d structure
84
When there is low [substrate] enzymes work \_\_\_\_\_\_\_.
slower because substrate molecules are spread out.
85
Enzymes convert _________ to \_\_\_\_\_\_\_\_\_\_.
* reactions
* products
86
optimum pH/ Temperature
the temp/ pH at which enzymes best function
87
when is an enzyme considered denatured?
when it can no longer work
88
Why do amalyse enzymes stop working when they reach the stomach?
because the pH of the enviornment is too low and causes denaturation.
89
do all enzymes work at the same pH or temperature?
no, different enzymes have different optimal pH and temperatures
90
what are the types of inhibitors
1. competitive inhibitors
2. non-competitive (allosteric) inhibitors
91
competative inhibitors
competative inhibitors compete with a real substrate for the active site of an enzyme
92
non-competitive/ allosteric inhibitors
binds to enzyme in another spot, which causes a change in the shape of the active site of an enzyme. these types of inhibitors disable enzymes by changing their configuration and distorting its active site.
93
what is an example of a competative inhibitor?
* sulfa drugs (sulfanilamide)
* penicillin
94
sulfanilamide competes with \_\_\_\_\_\_\_\_\_\_
* PABA
* “Sulfanilamide is a competitive inhibitor of bacterial enzyme dihydropteroate synthetase. This enzyme normally uses para-aminobenzoic acid (PABA) for synthesizing the necessary folic acid. The inhibited reaction is normally necessary in these organisms for the synthesis of folic acid. Without it, bacteria cannot replicate.
95
Feedback inhibition
* Also known as end-product inhibition
* Controls amount of substance produced by a cell
* Mechanism is allosteric inhibition
* Feeds back to stop pathway early on to stop the wasting of nutrients.
96
where is the energy for chemical reactions stored?
ATP
97
98
What is the structure of enzymes?
globular proteins with a 3 dementional shape
99
What happens when an enzyme and substrate combine?
the substrate transforms and the enzyme does not change
100
What can be a cofactor for an enzyme?
* iron
* copper
* magnesium
* manganese
* zinc
* calcium
* cobalt
organic molecules/coenzymes:
* NAD+
* NADP+
* FMN
* FAD
* Coenzyme A
101
what happens when an enzyme is at a low temperature?
the reaction rate decreases
102
Do Enzymatic activities increase as the amount of substrate increases?
yes, up until all enzymes are saturated
103
a non competetive inhibitor caan bind with
the apoenzyme or its cofactor
104
Feedback inhabition
occurs when the end-product of a metabolic pathway inhibits an enzyme's activity near the start of a pathway.
105
Ribozymes
Enzymatic RNA molecules involved in protein synthesis
106
What happens during substrate level phosporylation?
a high energy phosphate from an intermediate (occurring in the middle of a process or series) in catabolism is added to ATP.
107
each time a substance is oxidized another is \_\_\_\_\_\_\_
simultaniously reduced
108
NAD+ is the oxidized form of
NADH and NADH is the reduced form of NAD+
109
Is glucose oxidized or reduced?
glucose is a reduced molecule; energy is released during a cell's oxidation of glucose.
110
summary of how ATP is made
Energy released during certain metabolic reactions can be trapped to form ATP from ADP and an inorganic phosphate. addition of an inorganic phosphate is called **phosphorylation.**
111
what happens during oxidative phosphorylation?
energy is released as electrons are passed to a series of electron acceptors (an electron transport chain) and finally to O2 or another inorganic compound.
112
what happens during photophosphorylation?
energy from sunlight is trapped by chlorophyll and electrons are passed through a series of electron acceptors. The electron transfer releases energy used for the synthesis of ATP.
113
Metabolic pathway
a series of enzymatically catalyzed chemical reactions called metabolic pathways store energy in and release energy from organic molecules
114
where does most of a cell's energy come from?
most of a cell's energy is produced from the oxidation of carbohydrates
115
what are the 2 major types of carbohydrate metabolism?
1. Respiration
2. Fermentation
116
During cellular respiration \_\_\_\_\_\_\_\_\_\_\_.
sugar is completely broken down
117
During fermentation \_\_\_\_\_\_\_\_\_\_.
sugar is partially broken down
118
what is the most common pathway for oxidation of glucose
* glycolysis
* Pyruvic acid is the end product
119
how many ATP and NADH are made from 1 glucose molecule?
* 1 glucose molecule
120
NADH
* Nicotinamide adenine dinucleotide (NAD) is a coenzyme found in all living cells. The compound is a dinucleotide, because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adeninebase and the other nicotinamide. Nicotinamide adenine dinucleotide exists in two forms, an oxidized and reducedform abbreviated as NAD+ and NADH respectively.
* In metabolism, nicotinamide adenine dinucleotide is involved in redox reactions, carrying electrons from one reaction to another
121
FADH2
In biochemistry, flavin adenine dinucleotide (FAD) is a redox cofactor, more specifically a prosthetic group, involved in several important reactions in metabolism. FAD can exist in three (or four: flavin-N(5)-oxide) different redox states, which are the quinone, semiquinone, and hydroquinone. FAD is converted between these states by accepting or donating electrons.
FAD, in its fully oxidized form, or quinone form, accepts two electrons and two protons to become FADH2(hydroquinone form). The semiquinone (FADH·) can be formed by either reduction of FAD or oxidation of FADH2 by accepting or donating one electron and one proton, respectively.
122
Pentose phosphate pathway
* used to oxidize 5-carbon sugars; one ATP and 12 NADPH (from NADP+) molecules are produced from 1 glucose molecule.
* Also known as the hexose monophosphate shunt.
* operate simultaneously with glycolysis
* produces important intermediate pentoses used in nucleic acid synthesis, certain amino acids, and glucose from carbon dioxide in photosynthesis.
123
The Entner-Doudorof pathway
yeilds 1 ATP and 2 NADPH molecules from oxidation of 1 glucose molecules
124
Many bacteria have additional
pathways in addition to glycolysis for the oxidation of glucose. The most common alternitive is the pentose phosphate pathway or the entner-doudoroff pathway
125
What happens during respiration?
during respiration organic mole cules are oxidized (lose electrons) Energy is generated fom oxidation (the loss of electrons) of the electron transport chain.
126
what functions as the final electron acceptor in aerobic respiration?
O2
127
what are the final electon acceptrs in anaerobic respiration?
* NO3- (nitrate)
* SO42- (sulfate)
* CO32- (Carbonate)
128
Decarboxylation
**Decarboxylation is _a chemical reaction_ that removes a carboxyl group and releases carbon dioxide** (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain.
129
Decarboxylation of pyruvic acid produces
* 1 CO2 molecule
* one acetyl group
130
what happens to 2 carbon acetyl groups in the krebs cycle?
* they get oxidized in the krebs cycle. Electrons are picked up by NAD+ and FAD for the electron transport chain.
131
What must happen to pyruvic acid so it can enter the krebs cycle?
* it mus be decarboxylated (lose one molecule of CO2) to become a 2 carbon compound
* The 2 carbon compound is called an acetyl group and it attaches to Coenzyme A through a high energy bond to form Acetyl Coenzyme A
* during this reaction pyruvic acid is oxidized and NAD+ is reduced to NADH.
132
oxidation of one glucose molecules produces \_\_\_\_\_\_\_\_\_.
2 pyruvic acids
133
For every 1 glucose that under goes glycolysis
* 2 CO2 molecules are formed
* 2 pyruvic acids are formed
* 2 molecules of NADH are created
134
what happens to Acetyl coA as it enters the krebs cycle?
CoA detaches from the acetyl group and and the acetyl group combines with oxaloacetic acid to form citric acid. This synthesis reaction requires energy which is provided by the high energy bond between acetyl group and CoA
135
in the krebs cycle each reaction is catalyzed by
a specific enzyme
136
how many carbo atoms does Pyruvic acid have?
* 3
* because it was split from a 6 carbon sugar
137
Decarboxylation produces
6 molecules of CO2
138
From 1 molecule of glucose oxidation produces
* 6 molecules of NADH
* 2 molecules of FADH2
* and 2 molecules of ATP
139
What do NADH and FADH2 do with the electrons they pick up?
they both carry electrons to the electron transport chain by NADH
140
what are the carriers in the electron transport chain?
* flavoproteins
* cytochromes
* ubiquinones
141
flavoprotein
any of a class of conjugated proteins that contain flavins and are involved in oxidation reactions in cells.
142
conjugated protein
A conjugated protein is a protein that functions in interaction with other (non-polypeptide) chemical groups attached by covalent bonding or weak interactions. Many proteins contain only amino acids and no other chemical groups, and they are called simple proteins.
143
cytochromes
Cytochromes are iron containing hemeproteins central to which are heme groups that are primarily responsible for the generation of ATP via electron transport.
144
ubiquinones
* Coenzyme Q10, also known as ubiquinone, ubidecarenone, coenzyme Q, and abbreviated at times to CoQ10CoQ, or Q10 is a coenzyme that is ubiquitous (everywhere) in the bodies of most animals.
* This oil-soluble, vitamin-like substance is present in most eukaryotic cells, primarily in the mitochondria. It is a component of the electron transport chain and participates in aerobic cellular respiration, which generates energy in the form of ATP.
145
Proton Motive Force
In most cases the proton motive force is generated by an electron transport chain which acts as a proton pump, using the energy of electrons from an electron carrier (Gibbs free energy of redox reactions) to pump protons (hydrogen ions) out across the membrane, separating the charge across the membrane.
146
oxidative phosphorylation
Oxidative phosphorylation (or OXPHOS in short) is the metabolic pathway in which the mitochondria in cells use their structure, enzymes, and energy released by theoxidation of nutrients to reform ATP.
147
substrate phosphorylation
Substrate-level phosphorylation is a type of metabolic reaction that results in the formation of adenosine triphosphate(ATP) or guanosine triphosphate (GTP) by the direct transfer and donation of a phosphoryl (PO3) group to adenosine diphosphate (ADP) or guanosine diphosphate (GDP) from a phosphorylated reactive intermediate. Note that the phosphate group does not have to come directly from the substrate. By convention, the phosphoryl group that is transferred is referred to as a phosphate group.
148
Chemiosmosis
Chemiosmosis is the movement of ions across a selectively permeable membrane, down their electrochemical gradient. More specifically, it relates to the generation of ATP by the movement of hydrogen ions across a membrane during cellular respiration or photosynthesis.
149
protons being pumped across the membrane generate a \_\_\_\_\_\_\_\_\_\_\_\_\_.
proton motive force as electrons move through a series of of acceptors or carriers
150
How does ATP sythase ATP from ADP and inorganic phosphate?
Energy produced by the movement of protons back across the membrane
151
where are electron carriers located in eukaryotes and in prokaryotes?
* In eukaryotes the electron transport chain is located in the inner mitochondrial membrane
* In prokaryotes electron carriers are located in the plasma membrane.
152
how much ATP is produced in a Eukaryote's mitochondrion from the complete oxidation of glucose?
36 ATP
153
why is the amount of ATP formed in the krebs cycle in anaerobic conditions less than in areobic conditions?
* the total ATP yeild in anaerobic respiration is less than in areobic respiration because only part of the Krebs cycle operates under anaerobic conditions.
154
Fermentation
fermentation releases energy from sugars or other organic molecules by oxidation
155
what is not required for fermentation?
O2
156
during fermentation how many ATP are created by substrate level phosphorylation?
2 ATP
157
electrons removed from the substrate reduce
NAD+
158
in fermentation the final electron acceptor is
an organic molecule
159
In lactic acid fermentation
pyruvate is is reduced by NADH to lactic acid
160
in alcohol fermentation
acetaldehyde is reduced by NADH to produce ethanol
161
Heterolactic fermenters
can use the pentose phosphate pathway to produce lactic acid and ethanol
162
Lipases
hydrolyze lipids into glycerol and fatty acids
163
Fatty acids and other hydrocarbons are catabolized by \_\_\_\_\_\_\_\_\_\_\_\_\_.
beta-oxidation
164
during lipid and protein catabolism catabolic products can
be further broken down in glycolysis and the krebs cycle
165
what must happen to amino acids before they can become catabolized?
they must be converted to various substances that enter the krebs cycle.
166
what reactions convert amino acids so they can be catabolized?
* Transamination
* Decarboxylation
* Desulfurization
167
Transamination
Most amino acids are deaminated byTransamination (or transfer of amino group), a chemical reaction that transfer their amino group to an ketoacid forming new amino acids.
168
desulfurization
a reaction that removes sulfur
169
What is a way that bacteria and yest can be identified?
by detecting the action of their enzymes
170
Fermentation test
used to determine whether an organism can ferment a carbohydrate to produce acid and gas.
171
Photosynthesis
the conversion of light energy from the sun into chemical energy ; the chemical energy is used for carbon fixation.
172
Green plants, algae and cyanobacteria use
Chlorophyll *a*
173
How does chlorophyll work?
electrons from chlorophyll pass through an electron transport chain from which ATP is formed from chemiosmosis
174
Photosystems
are made up of chlorophyll and other pigments packed into thylakoid membranes
175
during cyclic phosphorylation electrons \_\_\_\_\_\_\_
return to the chlorophyll
176
what happens during non-cyclic phosphorylation?
the electrons are used to reduce NADP+ The electrons from H2O or H2S replace those lost from chlorophyll
177
what happens when green plants, algae and cyanobacteria oxidize H2O?
O2 is produced
178
What happens when sulfur bacteria oxidize hydrogen sulfide (H2S)
elemental sulfur granules are produced (S0)
179
CO2 is used to synthesize sugars in the \_\_\_\_\_\_\_\_\_\_\_\_\_.
Calvin-Benson cycle
180
phototrophs
use sunlight to convert chemical energy in oxidation reactions carried on by phototrophs
181
Chemotrophs
can use the chemical energy that phototrophs make
182
What does a cell need to produce energy
1. electron donor (organic or inorganic)
2. a system of electron carries
3. a final electron acceptor (organic or inorganic)
183
Chemoautotrophs
use inorganic compounds as their energy source and carbon dioxide as their carbon source
184
Chemoheterotrophs
use complex organic molecules as their carbon and energy source
185
what is glycogen formed from?
ADPG
186
UDPNAc
the starting material for the synthesis of peptidoglycan
187
what are lipids sythesized from?
fatty acids and glycerol
188
where is glycerol derived from?
dihydroxyacetone phosphate and fatty acids are built from acetyl CoA
189
what substance(s) are required for protein biosynthesis?
amino acids
190
all amino acids can be ___________ either directly or indirecctly from intermediates of _________________ particullarly from the \_\_\_\_\_\_\_\_\_\_\_.
* synthesized
* carbohydrate metabolism
* krebs cycle
191
where do the sugars composing nucleotides come from?
1. The pentose phosphate pathway
2. Entner-Doudoroff pathway
192
what forms the back bones of purines and pyrimidines?
carbon and nitrogen atoms from certain amino acids
193
what are anabolic and catabolic interactions integrated through?
a group of common intermediates
194
amphibolic
integrated metabolic pathways
195
196
In biological systems, the electrons are often associated with \_\_\_\_\_\_\_\_\_\_.
hydrogen atoms
197
Biological oxidations are often \_\_\_\_\_\_\_\_\_\_\_\_.
dehydrogenations
198
cellular respiration uses __________ to make ATP.
Redox
199
Substrate phoporylation
transfer of a high-energy PO4– to ADP
200
Oxidative phosphorylation
transfer of electrons from one compound to another is used to generate ATP by chemiosmosis.
201
Energy in a glucose molecule is stored in the ____________ between carbon atoms. EVERY TIME a bond is broken between two carbons, the shared electrons within that bond must be \_\_\_\_\_\_\_\_\_\_. They cannot be left to float aimlessly around the cell. Electron carrier molecules, such as _______________ accept \_\_\_\_\_\_\_\_\_and \_\_\_\_\_\_\_\_\_\_\_\_\_(dehydrogenation) and are reduced to _________ and ________ respectively.
* Covalent bonds
* captured
* NAD+ and FAD
* electrons
* protons
* NADH
* FADH2
202
what are alternate glucose catabolism pathways for?
Alternative pathways are for breakdown of 5-carbon sugars or glucose to produce NADPH and may or may not occur when glycolysis is occurring.
* pentose phosphate pathway
* Entner-duodoroff pathway
203
Transition step
•Transition step generates
acetyl-CoA from pyruvate (decarboxylation)
204
Acetyl group of acetyl-CoA enters TCA cycle and ....
–Generates ATP and reducing power
–Generates precursor metabolites
205
metabolite
a substance formed in or necessary for metabolism.
206
TCA cycle
Citric acid is a so-called tricarboxylic acid, containing three carboxyl groups (COOH). Hence the Krebs cycle is sometimes referred to as the tricarboxylic acid (TCA) cycle.
207
How the electron transport chain works
The process by which ATP is produced in the inner membrane of a mitochondrion: The electron transport system transfers protons from the inner compartment to the outer as electrons are passed from one protein to another. As the protons flow back to the inner compartment through ATP synthase, the energy of their movement is used to add phosphate to ADP, forming ATP.
208
another name for Proton motive force (PMF)
proton gradient
209
how does PMf generate energy during chemiosmosis?
•In chemiosmosis, pmf generates energy via oxidative phosphorylation
210
if the final electron acceptor is nitrate (NO3-) the products will be..
* Nitrogen dioxide (NO2-)
* Nitrogen gas (N2) and H2O
211
If the final electron acceptor is SO4- (sulfate) the products will be
* Hydrogen sulfide (H2S) and H2O
212
if the final electron acceptor is carbonate (CO32-) the products will be...
* methane (CH4) and H2O
213
industrial definition of fermentation
* Spoilage of food by microorganisms (general use)
* Any process that produces alcoholic beverages or acidic dairy products (general use)
* Any large-scale microbial process occurring with or without air (common definition used in industry)
214
scientific definition of fermentation
* Uses an organic molecule as the final electron acceptor
* Does not use the Krebs cycle or ETC
* Energy yield low
* Diversity of end products:
Ethanol, lactic acid, citric acid, methane, acetone, acetic acid, propionic acid + CO2
215
how mant ATPs are produced in eukaryotes using oxygen as the final electron acceptor
38 ATP
216
Proteins, carbohydrates, and lipids are all sources of \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
* electrons for cellular respiration
* They are broken down into various small molecule components that enter cellular respiration pathways at various points
217
Saprophytes
Saprophytes prefer dead/decaying material
218
parasites
parasites prefer to colonize a living host
219
Cellulase
digestion of cellulose (only bacteria and fungi have this enzyme)
220
The ability to use amino acids as a source of energy is highly specific to different bacteria; different species produce different enzymes that can perform these metabolic reactions. What does the presence of certain enzymes mean?
* the identity of a particular species, can be confirmed by biochemical testing.
* The test can detect enzymes
221
Phototrophs
get energy from light
222
Chemotrophs
get energy from inorganic chemicals
223
Heterotrophs
get carbon from organic molecules
224
autotrophs
get carbon from CO2
225
Chemoheterotrophs
•use same organic compound as energy source and carbon source. Most medically important bacteria.
226
in which kingdom are all the nutritional modes found?
bacteria; they have a diversity of metabolic pathways
227
