Microbio Chapter 11
A single turn of the Krebs cycle will yield ________.
1 ATP, 3 NADH, and 1 FADH2
Following the formation of acetyl-CoA, the initial reaction of the Krebs cycle involves the addition of a ____________.
2-carbon molecule to a 4-carbon molecule
The net products from oxidation of glucose to pyruvate in Embden-Meyerhof pathway are ________.
2NADH and 2ATP
Assuming a P/O ratio of 2.5 for the oxidation of NADH and 1.5 for FADH2, the theoretic maximum yield of ATP during aerobic respiration is _____.
32
The pentose phosphate pathway is connected to the Embden-meyerhof pathway by the oxidation of glucose 6-phosphate to _______.
6-phosphogluconate
Anaerobic respiration does not produce as much _______ as aerobic respiration because alternate electron acceptors such as nitrate have less positive reduction potential than oxygen.
ATP
One of the three products made by organisms through the fueling reactions is _________, the primary molecule used to conserve the energy supplied by an energy source.
ATP
What term describes organisms that obtain their energy by oxidizing organic compounds made by autotrophic organisms?
Chemoorganoheterotrophs
In the TCA cycle, ATP or GTP is generated by substrate-level phosphorylation when _________.
CoA is cleaved from the succinyl-CoA
______________ refers to the removal of an amino group from an amino acid. One mechanism for this removal is ___________, in which the amino group is transferred to an acceptor molecule.
Deamination; transamination
Where do NADH and FADH2 go after being produced in the tricarboxylic acid cycle
ETC
What is the major glycolytic pathway used by plants and animals?
Embden-Meyerhof
The TCA cycle generates two CO2 molecules, three NADH molecules, one _________, and either one ATP or GTP for each acetyl-CoA molecule oxideized.
FADH2
Which molecule is produced in the largest numbers by the TCA cycle?
NADH
The pentose phosphate pathway is a major source of reducing power for cells, yielding two _________ molecules for each molecule of glucose that is metabolized to pyruvate.
NADPH
The pyruvate dehydrogenase complex oxidizes and cleaves pyruvate to form one CO2 and ___________.
acetyl-CoA
Before entering the Krebs cycle, pyruvate is converted to ________.
acetyl-coA
In the TCA cycle, two carbons in the form of ________ are added to oxaloacetate at the start of the cycle.
acetyle-CoA
The pentose phosphate pathway is used by _________.
all organisms
Pathways that function both catabolically and anabolically are often called ________.
amphibolic
Protons received from NADH _________.
are pumped across the membrane
The use of nitrate and other electron acceptors by chemoorganotrophs links the carbon cycle to other _________ cycles such as the nitrogen cycle and the sulfur cycle.
biogeochemical
In the TCA cycle, two carbons are removed from the citric acid in the form of _______, thereby regenerating oxaloacetate to complete the cycle.
carbon dioxide
The six carbons of the glucose molecule that enter the cell respiration pathway end up in/as ________ by the end of the process.
carbon dioxide
The hypothesis that PMF drives ATP synthesis is called the ___________ hypothesis.
chemiosmotic
Certain bacteria and archaea are _____, donating electrons to their ETCs by oxidizing inorganic molecules rather than organic nutrients.
chemolithotrophs
The low yield of ATP means that ___________ must oxidize a large quantity of inorganic material to grow and reproduce.
chemolithotrophs
Which nutritional classification would you predict to fit most of the well-known members of the human microbiome?
chemoorganoheterotrophs
A microorganism that obtains its energy from the oxidation of chemical compounds (either organic or inorganic) is referred to as a ________.
chemotroph
In eukaryotes, glycolysis takes place in the _______.
cytoplasm
Where does the Krebs cycle take place in bacteria?
cytoplasm
The first step in amino acid catabolism is ____________, the removal of the amino group from an amino acid.
deamination
When dissimilatory nitrate reduction leads to the production of gaseous compounds such as N2 that are released into the atmosphere, the process is also called ________.
denitrification
What does carbon dioxide go when it is released during reactions of the Krebs cycle?
diffuses out of the cell
Triglycerides can by hydrolyzed to glycerol and fatty acids. The glycerol is then phosphorylated and oxidized to _____________, an intermediate of the Embden-Meyerhof pathway.
dihydroxyacetone phosphate
Anaerobic reduction of nitrate is called ________ nitrate reduction because it makes the nitrogen unavailable for use in constructing N-containing molecules such as amino acids and nucleotides
dissimilatory
When nitrate is used a final electron acceptor by bacteria growing in anoxic soils, the nitrogen is no longer available for the construction of precursor metabolites. This is referred to as ______.
dissimilatory nitrate reduction
T/F: An organism can fit into only one nutritional pattern and cannot change if the environment conditions change.
false
T/F: Many chemolithotrophs are able to produce more ATP from oxidation of their inorganic energy source than chemoheterotrophs produce from the aerobic oxidation of glucose.
false
T/F: Oxygen is always required for the regeneration of NAD from NADH.
false
T/F: Some aerobic bacteria lack the Enter-Doudoroff and Embden-Meyerhof pathways and instead use the pentose phosphate pathway for glycolysis.
false
T/F: The electron transport system of prokaryotes and eukaryotes are the same.
false
T/F: The formation of ATP as a result of the activity of the electron transport system is termed substrate-level phosphorylation.
false
T/F: The tricarboxylic acid cycle is part of fermentation, as well as cellular respiration.
false
T/F: Under aerobic conditions, the end product of glycolysis is further reduced to yield more ATP.
false
T/F: metabolic pathways can be either catabolic or anabolic but not both.
false
In addition to its role in ATP synthesis, in bacteria the PMF provides energy to drive ________.
flagellar rotation and nutrient uptake
What monosaccharide requires UTP for phosphorylation before degradation can occur?
galactose
The catabolic pathways of greatest importance to chemoorganotrophs are the _________ pathways and the tricarboxylic acid (TCA) cycle.
glycolytic
Because mitochondrial ETCs consist of four complexes arranged in order, the strength of the proton motive force is _______ than that produced by bacteria and archaeal ETCs.
greater
Organisms that for lactate, ethanol, and CO2 as end products of glucose metabolism are called ________ fermentors.
heterolactic
Disaccharides and polysaccharides can be processed as nutrients after first being cleaved to monosaccharides by either __________ or __________.
hydrolysis; phosphorolysis
Disaccharides can be directly __________ to their constituent sugars or may be split by a phosphate attack on the bond joining the two sugars, a process called _________.
hydrolyzed; phosphorolysis
The movement of protons through ATP synthase in eukaryotes occurs from the ________.
intermembrane space to the matrix
The most common fermentation is ______ acid fermentation.
lactic
In aerobic conditions, it takes _________ sugar to produce the same amount of ATP when compared to anaerobic conditions.
less
Glucose, fructose, and _______ are phosphorylated using ATP before entering the Embden-Meyerhof pathway.
mannose
The TCA cycle enzymes are located in the matrix of each _______ in eukaryotic cells.
mitochondria
Nitrifying bacteria are organisms in the soil and water that carry out the oxidation of ammonia to nitrate. This process is known as _______.
nitrification
Many purple _________ bacteria act as photoorgaonheterotrophs in the absence of oxygen but oxidize organic molecules and function chemoorganotrophically at normal oxygen levels.
nonsulfur
Mitochondrial electron transport takes place __________.
on the inner mitochondrial membrane
The net gain of ATP per molecule of glucose metabolized to pyruvate using Enter-Doudoroff pathway is ____?
one
The net yield of the TCA cycle for each acetyle-CoA molecule oxidized includes ________.
one ATP or GTP molecule
ATP synthase in fermenting microbes pumps protons ___________ the cell, fueling this transport by the energy released when ATP is hydrolyzed to ADP and P.
out of
Energy released by the oxidation of ammonia, nitrite, and sulfur-containing compounds by chemolithotrophs is used to make ATP by ________ phosphorylation.
oxidative
In aerobic respiration, electrons are donated to an ETC that uses ___ as the terminal electron acceptor.
oxygen
Many disaccharides can be catabolized to monosaccharides by a phosphate attack on the bond joining the two sugars, a process called __________.
phosphorolysis
Some bacteria and fungi use proteins as their source of carbon and energy. They secrete enzymes called ______ that hydrolyze proteins to amino acids, which are transported into the cell and catabolized.
proteases
Some microbes can hydrolyze proteins to amino acids through the use of enzymes called ___.
proteases
According to the chemiosmotic hypothesis, mitochondrial ETCs are organized so that ______ move across the inner membrane from the mitochondrial matrix to the intermembrane space as _______ are transported down the chain.
protons; electrons
After the glycolytic pathway produces ____, the partially oxidized carbon is fed into the TCA cycle and oxidized completely to CO2 with the production of some GTP or ATP, NADH, and FADH2.
pyruvate
The TCA cycle is linked to the Embden-Meyerhof and pentose phosphate pathways through the ______ molecule.
pyruvate
Less energy is available to make ATP in anaerobic respiration because energy yield is directly related to the magnitude of the ______ potential difference.
reduction
The process of decarboxylation involves _____.
removing carbon
In order for chemolithotrophs to make the NAD(P)H they need, they must use a process called ___________ electron flow.
reverse
How does a fermenter generate proton motive force to drive active transport?
reverse the direction of ATP synthase
The pentose phosphate pathway produces two important precursor metabolites: erythrose 4-phosphate, used to synthesize aromatic amino acids and vitamin B6 (pyridoxal), and _______, a major component of nucleic acids
ribose 5-phophate
Bacterial and archaeal electron transport chains may be _______ than mitochondrial ETCs, resulting in the release of less energy and the transport of fewer protons across the membrane.
shorter
How is ATP produced during fermentation?
substrate-level phosphorylation
The most common terminal electron acceptors used during anaerboic respiration are nitrate, _________, and carbon dioxide.
sulfate
Most of the energy used to make ATP during aerobic respiration is conserved by the activity of ________.
the ETC
In cellular respiration, the pathways of glycolysis are followed by __________.
the TCA cycle, leading to the electron transport chain
For one turn of the Krebs cycle, how many NADH are produced?
three
T/F: An organism may use glycolysis and the pentose phosphate pathway simultaneously.
true
T/F: Bacterial electron transport chains may be comprised of fewer components and have lower phosphate to oxygen (P/O) ratios than mitochondrial transport chains.
true
T/F: During glycolysis, a 6-carbon sugar diphosphate molecule is split into two 3-carbon sugar phosphate molecules.
true
T/F: Glycolysis and the TCA cycle are two of the most important catabolic pathways in chemoorganotrophs.
true
T/F: In addition to being used in the making of ATP, a proton motive force is used directly to power the rotation of bacterial flagella.
true
T/F: Oxidative decarboxylation takes place when pyruvate from the glycolytic pathway is oxidized, producing acetyl-CoA along with CO2 and one NADH.
true
T/F: Prokaryotes may use several different terminal oxidases for the electron transport system.
true
T/F: Pyruvate is converted to carbon dioxide via three separate decarboxylation reactions during the TCA cycle.
true
T/F: The Krebs cycle occurs in the mitochondrion of eukaryotes and the cytoplasm of bacteria and archaea.
true
T/F: The catabolism of glucose begins with one or more of the glycolytic pathways that yield pyruvate.
true
T/F: The energy capture in the phosphorylation of ADP to ATP comes from proton motive force created when energy is released following the oxidation of electron carriers.
true
T/F: When oxygen accepts electrons, water is produced as a byproduct.
true
For each glucose molecule that enters glycolysis, how many times does the Krebs cycle turn?
two
How many net ATP molecules are produced for each glucose molecule that enters glycolysis.
two
