Microbiology Ch. 6 Fueling Cell Growth
Which of the following correctly describes some of the forms of energy represented in this photograph?
Electricity generated by the hydroelectric dam as it captures the energy from moving water. Kinetic energy of the photons that make up the sunlight. Potential energy of the water behind the dam.
Metabolic pathways can be linear, ___, or ___.
brached; cyclical
All of the following accurately describe enzymes EXCEPT:
enzymes provide energy to help reactions proceed more rapidly.
The energy released by an ___ reaction can be used by a cell to drive an ___ reactions.
exergonic; endergonic
The graph shows the relative energy as a reaction proceeds. in terms of energy, the reaction catalyzed with an enzyme (red line) is ___, and the reaction that proceeds without that proceeds without an enzyme (blue line) is ___.
exergonic; exergonic
An atom that has a lower affinity (attraction) for elections than another is described as ___ than the other.
less electronegative
Identify each of the following as either a cofactor or coenzyme: magnesium: ___; NADP+:___; zinc: ___.
cofactor; coenzyme; cofactor.
In aerobic respiration, ___ serves as the terminal electron acceptor.
O2
The main energy currency of cells is ___.
ATP
Which statement correctly describes how catabolism and anabolism are intimately linked?
ATP made during catabolism is used in anabolism
All of the following processes commonly rely on microbial metabolism to produce items for human use EXCEPT:
Conversion of crude oil to gasoline at a coastal refinery.
Which of the following are true statements regarding energy?
Energy can exist as kinetic energy. Energy cannot be created. Energy is the capacity to do work. Energy can exist as potential energy.
Recall that E. coli can grow in glucose-salts medium, which contains only glucose and a few inorganic salts. This means the glucose is serving what two purposes in the cell?
Energy source Starting point from which all cell components are made
Until the optimal temperature is reached, each 10 degree C rise in temperature has what approximate effect on the speed of enzymatic reactions?
it doubles the rate of the reaction
In photosynthesis, the set of reactions that capture radiant energy and convert it into chemical energy in the form of ATP is called the ___ -___ reactions.
light dependent
The sum total of all chemical reactions in a cell is called ___.
metabolism
Oxidative phosphorylation is the mechanism by which cellular ___ uses the reducing power generated in glycolysis, the transition step, and the TCA cycle to sythesize ATP.
respiration
All of the following represents two fundamental tasks cells need to accomplish in order to grow EXCEPT:
sexual reproduction
Free energy is best defined as:
the energy available to do work
Metabolism is best defined as:
the sum total of all chemicals reactions in a cell
Certain intermediates of catabolic pathways, called precursor metabolites, are important because:
they serve as carbon skeletons from which subunits of macromolecules can be made.
Rank the following energy-generating processes from greatest energy yield to least energy yield.
1. Aerobic respiration 2. Anaerobic respiration 3. Fermentation
Which of the following accurately describe fermentation?
Glucose is broken down via glycolysis. Fermentation does not involve the tricarboxylic acid(TCA) cycle. NAD+ is regenerated from NADH by the transfer of electrons to pyruvate or derivative.
The central metabolic pathway that splits glucose and gradually oxidizes it to form two molecules of pyruvate is ___.
Glycolysis
What occurs during the transition step of central metabolism?
The 2-carbon acetyl group is joined to coenzyme A to form acetyl-CoA. Electrons are transferred to NAD+, reducing it to NADH + H+ CO2 is removed from pyruvate.
Which of the following correctly describe respiration?
The electron transport chain uses the electrons to generate a proton motive force that can be used to generate ATP. Electrons extracted from glucose are transferred to the electron transport chain
Which of the following best describes the conversion of energy from one form to another illustrated in the picture?
The potential energy of water stored behind the dam is converted to kinetic energy of moving water, which is converted to electrical current.
Anabolism
The set of chemical reactions that synthesize and assemble the sub-units of macromolecules.
Catabolism
The set of chemical that degrade compounds, releasing their energy.
Which of the following correctly describes the transition step and the tricarboxylic acid (TCA) cycle?
Together they generate the most reducing power of all the central metabolic pathways. They produce three metabolities and ATP The transition step converts the pyruvate from glycolysis into acetyl-CoA The TCA cycle oxidizes a 2-carbon acetyle group to release two molecules of CO2.
Which of the three central metabolic pathways generate a modest amount of ATP via substrate level phosphorylation?
Tricarboxylic acid (TCA) cycle Glycolysis
True or False: the change in free energy for a given reaction is the same regardless of the number of steps involved.
True
Considering only the carbon, the TCA cycle incorporates an ___ group from the transition step and releases two molecules of ___ and two molecules of ___.
acetyl, ATP, CO2
The critical site of an enzyme to which a substrate binds by weak forces is called the ___ ___.
active site
The three key metabolic pathways that gradually oxidize ___ to CO2 are collectively referred to as the central metabolic pathways.
glucose