Microbiology Ch 8
--- act as catalysts in virtually all metabolic pathways.
Enzymes
Complex II of of the electron transport chain accepts electrons from the carrier called ---
FADH2
Which best describes the function of enzymes?
Facilitate metabolic pathways
Which of the following identifies best the reason for the Krebs cycle must occur twice per glucose molecule?
Glucose will yield two pyruvates
--- refers to the decomposition of complex compounds during cellular metabolism, usually with the release of energy
Metabolism
During the conversion of pyruvic acid to acetyl CoA, electrons reduce
NAD+
Complex I in the electron transport chain accepts electrons from the carrier called
NADH
The first release of carbon dioxide during glucose metabolism occurs during the formation of ________.
acetyl CoA
What term is used to describe the minimum amount of energy required for a reaction to proceed?
activation energy
In -- respiration, electrons are transferred from fuel molecules to oxygen which acts as the terminal electron acceptor.
aerobic
ATP synthase is principally composed of ______.
amino acids
The specific process of ______ incorporates nutrients into larger, complex structures through biosynthesis.
anabolism
A non-functional enzyme which needs a cofactor is called a(n)
apoenzyme
What term refers to a biological catalyst that lacks an essential cofactor?
apoenzyme
Which of the following is the decomposition of complex compounds during cellular metabolism?
catabolism
If internal cellular enzymes are denatured, it can lead to:
cell death
A --- is an organic molecule or inorganic element that may be required for an enzyme to become functional.
cofactor
A(n) --- is an organic molecule or inorganic element that may be required for an enzyme to become functional.
cofactor
The reduction of nitrite to nitrous oxide or nitrogen gas by some species of bacteria is called ________.
denitrification
The Kreb's cycle has --- steps
eight
All cells need a constant input and expenditure of ________ in a usable form.
energy
True or false: Plants are the principle producers of oxygen on Earth.
false
The addition of carbon dioxide to ribulose-1,5-bisphosphate to begin the Calvin cycle is known as carbon
fixation
--- is the multi-step energy-yielding conversion of glucose to pyruvic acid.
glycolysis
Which of the following metabolic pathways begins with glucose and yields two pyruvates?
glycolysis
Which term is used to describe a stack of thylakoids?
grana
On land, the primary photosynthesizers are _______.
green plants
Which is NOT one of the main photosynthesizers of aquatic ecosystems?
green plants
Which does NOT undergo oxygenic photosynthesis?
green sulfur bacteria
One evolutionary strategy to deal with an "enzymatic-block" to a particularly necessary metabolic product is to
have alternative enzymatic methods to synthesize the product
The production of mixed acids, one being lactic acid, during fermentation is a good definition of --- fermentation
heterolactic
An enzyme with its apoenzyme and cofactors is referred to as a(n) --- or a conjugated enzyme
holoenzyme
Typically -- ATP are netted by fermentation.
2
During acetyl CoA formation --- CO2 and --- NADH are produced per initial glucose that enters glycolysis
2 and 2
What is the maximum yield of ATP from aerobic respiration in prokaryotes?
38
-- is the cellular process of taking monomers of compounds and producing polymers (e.g., amino acids are combined to make proteins).
Anabolism
Slight changes occur in the shape of the enzyme in order to guide the substrate into the active site. This is referred to as a(n)
induced fit
In strict aerobes and some anaerobes, pyruvic acid enters the --- or citric acid cycle
krebs
Fermentation results in the production of ______ ATPs than aerobic and anaerobic respiration.
less
Compounds that are oxidized will
lose electrons
Typically, the presence of enzymes ____ the activation energy for a reaction to proceed.
lowers
The location of the Krebs cycle enzymes in eukaryotes is in the --- matrix, while in prokaryotes the enzymes are found in the ---
mitochondria, cytoplasm
In eukaryotic cellular respiration, the charge gradient that exists between the inner and outer --- membranes during chemiosmosis is called proton motive force
mitochondrial
Which type of fermentation best describes degradation of pyruvic acid that results in the production of some combination of lactic, acetic, succinic, and formic acids?
mixed acid
Which serves as a terminal electron acceptor in fermentation?
organic compounds
What term is used to describe the process of ATP production from the ETS?
oxidative phosphorylation
--- is simply NOT part of the fermentation pathway
oxygen
In the last step of the ETS, the electrons are passed to --- along with hydrogen which results in the formation of ---
oxygen, water
What term is used to describe photosynthesis reaction which produce oxygen as a waste product?
oxygenic
In bacteria, protons are moved from the cytoplasm to the --- space during chemiosmosis
periplasmic
Most enzymes are a functional type of
proteins
As hydrogen ions accumulate between the inner and outer membranes of the mitochondrion, a(n) _____ is generated which powers ATP production.
proton motive force
The charged gradient which is formed in the ETS results in the
proton motive force
Typically, once an enzyme performs a "job", it is
ready to work again
A catalyst composed of RNA is called a(n)
ribozymes
Which of the following represent cofactors?
small organic molecules, coenzymes, metal ions
The --- is the term for a specific molecule on which an enzyme acts.
substrate
Select the ways that cells manage the energy needed for metabolic reactions.
transferring electrons, making and breaking chemical bonds
Changes in environmental conditions can cause the denaturation of cellular enzymes, resulting in blocks to metabolic reactions and ultimately in cell death. true or false
true
The Kreb's cycle must turn --- times for each glucose that entered glycolysis
two
The bonds that form enzyme-substrate complexes are --- and easily reversible
weak
The final step of the ETS in aerobic respiration occurs when electrons are passed to
O2
Which of the following could not be a cofactor?
Organic acids
Which best defines an active site?
Region of an enzyme where the substrate binds
What is the cellular location of photosynthetic pigments in eukaryotes?
Thylakoid membrane