Studied by 1 personWhen we shiver on a cold day, the heat produced by muscle tissue is a demonstration of
the second law of thermodynamics.
Which is a form of energy that is generally unavailable to do any work?
Heat
Which one of the following choices includes three descriptions that are consistent with each other (that is, that describe the same type of chemical reaction)?
Anabolic, dehydration, endergonic
In a chemical reaction where an electron is exchanged from one reactant to another, the structure that loses an electron is
oxidized.
The term "activation energy" refers to the amount of energy
required to initiate any chemical reaction.
ATP formation
is endergonic and requires the presence of fuel molecules such as glucose.
Noncompetitive inhibition of an enzyme occurs when the inhibitor binds to the
allosteric site, and its effectiveness is not influenced by substrate concentration.
Pancreatic amylase _________ the cells that make it, so the enzyme can serve its function (digestion of starch) in the lumen of the small intestine.
is secreted from
Phosphorylation is carried out by a
kinase, and it may activate some enzymes and inhibit others.
At temperatures above 40°C (104°F) in the human body,
enzymes denature and reaction rates decrease.
Enzyme regulation by negative feedback involves
allosteric inhibition of an enzyme by a product of its metabolic pathway.
An enzyme that is described as a protein kinase is a
transferase that transfers a phosphate group to a protein substrate.
In the final step of enzymatic catalysis,
the products are released and the enzyme is free to bind other substrates.
Which answer lists the steps of enzyme action in correct order?
Formation of enzyme-substrate complex, induced fit, formation or breakage of chemical bonds, release of product
The citric acid cycle involves
several enzymes within the matrix of the mitochondrion.
The electron transport chain
requires oxygen, and involves proteins in the cristae of mitochondria.
During the early steps of glycolysis, glucose is converted to glucose 6-P, and then glucose 6-P is converted directly to
fructose 6-P.
Which stage of cellular respiration is catalyzed by pyruvate dehydrogenase?
Intermediate stage
The coenzymes that will provide the electrons needed for the electron transport system are
NADH and FADH2.
The intermediate stage of cellular respiration
produces carbon dioxide and occurs in the mitochondria.
According to the second law of thermodynamics, when energy is transformed from one kind to another
some of it is converted to heat.
When our inner ears convert sound energy into neural impulses or our retinas convert light into neural impulses,
the conversion is consistent with both laws of thermodynamics.
The breakdown of H2CO3 into CO2 and H2O is catalyzed by an enzyme called carbonic anhydrase. Which of the following is a reactant in this reaction?
H2CO3
When the body's digestive system breaks down starch, a complex carbohydrate, into simpler carbohydrates, the reaction is
catabolic and exergonic.
The reaction in which water and carbon dioxide combine to form carbonic acid is
reversible, and can proceed in either direction depending on the concentrations of the molecules.
Which enzyme system allows for regulation at a single site and also diminishes the chance that a needed substrate will diffuse away from a catalyst?
Multienzyme complex
Which enzyme class splits a chemical bond in the absence of water?
Lyase
Lactose intolerance is caused by the lack of the enzyme lactase. This enzyme _________ the cells that make it.
is embedded within the membranes of
To prevent depletion of a substrate, the product of a metabolic pathway will
turn off an enzyme early in the pathway.
Structurally, enzymes are generally
globular proteins
In performing its enzymatic function, carbonic anhydrase
requires the inorganic coenzyme zinc.
Which enzyme class transfers electrons from one substance to another?
Oxidoreductase
One turn of the citric acid cycle results in the formation of
1 ATP, 3 NADH, and 1 FADH2
The more common way that ATP is produced in cells is
the indirect pathway known as oxidative phosphorylation.
The total number of ATP generated by the breakdown of glucose is 38, but the net number of ATP generated is
30
Fatty acids enter the cell respiration pathway at
the citric acid cycle, once they have been converted to acetyl CoA.
Which of the following choices lists the order of stages of cellular respiration in proper order?
Glycolysis, intermediate stage, citric acid cycle, and the electron transport system
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