the study of energy transformations is referred to as
thermodynamics
the two pathways to ATP production are
substrate-level phosphorylation and oxidative phosphorylation
intermediate stage
catalyzed by a multienzyme complex, substrate is pyruvate, 2 NADH
glycolysis
substrate is glucose, is anaerobic, 2 ATP and 2 NADH
citric acid cycle
reduces FAD to FADH2, produces 2 ATP, 6 NADH, and 2 FADH2
at equilibrium, a reversible reaction proceeds in _____ direction(s)
both
reversible reaction
CO2 + H2O -><- H2CO3
which of the following determine reaction rate in an enzyme-catalyzed reaction?
the energy required to break existing bonds and the activation energy
true or false: activation energy is only required in endergonic reactions
false
the measure of how quickly a chemical reaction takes place is known as the
reaction rate
enzymes
increase reaction rate, decrease activation energy, and it is a catalyst
_____ is the collective term for all the synthesis reactions in the body
anabolism
a _____ binds to the active site of an enzyme to stop the enzyme from catalyzing a reaction
competitive inhibitor
enzyme action steps
substrate binds to active site, change in enzyme structure leads to induced fit, the change in enzyme structure stresses bonds in the substrate, substrates bonds are broken, new bonds are formed, the product is released from enzyme
which are the products of pyruvate dehydrogenase?
acetyl coa and co2
what type of reaction results when small molecules combine to make a larger one?
synthesis
the smallest enzymes are around _____ amino acids long
60
how many turns of the citric acid cycle are required to break down one molecule of glucose?
2
a biologically active catalyst is known as a(n)
enzyme
which of the following organic molecules may be oxidized to generate ATP?
glucose, amino acids, and fatty acids
which word describes decomposition in the body?
catabolism
which type of reaction involves both synthesis and decomposition?
exchange
an _____ reaction occurs when electrons are transformed from one chemical structure to another
oxidation-reduction
if an electron and a hydrogen ion are removed, the structure is said to have been
oxidized
if a hydrogen ion and an electron is added to a structure during a chemical reaction, the structure is said to have been
reduced
in an _____ reaction, the amount of energy in the products is less than the amount of energy in the reactants
exergonic
most catabolic reactions release energy meaning they are also _____
exergonic
in an _____ reaction, the products have more energy than the reactants
endergonic
most anabolic reactions are also _____, meaning that they require energy
endergonic
if the rate of a reaction leads to a net loss of reactants, then the reaction is called
irreversible
classifying chemical rations
changes in chemical energy, chemical structure, reversibility/irrebersibility
when a molecule or ion gains an electron during a reaction, it is said to have been
reduced
which terms can be used to classify reactions based on the relative amounts of energy in reactants and products?
exergonic and endergonic
oxidoreductase
transfer electrons from one substance to another
transferase
transfers a functional group
hydrolase
splits a chemical bond using water
isomerase
converts one isomer to another
ligase
bonds two molecules together
lyase
splits a chemical bond in the absence of water
which are considered part of the electron transport chain?
electron carriers, H+ pumps, ATP synthase
true or false: glucose is preferentially oxidized during times of fasting or starvation
false
_____ energy is the energy of position or stored energy. _____ energy is the energy og motion
potential/kinetic
the collective term for all of the chemical reactions in a living organism is
metabolism
chemical reactions can be classified by the relative amounts of energy in the reactants and products by using the terms
exergonic and endergonic
which are forms of radiant energy?
ultraviolet light, visible light, radio waves
which are forms of kinetic energy?
mechanical energy, radiant energy, sound energy
true or false: heat is usually available to do work
false
a student proposed that a chemical reaction would create more energy than the original reactants possessed. this would violate the _____ law of thermodynamics
first
the _____ law of thermodynamics states that a quantity of energy can't be completely transferred from one form into another
second
which function(s) primarily as energy storage in the human body?
triglycerides, ATP, glycogen
the propagation of an impulse in a neuron is an example of
electrical energy
true or false: the heart moves blood by imparting electrical energy to the blood
false
the vibrating strings on a violin imparts _____ kinetic energy to the air around it
sound
mechanical and electrical energy are both forms of _____ energy
kinetic
the _____ law of thermodynamics states that energy can neither be created nor destroyed
first
which of the following are locations of enzymes involved in glucose oxidation?
the cytosol and the mitochondria
_____ are present prior to the start of a chemical reaction
reactants
which are involved in a chemical reaction?
formation of chemical bonds and breakdown of chemical bonds
a _____ is a method of writing a summary of the changes that occur in a chemical reaction
chemical equation
a(n) _____ chemical reaction occurs when a large molecule is broken down into smaller structures
decomposition
which are true of chemical energy?
chemical energy is used for synthesis of molecules, chemical energy is used to establish concentration gradients, and chemical energy is a form of potential energy
true or false: proteins can serve as a form of energy storage in describing forms of kinetic energy, _____ energy is the energy of an object in motion, while _____ energy is the energy of vibrations in solids, liquids, or gasses
mechanical/sound
the higher the frequency of radiant waves, the _____ the energy of the wave
higher
which type(s) of radiant energy could penetrate the body and mutate DNA?
gamma rays
the pigment melanin protects the skin from
UV light energy
whenever energy is transferred from one form to another, some of that energy is lost as
heat
glycolysis steps
glucose splits into two molecules of glyceraldehyde-3-phosphate, NADH and ATP are formed, ATP and pyruvate are formed
how many molecules of ATP are formed during glycolysis?
4
phosphofructokinase contains an allosteric regulatory site which binds to
ATP
phosphofructokinase is the target of _____ to regulate glycolysis
negative feedback
if oxygen is not present, then pyruvate is converted to
lactate
the cristae of mitochondria are formed from folds in the
inner membrane
the reaction of the _____ of aerobic cellular respiration is catalyzed by pyruvate dehydrogenase
intermediate stage
the net energy output of glycolysis is _____ molecules of ATP and _____ molecules of NADH
2/2
the enzymes of the electron transport system are located in the _____ membrane of mitochondrion
inner
a carbon and two oxygens are removed from pyruvate in a process known as
decarboxylation
how many molecules of NAD+ are reduced from the energy in one glucose molecule during the intermediate stage of glucose oxidation?
2
oxaloacetic acid is involved in the _____ step of the citric acid cycle and is regenerated in the _____ step
first/last
by the end of the citric acid cycle, the carbon atoms of glucose have been transferred to
carbon dioxide
the set of proteins in the cristae of the mitochondrion which collectively extract the energy from reduced coenzymes to form ATP are called the
electron transport system
the series of electron carriers in the cristae of the mitochondrion is collectively called the
electron transport chain
the energy from 2 ATP molecules is consumed during glucose oxidation. what is the energy used for?
to transport NADH
which makes the most efficient use of the energy in glucose?
aerobic respiration
if the electron transport chain does not oxidize NADH to NAD+, what may happen to glycolysis?
it may eventually stop
what is the set number of ATP molecules that can be produced from the oxidation of a glucose molecule under anaerobic conditions?
2
in order to form lactic acid, H+ is transferred from _____ to _____
NADH/pyruvate
why does pyruvate need to be converted to lactic acid in order for glycolysis to continue in the absence of oxygen?
in the absence of oxygen, NADH is not converted to NAD+ by the electron transport chain, and NAD+ levels fall
true or false: extracting energy from fatty acids to make ATP always requires oxygen
true
the type of amino acids that may enter glycolysis, the intermediate stage, and the citric acid cycle at different points are _____ amino acids
deaminated
the hydrogen atoms needed to convert pyruvate to lactic acid comes from
NADH
_____ is the process used to convert fatty acids to acetyl coa
beta-oxidation
the reduced product in an oxidation-reduction reaction has become _____ negative in charge by the addition of an electron
more
NADH is the reduced form of NAD+ because
NAD+ has gained both a H+ ion and 2 electrons
when electrons move during an oxidation-reduction reaction, they possess _____ energy that can be used to do _____
kinetic/work
the formation of ATP from ADP and Pi is an example of a(n)
endergonic reaction
if carbon dioxide is removed from CO2 + H2O <--> H2CO3, the amount of carbonic acid will
decrease
what conditions will increase the rate of a chemical reaction?
increased reactant concentration, increased temperature, and addition of a catalyst
increasing the temperature will _____ the rate of a chemical reaction by _____ the kinetic energy of the reactants
increase/increasing
the temperature at which an enzyme functions most efficiently is the
optimal temperature
a(n) _____ binds to an enzyme to stop its action
inhibitor
a(n) _____ binds to a site apart from the active site to prevent an enzyme from catalyzing a reaction
noncompetitive inhibitor
how does a noncompetitive inhibitor affect enzyme action?
binding to an allosteric site causes a conformational change
how are metabolic pathways usually regulated?
negative feedback
true or false: the enzymes in a multienzyme complex can be spread throughout a cell
false
an advantage of clustering enzyme by addition of a phosphate is referred to as
phosphorylation
an enzyme that regulates the activity of another enzyme by removing a phosphate group is called a
phosphatase
the products produced by one enzyme of a metabolic pathway can act as _____ of another enzyme
allosteric inhibitors
the binding of a noncompetitive inhibitor induces a _____ change in an enzyme
conformational
a progressive change in substrate molecules catalyzed by a series of enzymes is referred as a(n)
metabolic pathway
if multiple enzymes in a metabolic pathway are physically attached to each other, they form a
multienzyme complex
the process of removing a phosphate is
dephosphorylation
true or false: competitive inhibitors do not resemble substraets
false
the greater the amount of a competitive inhibitor the _____ likely a substrate is to occupy the active site of an enzyme
less
an enzyme that is catalyzing a reaction at the maximum rate is said to be
saturated
citric acid cycle in order
acetyl coa --> citrate --> isocitrate --> alpha-ketoglutarate --> succinyl coa
which of these effects on enzymes and their function can result from changes in pH?
denaturation, changes in H+ associated with an enzyme, changes in enzyme structure
the temporary structure formed when an enzyme binds to a substrate is known as an
enzyme substrate complex
_____ is a multistep process in which organic molecules like glucose, fatty acids, and amino acids are broken down to exact energy for ATP production
cellular respiration
which are typical locations of enzymes?
within the cellular cytosol and embedded in the plasma membrane
a molecule that assists an enzyme is performing its function is known as a(n)
cofactor
examples of cofactors
NAD+, zinc, vitamin b12
an organic cofactor is known as a(n)
coenzyme
the names of most enzymes end with the suffix
-ase
which condition will likely increase enzyme activity?
mild fever
what would be the likely result of severe fever or hypothermia?
enzyme denaturation
pancreatic amylase is _____ into the lumen of the small intestine, while lactase is found in the _____ of intestinal cells
released/plasma membranes
most enzymes are capable of catalyzing _____ type(s) of reaction(s)
one
intermediate substrates of glycolysis
glucose --> glucose 6-p --> fructose 6-p --> fructose 1,6-p --> glyceraldehyde 3-p
glucose _____ is the step-by-step breakdown of glucose to release energy for the synthesis of ATP
oxidation