Module 3
When an electron in a pigment molecule is absorbed by a photon, it ____.
) emits its extra energy and returns to its original energy level
The activation energy could be defined as
) the energy input needed to start the reaction
thermodynamics is the study of
*NOT* WORK AND ITS FORMS
A chemical reaction which releases more energy than it consumes, the break down of ATP to ADP for instance, is called
1) an exergonic (=exothermic) reaction
A chemical reaction which releases more energy than it consumes, the break down of ATP to ADP for instance, is called Question options:
1) an exergonic (=exothermic) reaction
Allosteric enzymes ____.
1) have regions that bind with inhibitor or activator molecules
The electron transfer chain is located ____.
1) on the inner membrane of the mitochondria
Which of the following is true for endergonic reactions?
1) the input of energy is required
For each glucose molecule broken down in anaerobic respiration, how may ATPs are produced?
2
Which of the following are the final product of glycolysis?
2 molecules of pyruvate
What is a key characteristic of enzyme behavior?
2) The active site of an enzyme orients its substrate molecules, thereby promoting interaction of their reactive parts.
When molecules are broken apart in respiration, ____. Question options:
3) the energy released is channeled into molecules of ATP
All of the following statements are corollaries of the Second Law of Thermodynamics except Question options: 1) Heat energy represents lost energy to most systems. 2) Systems tend to rearrange themselves to accommodate an increase in entropy. 3) Highly organized systems require energy for their maintenance. 4) The total amount of free energy in the universe is constant.
4
Which statement below characterizes metabolic pathways?
4) They are enzyme-mediated sequences of reactions.
The activation energy of a reaction refers to the minimum amount of energy ____.
4) necessary to cause a reaction to proceed on its own
With regard to photosynthesis, photorespiration ____. 1) is more efficient in producing carbohydrates 2) predominates in C3 plants in cool weather when water is plentiful 3) predominates in C4 plants on hot days 4) produces the same amount of PGA 5) is less efficient in producing carbohydrates
5) is less efficient in producing carbohydrates
CO2 and H2O will not form glucose on their own because ____.
5) the bonds of CO2 and H2O are too stable to be broken without an input of energy
fluid mosaic model
A composition of phospholipids, proteins, sterols, and glycolipids
second law
A cup of hot coffee cooling over time
first law
A hydroelectric plant at a waterfall, producing electricity
The light-dependent reactions of photosynthesis produce
ATP and NADPH
created, destroyed
According to the first law of thermodynamics, energy can neither be ________ nor ________ .
oxidizes
Aerobic respiration ________ organic compounds to form ATP.
entropy
All natural processes proceed with an increase in ________ of the universe.
first law
Apple trees absorbing energy from the sun and storing the energy in the chemical bonds of starch and sugar
three
As the first step in glycolysis, two _____-carbon molecules are produced.
receptor proteins
Bind extracellular substances that trigger changes in the cell's activity
What is the source of carbon for the dark reactions?
C02
Bread rises from the _____ produced during alcohol fermentation.
CO2
What is the source of carbon for the dark reactions?
CO2
energy
Calories are units to measure
enzyme
Cells regulate ________ activity in order to control how much substrate is used and how much reaction product is made during metabolism.
second law
Earth's sun continuously losing energy to its surroundings
coupled
Endergonic and exergonic reactions are frequently _______ in cells.
2
For each glucose molecule broken down in anaerobic respiration, how may ATPs are produced?
glucose
Glycolysis depends upon a continuous supply of NAD+ and ____.
adhesion proteins
Help cells of the same type stick together
two
How many ATP are spent before a glucose molecule can be broken down to release energy?
2
How many NADH molecules are formed during glycolysis?
ADP and Pi
Hydrogen ions flowing through the ATP synthases provide energy to combine
slowed
If the pH of the environment is above the enzyme's optimal value, the rate of the enzymatic reaction will be
water
In addition to ATP, the final stage of aerobic respiration also produces ________ .
b. the molecule that accepts electrons is reduced
In oxidation-reduction reactions, ____.
entropy
In the science of thermodynamics, the property of randomness is also referred to as
motion
Kinetic energy is the energy of
pyruvate
Lactate fermentation transfers the electrons and hydrogen ions carried by NADH directly to ____.
photosystem II
Light energy is absorbed by which structure within the thylakoid membrane
chemical transformations
Metabolism is all of the _________ in living organisms.
catalysts
Most enzymes act as ________ because they lower the energy of activation of a chemical reaction.
Most eukaryotes make ATP by aerobic respiration which breaks down organic molecules such as carbohydrates. aerobic respiration begins with gylcolysis , a reaction that converts one molecule of glucose to two molecules of pyruvate . Aerobic respiration ends in the mitochondria and yields about 36 molecules of ATP per two . An alternate pathway, fermentation , is common in microorganism and does not require oxygen . It also begins with glycolysis but produces only two molecules of ATP.
Most eukaryotes make ATP by aerobic respiration which breaks down organic molecules such as carbohydrates. aerobic respiration begins with gylcolysis , a reaction that converts one molecule of glucose to two molecules of pyruvate . Aerobic respiration ends in the mitochondria and yields about 36 molecules of ATP per two . An alternate pathway, fermentation , is common in microorganism and does not require oxygen . It also begins with glycolysis but produces only two molecules of ATP.
The compound(s) which donate electrons to the electron transport system are
NADH and FADH2
the sun
Nearly all life on Earth obtains its energy from
Your muscles get sore during a workout because
O2 becomes depleted and you produce lactate
The first stable compound produced from CO2 in the light-independent reaction is ____.
PGA
Lactate fermentation transfers the electrons and hydrogen ions carried by NADH directly to ____.
Pyruvate
a substrate
Substrate-level phosphorylation transfers phosphate groups directly from ____ to ADP.
in the stroma
Sugars are formed in the chloroplasts ____.
F
T OR F: Energy flows from photosynthesis to anaerobic respiration in a one-way direction.
true
The amount of low-quality energy in the universe is decreasing.
blue-violet
The best light to grow the alga in is ____, according to the figure.
proteins
The breakdown of ____ for energy production results in the formation of ammonia as a waste product.
pyruvate
The breakdown of ____ yields acetyl-CoA and carbon dioxide.
oxaloacetate
The final step of the Krebs cycle regenerates ____.
constant
The first law of thermodynamics states that the entropy of the universe is
first law
The glow of an incandescent bulb following the flow of electrons through a wire
Calvin-Benson, stroma, ATP, NADPH, rubisco, RuBP, PGA, ATP, NADPH, PGAL, glucose.
The light-independent reactions of the Calvin-Benson cycle build sugars in the stroma of chloroplasts. They run on _____ and _______ , molecules made in the light-dependent reactions. During carbon fixation, the enzyme rubisco is used to attach CO2 to a five-carbon molecule . The resulting unstable six-carbon molecule splits into two three-carbon molecules . A phosphate group from ATP and hydrogen and electrons from NADPH transform each molecule of PGA into a molecule of PGAL . Two carbon PGAL molecules combine to form larger carbohydrates .
cholesterol
The main steroid component of animal membranes
atp
The molecule often called the energy currency of the cell is
phospholipids
The primary component of the cell membrane; consists of both hydrophobic and hydrophilic regions
What statement is an application of the first law of thermodynamics?
The quantity of energy does not increase or decrease in the universe.
metabolism
The sum total of the chemical activity at the cellular level which enables an organism to meet its nutrient and energy demands is termed the organism's
2
There are _____ acetyl-CoA molecules are produced per glucose molecule.
oxygen
What is NOT a product of the light-independent reactions?
NADPH
What is a required input for the light-independent reactions?
NADPH and ATP
What is formed during the light dependent reactions of photosynthesis?
atp
What is present in both the light-dependent and light-independent reactions?
1, 3, 2
What is the correct operational sequence of the three processes listed below? I. glycolysis II. electron transport chain III. Krebs cycle
aerobic respiration
What process requires oxygen to function?
potential
What type of energy is the energy in chemical bonds?
NADPH
When NADP+ and a hydrogen ion combine, which molecule is fromed?
the mitochondria
When pyruvic acid becomes broken down into CO2 and H20, this occurs within
Sunlight
Where does most of the energy that fuels life come from originally?
water
Where does the oxygen liberated by plants in photosynthesis come from?
cytoplasm
Where in a cell does glycolysis occur?
RuBP
Which chemical has five carbon atoms?
RuBp
Which chemical has five carbon atoms?
ATP
Which of the following are products of the light depednent reactions that are sent to the light independent reactions
2 molecules of pyruvate
Which of the following are the final product of glycolysis?
NADPH
Which of the following are the products of the light-dependent reactions that are sent to the light-independent reactions?
red
Which of the following colors of light is absorbed most by the chlorophyll molecules?
fructose
Which of the following is not part of an ATP molecule?
glycolysis
Which of the following sets of reactions would you find in the cytoplasm of a cell?
c4
Which plant(s) overcome the inefficiencies of photorespiration through a secondary carbon fixation process?
carbon fixation
________ is the process of converting inorganic carbon to an organic molecule.
energy is the
ability to do work
Phosphorylation is the _______ of a phosphate group to a molecule
addition
What process requires oxygen to function?
aerobic respiration
NADP+ and a hydrogen ion
after passing through an electron transfer chain, the high-energy electrons are used to combine which of the following two molecules?
oxygen is not needed, so it diffuses out of the cell
after water is broken down, hydrogen ions remain in the chloroplast to be used in chemical reactions
Which of the following are able to enter cellular respiration to provide the cell energy? Question options: 1) carbohydrates 2) lipids 3) proteins 4) all of the above can enter the cellular respiration reactions
all of the above
Many enzyme regulators are molecules which can regulate enzyme activity by binding to a(n) ______ site and thereby altering the shape of the ________ site on the enzyme.
allsoteric, active
A chemical reaction which releases more energy than it consumes, the break down of ATP to ADP for instance, is called
an exergonic (=exothermic) reaction
The molecule often called the energy currency of the cell is
atp
Allosteric inhibition generally results from ____.
binding of regulatory molecules at sites other than the active sites
The best light to grow the alga in is ____, according to the figure.
blue-violet
the most common unit used to measure the energy of biological systems is the
calorie
Which of the following are the raw materials for photosynthesis?
carbon dioxide and water
According to the first law of thermodynamics, ____.
chemical reactions do not create or destroy energy
Leaves of plants appear green because their _____ green light.
chlorophylls reflect (or transmit)
One reason that metal ions and vitamins are needed by many organisms is that these substances are used as _______ in enzyme functioning.
cofactors and coenzymes
When a molecule binds to an enzyme's active site and inhibits the enzyme's activity, the situation is called
competitive inhibition
Question 11 2 / 2 points Endergonic and exergonic reactions are frequently _______ in cells.
coupled
The type of reaction depicted above could be _________ in your cells.
coupled with the reaction ATP -> ADP + energy
In the respiration rate experiment, which organism had the highest rate of respiration?
crickets
Where in a cell does glycolysis occur?
cytoplasm
When a 'high energy' bond of ATP is broken, the released energy usually
drives an endergonic reaction
During the light reactions, _____ are pumped into the thylakoid's membranes.
electrons
the second law of thermodynamics states that
energy tends to flow from concentrated to less concentrated forms
The second law of thermodymanics states that the _________ of the universe is increasing.
entropy
Which of the following has the greatest amount of energy per gram?
fats
Which of the following has the greatest amount of energy per gram? Question options:
fats
The formation of lactate by muscle cells during ATP production is an example of a type of metabolism called
fermentation
Yeasts carry out a form of anaerobic respiration known as alcoholic .
fermentation
The C4 pathway ____.
fixes carbon twice
A "high-energy bond" in ATP ____.
forms as part of an endergonic reaction
ATP
frequently participates in coupled reactions
Reduction is the
gain of electrons
Glycolysis depends upon a continuous supply of NAD+ and ____.
glucose
The starting substance for glycolysis is
glucose
Which of the following has the greatest total energy?
glucose
Which of the following has the most energy?
glucose
Pyruvate is the end product of ____.
glycolysis
The metabolic process common to both aerobic and anaerobic respiration is
glycolysis
Allosteric enzymes ____.
have regions that bind with inhibitor or activator molecules
In 1985 a Union Carbide plant in Bhopal, India, leaked methyl isocyanate (cyanide) into the atmosphere. More than 2000 people died within a few minutes. Research has shown that cyanide blocks one of the final reactions in the electron transport chain, stopping it. If you were an investigator working for a lawyer representing the victim's families, which of the following would you tell her would help to prove that cyanide killed these people?
high concentrations of lactic acid in the cells
the electron transfer chain
high-energy electrons that are ejected from photosystem II enter a series of reactions called
During chemiosmosis, _____ ions are pumped across the inner mitochondrial membrane to produce ATP.
hydrogen
stroma
hydrogen ions flow through structures in the thylakoid membrane called ATP synthases. they flow from the thylakoidcompartment into the
high-energy electrons in the electron transfer chain
hydrogen ions move into the thylakoid compartment using energy from which of the following?
flow back out of the thylakoid compartment
hydrogen ions power the formation of ATP as they
noncyclic pathway
if a photosynthetic cell is running low on NADPH, should it use the cyclic pathway or the noncyclic pathway of the light-dependent reactions?
electron transfer chain
in the cyclic pathway, electrons pass through the
Glycolysis occurs
in the cytoplasm
In plant cells, chloroplasts are found ____.
in the cytoplasm of the cell
thylakoid membrane
in the electron transfer chain, high energy electrons are passed through the
Sugars are formed in the chloroplasts ____.
in the stoma
Increasing the amount of ratio of enzyme to substrate molecules in a mixture will
increase the rate of reaction
An enzyme is thought to optimize the fit between substrates by restraining and stretching or squeezing them into certain shapes and moving them to the transition state, as described by the ____ model of enzyme activity.
induced-fit
The _________ model of the enzyme-substrate complex suggests that the active site is flexible and its shape can change in order to produce an optimal fit between the enzyme and substrate molecules.
induced-fit
Noncylic pathway
is a one way flow of electrons from water, to photosystem II, to photosystem I, to NADPH. Energy is released as electrons move through the first electron transfer chain. This energy pumps hydrogen ions into the thylakoid compartment.
The optimal temperature of an enzyme
is different for different enzymes
With regard to photosynthesis, photorespiration ____.
is less efficient in producing carbohydrates
activation energy
is the energy input needed to start the reaction
blue leaf
is the right one, background tan
Approximately 41% of the energy in glucose is used to make ATP. What happened to the other 59%?
it is lost as heat
The tangy taste of yogurt occurs because bacteria produce
lactate
Which of the following is the largest abiotic source of energy for living organisms on earth?
light energy from the sun
Thylakoid membrane
light-dependent reactions occur in which of the following structures within the plant cell
Oxidation is the
loss of electrons
The sum of all chemical reactions in an organism refers to its
metabolism
The proteins associated with the light-dependent reactions of photosynthesis are located ____.
on the thylakoid membrane
Where do photosystems I and II occur?
on the thylakoid membrane
cyclic pathway
only uses photosystem I
enthalpy is the total __ of a system
potential energy
what type of energy is the energy in chemical bonds
potential energy
The breakdown of ____ for energy production results in the formation of ammonia as a waste product.
proteins
All the energy utilized by living organisms is ultimately
released into space in the form of heat
All the energy utilized by living organisms is ultimately
released to space in the form of heat
Endergonic reactions ____.
require a net input of energy
Fats provide more energy than carbohydrates because they ____.
require more oxidation reactions to breakdown fully
In some cases, inhibitors or activators of enzyme-catalyzed reactions act by ____.
reversibly binding to an enzymes allosteric site
The ____ a photonâs wavelength, the ____ its energy.
shorter, greater
An enzyme lowers activation energy by ____.
shutting out water molecules
Decreasing the amount of ratio of enzyme to substrate molecules in a mixture will
slow the rate
The fluid filled region found in chloroplasts is called the
stroma
The dark reactions of photosynthesis take place in the
stroma of chloroplasts
t
t or f: The Kreb's Cycle is the second step in aerobic respiration.
The shape of an enzyme's active site is determined by its
tertiary structure
fixes carbon twice
the c4 pathway
During photosynthesis, which process fixes carbon dioxide?
the calvin cycle
thylakoid compartment
the energy released from this pumps hydrogen ions into the
C4 photosynthesis is advantageous to plants growing in hot, dry regions because
the enzyme which fixes CO2 has a high affinity for CO2
The total amount of energy in a closed system is constant. This is a statement of
the first law of thermodynamics
After carbon fixation in C4 plants, the first stable compound produced is
the four carbon compound oxaloacetate
The enzymes which catalyze the reactions of the Krebs cycle are found in
the mitochondria
When pyruvic acid becomes broken down into CO2 and H20, this occurs within
the mitochondria
In oxidation-reduction reactions, ____.
the molecule that accepts electrons is reduced
In oxidation-reduction reactions, ____.
the molecule that accepts electrons is reducedlecule that accepts electrons is reduced
electrons
the non-cyclic pathway is a one-way flow of ______ from molecules of water to
NADPH
the non-cyclic pathway is a one-way flow of electrons from molecules of water to blank, to photosystem 1, to
If the structure of the mitochondrial membrane was disrupted, which of the following metabolic processes would be most significantly effected?
the production of ATP from NADH and FADH2
Which of the below graphs best illustrates the trends of enzyme activity at various pH environments?
the upside down u graph
In 1985 a Union Carbide plant in Bhopal, India, leaked methyl isocyanate (cyanide) into the atmosphere. More than 2000 people died within a few minutes. Research has shown that cyanide blocks one of the final reactions in the electron transport chain, stopping it. These people died because
their cells could produce some ATP but not enough to sustain life
Which statement below characterizes metabolic pathways?
they are enzyme-mediated sequences of reactions.
In the respiration rate experiment, which of the following is the best explanation for testing the dry peas?
they served as the control
The structural unit for the light reactions of photosynthesis is the
thylakoid
The active site of an enzyme is the region
to which substrate molecules bind
How many ATP are spent before a glucose molecule can be broken down to release energy?
two
One molecule of FADH2 generated during the citric acid cycle can be converted to ___ ATP molecules during electron transport and chemiosmosis.
two
noncyclic pathway
uses both photosystems I and II
In the electromagnetic spectrum, ____.
visible light provides the energy for photosynthesis
water
which molecule does photosystem II pull replacement off of
high-energy electrons
which of the following is ejected from photosystem I?
atp only
which of the following is the end product of the cyclic pathway
electrons are continuously recycled and do not need to be replaced
which of the following statements describes the cyclic pathway?
electrons are lost to NADP+ and must be repalced
which of the following statements describes the noncyclic pathway
sunlight
while they were in the photosystem, the high-energy electrons were "charged up" with energy from what source
Cellular respiration is a gradual, multistepped process. This is so
your cells have the opportunity to transform the energy into chemical bonds
o2 and atp
During the third stage of aerobic respiration, electrons and hydrogen ions released by the reactions of the first two stages are picked up by ____.
the energy released is channeled into molecules of ATP
When molecules are broken apart in respiration, ____.