bio hw questions

Which of these is exhibiting kinetic energy?

a space station orbiting Earth

"Conservation of energy" refers to the fact that _____.

energy cannot be created or destroyed but can be converted from one form to another

Chemical energy is a form of _____ energy.

potenial

In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?

cellular respiration

Which of these are by-products of cellular respiration?

heat, carbon dioxide, and water

A(n) _____ reaction occurs spontaneously.

exergonic

Which of these reactions requires a net input of energy from its surroundings?

endergonic

In cells, what is usually the immediate source of energy for an endergonic reaction?

atp

The reaction ADP + P --> ATP is a(n) _____ reaction.

endergonic

The energy for an endergonic reaction comes from a(n) _____ reaction.

exergonic

What is the fate of the phosphate group that is removed when ATP is converted to ADP?

It is acquired by a reactant in an endergonic reaction.

What is energy coupling?

the use of energy released from an exergonic reaction to drive an endergonic reaction

What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?

hydrolysis

In general, enzymes are what kinds of molecules?

proteins

Enzymes work by _____.

reducing activation energy

An enzyme _____.

is an organic catalyst

What name is given to the reactants in an enzymatically catalyzed reaction?

substrate

As a result of its involvement in a reaction, an enzyme _____.

is unchanged

Which of the following statements about the role of ATP in cell metabolism is true?

The energy from the hydrolysis of ATP may be directly coupled to endergonic processes by the transfer of the phosphate group to another molecule.

Consider a situation in which the enzyme is operating at optimum temperature and ph, and has been saturated with substrate. What is your best option for increasing the rate of the reaction?

increase the enzyme concentration

What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?

hydrolysis

An enzyme is when it loses its native conformation and its biological activity

denatured

An enzyme is considered a xxxxxbecause it speeds up chemical reactions without being used up.

catalyst

An enzyme is considered xxxxxx because of its ability to recognize the shape of a particular molecule.

specific

A xxxxxxx such as a vitamin, binds to an enzyme and plays a role in catalysis.

cofactor

When properly aligned, the enzyme and substrate form an enzyme-substrate (ES)

complex

A substrate binds to an enzyme at the

,xxxxxxxwhere the reaction occurs.

active site

In a catalyzed reaction a reactant is often called a

substrate

A reaction that occurs spontaneously - without an input of energy - is

exergonic

A reaction that occurs nonspontaneously - it requires an input of energy - is

endergonic

Exergonic reactions result in products that have less free energy than the reactants, thus free energy is released and change G is

negative

Endergonic reactions result in products that have more free energy than the reactants, thus free energy is absorbed and Upper Delta G is

positive

A cell can only carry out an xxxx reaction by pairing it with an

xxxx reaction, such as ATP hydrolysis.

endergonic, exergonic

Which part of the adenosine triphosphate molecule is released when it is hydrolyzed to provide energy for biological reactions?

y-phosphate

What would happen to the rate of the forward reaction if the concentration of nitrogen were decreased?

the reaction rate would decrease

What will happen to the rates of the forward and reverse reactions when a catalyst is added?

both forward and reverse rates increase

A(n) xxxx inhibitor has a structure that is so similar to the substrate that it can bond to the enzyme just like the substrate.

competitive

A(n) xxxx inhibitor binds to a site on the enzyme that is not the active site.

noncompetitive

The competitive inhibitor competes with the substrate for the xxxxx on the enzyme.

active site

When the noncompetitive inhibitor is bonded to the enzyme, the shape of the is distorted.

enzyme

Enzyme inhibitors disrupt normal interactions between an enzyme and its

substrate

Which term describes the degree to which an element attracts electrons?

electronegativity

Which terms describe two atoms when they form a bond in which electrons are completely transferred from one atom to the other?

anion and cation

Which of the following statements is true of the bonds in a water molecule?

Oxygen holds electrons more tightly than hydrogen does, and the net charge is zero.

What kind of bond is formed when lithium and fluorine combine to form lithium fluoride?

ionic

Gaseous hydrogen burns in the presence of oxygen to form water: 2H₂ + O₂——>2H₂O+ energy

Which molecule is oxidized and what kind of bond is formed?

hydrogen, polar

glycolsis occurs

cytosol

acetyl coa formation

mitochondrial matrix

citric acid cycle

mitochondrial matrix

oxidative phosphorylation

inner mitochondrial membrane

How many NADH are produced by glycolysis?

2

In glycolysis, ATP molecules are produced by _____.

substrate level phosphorylation

Which of the following are products of glycolysis?

pyruvate, nadh, atp

What energy source is required during glycolysis?

atp

In glycolysis, there is a net gain of how many ATP?

2

Which of these enters the citric acid cycle?

acetyl coa

In the citric acid cycle, ATP molecules are produced by _____.

substrate level phosphorylation

Which of these are products of the citric acid cycle?

fadh2, co2

Which molecule is metabolized in a cell to produce energy for performing work?

glucose

True or false? The potential energy in an ATP molecule is derived mainly from its three phosphate groups.

true

Which process is not part of the cellular respiration pathway that produces large amounts of ATP in a cell?

fermentation

Which step of the cellular respiration pathway can take place in the absence of oxygen?

glycolysis

Into which molecule are all the carbon atoms in glucose ultimately incorporated during cellular respiration?

carbon dioxide

Which of the following statements about the electron transport chain is true?

NADH and

FADH

₂

donate their electrons to the chain.

Which stage of glucose metabolism produces the most ATP?

Electron transport and chemiosmosis

True or false? The reactions that generate the largest amounts of ATP during cellular respiration take place in the mitochondria.

true

In mitochondrial electron transport, what is the

direct role of Upper O 2?

to function as the final electron acceptor in the electron transport chain

How would anaerobic conditions (when no 

Upper O 2 is present) affect the rate of electron transport and 

ATP production during oxidative phosphorylation? (Note that you should

not consider the effect on ATP synthesis in glycolysis or the citric acid cycle.)

Both electron transport and  ATP synthesis would stop.

Under anaerobic conditions (a lack of oxygen), the conversion of pyruvate to acetyl CoA stops.

Which of these statements is the correct explanation for this observation?

In the absence of oxygen, electron transport stops. NADH is no longer converted to NAD⁺,which is needed for the first three stages of cellular respiration.

Among the products of glycolysis, which compounds contain energy that can be used by other biological reactions?

pyruvate, ATP, and NADH

For each glucose that enters glycolysis, _____ acetyl CoA enter the citric acid cycle.

2

For each glucose that enters glycolysis, _____ NADH + H⁺are produced by the citric acid cycle.

6

In cellular respiration, most ATP molecules are produced by _____.

oxidative phosphorylation

The final electron acceptor of aerobic cellular respiration is _____.

oxygen

During electron transport, energy from _____ is used to pump hydrogen ions into the _____.

nadh and fadh2….. intermembrane space

If a mitochondrion ran out of molecular oxygen (O₂),predict which of the following situations would occur in its electron transport chain.

FMN prosthetic groups would remain reduced and NADH would have nowhere to donate electrons.

In muscle cells, fermentation produces _____.

lactate and NAD⁺

In fermentation _____ is reduced and _____ is oxidized.

pyruvate, nadh

The light reactions of photosynthesis use _____ and produce _____.

water ... NADPH

For every molecule of O₂that is released by photosystem II, H₂O molecules are needed, which together pass

electrons to the PS II reaction-center complex.

2,4

If the Calvin cycle slows down, what will happen to the rate of O₂production in PS II, and why?

O₂production will slow down because less NADP⁺will be regenerated in the Calvin cycle.

Which process produces oxygen?

photosynthesis

Which set of reactions uses

H

₂

O

and produces

O

₂

?

the light dpeendent reaction

What is the importance of the light-independent reactions in terms of carbon flow in the biosphere?

The light-independent reactions turn

CO

₂

,

a gas, into usable carbon in the form of sugars.

True or false? The light-dependent reactions of photosynthesis use water and produce oxygen.

true

The excited electrons from Photosystem I are used to produce ___________.

nadph

What is the biological significance of the light-independent reactions of photosynthesis?

they convert carbon dioxide to sugaqr

Which of the following statements best describes the relationship between the light-dependent and light-independent reactions of photosynthesis?

The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions.

Which molecule is regenerated in the regeneration phase of the Calvin cycle? Without regeneration of this molecule, the Calvin cycle would stop.

rubp

Carbon fixation involves the addition of carbon dioxide to _____.

rubp

After 3-PGA is phosphorylated, it is reduced by _____.

nadph

How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose?

6

In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules?

3