AP Bio Chapter 6

What is ATP made from?

ADP + phosphate

When cellular respiration occurs, what is the primary molecule used to store the energy that is released?

ATP

How does ATP supply energy to chemical reactions?

ATP dissociates and the energy released by breaking of a phosphate bond within ATP is used for phosphorylation of another molecule. ATP hydrolysis also provides energy to power coupling reactions.

What reaction will release the largest amount of energy to help power another reaction?

ATP to ADP

Which of the following comparisons or contrasts between endergonic and exergonic reactions is false?

Endergonic reactions are not spontaneous and exergonic reactions are spontaneous

How do chemical reactions play a role in energy transfer?

Energy from the breakdown of glucose and other molecules in animals is released as ATP, which transfer energy to other reactions.

If a chemical reaction could occur without an enzyme, why is it important to have one?

Enzymes are important because the products are obtained consistently with time.

How does enzyme feedback inhibition benefit a cell?

Feedback inhibition benefits the cell by blocking the production of the products by changing the configuration of enzymes. This will prevent the cells from becoming toxic.

What is the underlying principle that supports the idea that all living organisms share the same core processes and features?

Glucose is the primary source of energy for all cellular functions.

Energy transfers take place constantly in every day activities. Think of two scenarios: cooking on a stove and driving. Explain how the second law of thermodynamics applies to these scenarios.

Heat is lost into the room while cooking and into the metal of the engine during gasoline combustion.

What does it mean for a system to be in a higher level of entropy? How can it be reduced?

Higher level of entropy refers to higher state of disorder in the system and it can be reduced by input of energy to lower the entropy.

Why is ATP considered the energy currency of the cell?

It can transport energy from chemical reactions.

Name two different cellular functions that require energy.

Phagocytosis helps amoebae take up nutrients and pseudopodia help the amoebae move.

Water deficiency is arguably the easiest deficiency to detect in plants. This is because plants that are lacking water will wilt, as water within the plant's cells helps to supports the plant's weight. Plant cells become water deficient because their cells use the water for metabolic processes. What happens to the metabolism of a plant that does not have adequate water?

Photosynthesis is inhibited, less glucose is produced, and water used by the cells is not replaced.

Plants must have adequate resources to complete their functions. If they do not have what they need, there are changes in the organism's metabolism. What happens to the metabolism of a plant that does not have adequate sunlight?

Photosynthesis slows and less glucose is produced for energy use.

Does physical exercise involve anabolic processes, catabolic processes, or both? Give evidence for your answer.

Physical exercise involves both catabolic and anabolic processes. Glucose is broken down into simpler compounds during physical activity. The simpler compounds are then used to provide energy to the muscles for contraction by the anabolic pathway.

Explain the conversion of energy that takes place when the sluice of a dam is opened.

Potential energy stored in the water held by the dam will convert to kinetic energy when it falls through the opening of the sluice.

It has been accepted that life on the Earth started out as single celled, simple organisms, which then evolved into complex organisms. How did evolution proceed to produce such a wide variety of living organisms from a simple ancestor?

Protists evolved first, then the prokaryotes, which branched into the fungi, plants, and animals

Imagine an elaborate ant farm with tunnels and passageways through the sand where ants live in a large community. Now imagine that an earthquake shook the ground and demolished the ant farm. In which of these two scenarios, before or after the earthquake, was the ant farm system in a state of higher or lower entropy? Why?

The ant farm is in the state of higher entropy after the earthquake, and energy must be spent to bring the system to low entropy.

What is true about the energy released by the hydrolysis of ATP?

The cell harnesses it as heat energy in order to perform work.

Enzymes facilitate chemical reactions that result in changes to a substrate. How does the induced fit model of enzymes and substrates explain their function?

The enzyme induces a change in the substrate, but is not changed itself during the reaction.

What is the difference between the first and second laws of thermodynamics?

The first law involves conserving energy while the second law involves the inability to recapture energy.

What happens if an enzyme is not functioning in a chemical reaction in living organism that needs it?

The reaction proceeds, but much more slowly.

Describe the position of the transition state on a vertical energy scale, from low to high, relative to the position of the reactants and products, for both endergonic and exergonic reactions.

The transition state of the reaction exists at a higher energy level than the reactants. Activation energy is always positive, regardless of whether the reaction is exergonic or endergonic.

An allosteric inhibitor does which of the following?

binds to an enzyme away from the active site and changes the conformation of the active site, decreasing its affinity for the substrate

Glucose is the sugar most often used in metabolism by the majority of cells on Earth. It is made and used by plants as well as other organisms. Which of the following describes the chemical breakdown of glucose, and what is the name of the chemical process involved in this breakdown?

cellular respiration: C6H12O6 + 6O2→6CO2+6H2O+energy

Enzyme inhibitors play an important part in the control of enzyme functions, allowing them to continue, or inhibiting them for a period of time. Which inhibitor affects the initial rate but do not affect the maximal rate?

competitive

Consider a pendulum swinging. Which type(s) of energy is/are associated with the pendulum in the following instances: 1. the moment at which it completes one cycle, just before it begins to fall back towards the other end. 2. the moment that it is in the middle between the two ends 3. just before it reaches the end of one cycle.

1. potential2. kinetic3. potential and kinetic

If glucose is broken down through aerobic respiration, a number of ATP can be made from the energy extracted. How many ATP are possible?

2 to 4

Plants make glucose through a pathway called photosynthesis. The amount of energy captured from light can be expressed as the number of energy containing molecules used to make one molecule of glucose. Which of the following best states the number of each molecule needed?

24 molecules of ATP and 18 molecules of NADPH

Cell metabolism is a complex process that uses many types of chemicals in a variety of processes. Which of the following statements is true?

A loss of enzymes would result in cell death.

Explain in your own words the difference between a spontaneous reaction and one that occurs instantaneously.

A spontaneous reaction is one which releases free energy and moves to a more stable state. Instantaneous reactions occur rapidly with sudden release of energy.

Which best describes the effect of inputting energy into a living system?

decreases entropy

Which of the terms in the Gibbs free energy equation denotes enthalpy?

delta H

Which of the following is a catabolic process?

digestion of sucrose

What type of reaction allows chemicals to be available for an organism's growth and maintenance in a timely manner? enzymatically facilitated reactions

enzymatically facilitated reactions

Which chemical reaction is more likely to occur?

exergonic

What food molecule used by animals for energy and obtained from plants is most directly related to the use of sun energy?

glucose

Which pair of descriptors of chemical reactions go together?

hydrolysis and exergonic

What counteracts entropy?

input of energy

Is the 𝐸AEA for ATP hydrolysis relatively low or high? Explain your reasoning.

low

Label each of the following systems as high or low entropy: 1. perfume the instant after it is sprayed into the air 2. an unmaintained 1950s car compared with a brand new car 3. a living cell compared with a dead cell.

lowhighlow

Which of the following molecules is likely to have the most potential energy?

sucrose

What is phosphorylation as it occurs in chemical reactions?

the attachment of a phosphate to another molecule to facilitate a chemical reaction

What part of ATP is broken to release energy for use in chemical reactions?

the bond between the second and third phosphates

What is the ultimate source of energy on the planet?

the sun

When the air temperature drops and rain turns to snow, which law of thermodynamics is exhibited?

third law of thermodynamics

What is the function of enzymes?

to lower the activation energy requirements of a reaction

What is an anabolic pathway? Which of these is an example of an anabolic pathway used by cells in their metabolism?

Anabolic pathways build new molecules out of the products of catabolic pathways. An example is the linkage of nucleotides to form a molecule of mRNA.

Describe the connection between anabolic and catabolic chemical reactions in a metabolic pathway.

Catabolic reactions produce energy and simpler compounds, whereas anabolic reactions involve the use of energy to make more complex compounds.

Which of the following is the best way to judge the relative activation between two given chemical reactions?

Compare their reaction rates.

Which of the following is not true about enzymes?

They increase the delta g of reactions.

Which of the following analogies best describe the induced-fit model of enzyme-substrate binding?

a hug between two people

Which of the following is the best example of the first law of themodynamics?

a power plant burning coal and producing electricity

Which of the following best describes energy?

ability to do work

Energy can be taken in as glucose, then has to be converted to a form that can be easily used to perform work in cells. What is the name of the latter molecule?

adenosine triphosphate

DNA replication involves unwinding two strands of parent DNA, copying each strand to synthesize complementary strands and releasing the resulting two semi-conserved strands of DNA. Which of the following accurately describes this process?

anabolic