Chapter 9 Mastering Bio

In cells, what is usually the immediate source of energy for an endergonic reaction? glucose ADP ATP sugar as spontaneous reactions, endergonic reactions do not need an addition of energy

ATP

The energy for an endergonic reaction comes from a(n) _____ reaction. anabolic exergonic glucose + glucose --> maltose synthesis ADP + P --> ATP

Exergonic

1. When a compound donates (loses) electrons, that compound becomes oxidized. Such a compound is often referred to as an electron donor. 2. When a compound accepts (gains) electrons, that compound becomes reduced. Such a compound is often referred to as an electron acceptor. 3. In glycolysis, the carbon-containing compound that functions as the electron donor is glucose. 4. Once the electron donor in glycolysis gives up its electrons, it is oxidized to a compound called pyruvate. 5. NAD+ is the compound that functions as the electron acceptor in glycolysis. 6. The reduced form of the electron acceptor in glycolysis isNADH.

Fill in the blanks

Ethanol catabolism in the body begins with its oxidation (dehydrogenation), with NAD+ as the electron acceptor. The more ethanol is consumed, the greater the demand is for NAD+ and the more serious is the reduction in NAD+ concentration. The supply of NAD+ may be inadequate for aerobic respiration of glucose.

Fill in the blanks

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. It is used to convert an ATP into an AQP. It is acquired by a reactant in an exergonic reaction. It is acquired by a reactant in a spontaneous reaction. It is broken down into one phosphorus and four oxygen atoms.

It is acquired by a reactant in an endergonic reaction.

The medical treatment for methanol poisoning usually involves administration of large doses of ethanol. Why is this treatment effective? -Methanol and ethanol are both substrates of the enzyme alcohol peroxidase.The body is flooded with a large amount of ethanol to provide an effective competitor of methanol, thereby minimizing the production of formaldehyde. -Methanol and ethanol are both substrates of the enzyme alcohol dehydrogenase.The body is flooded with a large amount of ethanol to provide an effective competitor of methanol, thereby minimizing the production of acetaldehyde. -Methanol and ethanol are both substrates of the enzyme alcohol peroxidase.The body is flooded with a large amount of ethanol to provide an effective competitor of methanol, thereby minimizing the production of acetaldehyde. -Methanol and ethanol are both substrates of the enzyme alcohol dehydrogenase.The body is flooded with a large amount of ethanol to provide an effective competitor of methanol, thereby minimizing the production of formaldehyde.

Methanol and ethanol are both substrates of the enzyme alcohol dehydrogenase.The body is flooded with a large amount of ethanol to provide an effective competitor of methanol, thereby minimizing the production of formaldehyde.

The overall energy yield for glucose is greater by one ATP when it is catabolized from a polysaccharide rather than a free sugar. This is true because __________. -stored glucose enters the glycolytic cycle as fructose-6-phosphate -polysaccharides can be processed directly into the electron transport chain -polysaccharides already contain ATP -energy comes from the process of breaking down the polysaccharide

energy comes from the process of breaking down the polysaccharide

A(n) _____ reaction occurs spontaneously. endergonic kinetic chemical anabolic exergonic

exergonic

The reaction A --> B + C + heat is released in a(n) _____ reaction. exergonic anabolic exchange dehydration synthesis endergonic

exergonic

Select the INCORRECT association. exergonic ... spontaneous kinetic energy ... motion enzyme ... protein exergonic ... uphill potential energy ... positional energy

exergonic ... uphill

The reaction ADP + P --> ATP is a(n) _____ reaction. exergonic hydrolysis chemical endergonic spontaneous

endergonic

Which of these reactions requires a net input of energy from its surroundings? catabolic ATP --> ADP + P endergonic hydrolysis exergonic

endergonic

Among the products of glycolysis, which compounds contain energy that can be used by other biological reactions? -O2 only -CO2 only -pyruvate and ATP only -NADH only -pyruvate, ATP, and NADH -ATP only -ATP and NADH only

-pyruvate, ATP, and NADH

Much of the suitability of ATP as an energy intermediary is related to the instability of the bonds between the phosphate groups. These bonds are unstable because __________. -the phosphate groups are polar and are attracted to the water in the interior of a cell -the valence electrons in the phosphorus atom have less energy on average than those of other atoms -the negatively charged phosphate groups vigorously repel one another -they are hydrogen bonds, which are only about 10% as strong as covalent bonds

-the negatively charged phosphate groups vigorously repel one another

Mannose, galactose, and fructose all enter glycolysis at either the first or the third step of the pathway. Which of the following accurately states the advantage of this design? -This prevents the buildup of lactate. -This allows for more ATP to be made per sugar. -This allows for the sugars to be converted into glucose. -This allows the metabolism of these sugars to be regulated.

This allows the metabolism of these sugars to be regulated.

A chemist has discovered a drug that blocks phosphoglucoisomerase. This drug would NOT be a good antibacterial treatment for human use because __________. -glycolysis produces so little ATP that the drug will have little effect -human cells also perform glycolysis, so the drug might also poison them -bacteria are facultative anaerobes, so they don't need to perform glycolysis -bacteria do not perform glycolysis

human cells also perform glycolysis, so the drug might also poison them

What is energy coupling? a description of the energetic relationship between the reactants and products in an exergonic reaction the hydrolysis of ATP to ADP + P the use of an enzyme to reduce EA the use of energy released from an exergonic reaction to drive an endergonic reaction a barrier to the initiation of a reaction

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