Mastering Biology Chapter 8 and 10, Part 1

A(n) _____ reaction occurs spontaneously. 1. anabolic 2. chemical 3. exergonic 4. endergonic 5. kinetic

3. exergonic

_____ splits water into 1/2 O2, H+, and e- .

A

Which of these phosphorylates ADP to make ATP?

E

Which of the following is a statement of the first law of thermodynamics?

Energy cannot be created or destroyed.

What is the correct label for "A"? (How Enzymes Work, Reactants and Products)

Energy of Activation

True or false? The chemiosmotic hypothesis states that the synthesis of ATP generates a proton gradient that leads to electron flow through an electron transport chain.

False

True or false? The region of ATP synthase that catalyzes the production of ATP from ADP and inorganic phosphate spans the chloroplast membrane.

False

The process of cellular respiration, which converts simple sugars such as glucose into CO2 and water, is an example of _____.

a catabolic pathway

The graph presents three activation energy profiles for a chemical reaction (the hydrolysis of sucrose): an uncatalyzed reaction, and the same reaction catalyzed by two different enzymes. As the reaction progresses, energy rises and reaches the activation energy, then decreases to a value lower than in initial state. The activation energy for the uncatalyzed reaction is the greatest, for the reaction catalyzed by enzyme A it is lower, and the activation energy for the reaction catalyzed by enzyme B is the lowest. Rank these by reaction rate, as measured by the rate of product formation per unit time, from lowest reaction rate to highest reaction rate. To rank items as equivalent, overlap them.

(From lowest to highest) Uncatalyzed Reaction, Reaction catalyzed by enzyme A, Reaction catalyzed by enzyme B

Complete this vocabulary exercise relating to enzymes. Match the words in the left-hand column to the appropriate blank in the sentences in the right-hand column.

1. An enzyme is DENATURED when it loses its native conformation and its biological activity. 2. An enzyme is considered a CATALYST because it speeds up chemical reactions without being used up. 3. An enzyme is considered SPECIFIC because of its ability to recognize the shape of a particular molecule. 4. A COFACTOR, such as a vitamin, binds to an enzyme and plays a role in catalysis. 5. When properly aligned, the enzyme and substrate form an enzyme-substrate (ES) COMPLEX. 6. A substrate binds to an enzyme at the ACTIVE SITE, where the reaction occurs. 7. In a catalyzed reaction a reactant is often called a SUBSTRATE.

The following reaction A --> B + C + heat is a(n) _____ reaction. 1. exchange 2. exergonic 3. anabolic 4. endergonic 5. dehydration synthesis

2. exergonic

In this reaction _______. 1. the chemical energy of the products is greater than that of the reactants 2. entropy has decreased 3. heat has been released to the environment 4. disorder has decreased 5. the kinetic energy of the reactants is less than that of the products

3. heat has been released to the environment

Which of these reactions requires a net input of energy from its surroundings? 1. catabolic 2. exergonic 3. hydrolysis 4. ATP --> ADP + P 5. endergonic

5. endergonic

In this reaction _____. 1. CD is a product 2. AC is a reactant 3. the products have been rearranged to form reactants 4. entropy has decreased 5. the products have less potential energy than the reactants

5. the products have less potential energy than the reactants

Chlorophyll can be found in _____.

A and C

Chloroplast membrane vesicles are equilibrated in a simple solution of pH 5‎ . The solution is then adjusted to pH 8‎ . Which of the following conclusions can be drawn from these experimental conditions?

ATP will not be produced because there is no ADP and inorganic phosphate in the solution.

Identifying the highest energy form of adenosine. Select the highest energy form of adenosine from the following images.

Adenosine triphosphate (ATP) is the high-energy form of adenosine because it contains the most phosphate groups (three).

_____ releases energy that is used to pump hydrogen ions from the stroma into the thylakoid compartment.

B

Energized electrons from ____ enter an electron transport chain and are then used to reduce NADP+.

C

Which of the following statements is most likely to be true in the case of the feedback-regulated enzymatic pathway shown?

P4 binds E1 and deactivates it.

Which term describes ATP production resulting from the capture of light energy by chlorophyll?

Photophosphorylation

According to the chemiosmotic hypothesis, what provides the energy that directly drives ATP synthesis?

Proton Gradient

Which of the following particles can pass through the ATP synthase channel?

Protons

_____ has a longer wavelength than _____.

Red ... Green

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

Substrate

Which of the following would be unlikely to contribute to the substrate specificity of an enzyme?

The enzyme has an allosteric regulatory site.

An enzyme _____.

is an organic catalyst

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

is unchanged

In general, enzymes are what kinds of molecules?

proteins

Enzymes work by _____.

reducing Ea (the energy of activation)

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

γ-phosphate (the terminal phosphate)