Chapter 5 Microbial Metabolism

Which of the following is primarily involved in catabolic reactions? A. NAP+ B. NADP+ C. both NAP+ and NADP+ D. neither NAP+ or NADP+

A. NAP+

As catalysts, enzymes typically ______ chemical reactions. A. accelerate B. decelerate

A. accelerate

The protein portion of an enzyme is called ____. A. apoenzyme B. cofactor

A. apoenzyme

Another term for an anabolic reaction is _____ reactions. A. biosynthetic B. degradative

A. biosynthetic

Enzymes that release energy are _____. A. catabolic B. anabolic

A. catabolic

When cells break down sugars into carbon dioxide and water, this is a ____ reaction. A. catabolic B. anabolic

A. catabolic

Catabolic reactions are ____. A. exergonic B. endergonic

A. exergonic

Feedback inhibition generally acts on the ___ enzyme in the metabolic pathway. A. first B. second C. third D. fourth

A. first

ONly when the concentration of substrate is _____ can the maximum rate of enzyme catalyzing be attained. A. high B. low

A. high

______ inhibitors bind to an allosteric site on the enzyme. A. noncompetitive B. competitive

A. noncompetitive

Unstable bonds in ATp allow energy to be released _____. A. quicker B. slower

A. quicker

Allosteric inhibition change the shape of the active site. A. true B. false

A. true

Catabolic reactions provide building blocks for anabolicreactions, and they furnish the energy needed to drive anabolic reactions. A. true B. false

A. true

Coenzymes assist the enzyme by either donation or removing atoms from the substrate. A. true B. false

A. true

Denaturation involves breaking hydrogen and other noncovalent bonds. A. true B. false

A. true

Each enzyme catalyzes only one reaction. A. true B. false

A. true

In living systems, enzymes increase the reaction rate without increasing the temperature. A. true B. false

A. true

NAD+ and NADP+ are two of the most important coenzymes in cellular metabolism. A. true B. false

A. true

The active site and substrate change shape somewhat to make them fit together. A. true B. false

A. true

The collision of atoms, ions, and molecules results in the energy transferred breaking and forming bonds. A. true B. false

A. true

The collision theory basis is that all atoms, ions, and molecules are continuously moving and colliding. A. true B. false

A. true

The ezyme will orient the substrate into a position that increases the probabibilty of a reaction. A. true B. false

A. true

Write the formula for the catabolic process of ATP synthesis.

ADP+Pi(inorganic phosphate) + energy--->ATP

What molecule makes the coupling of catabolic and anabolic reactions possible?

ATP

Write the formula for the anabolic process of ATP breakdown.

ATP--->ADP + Pi(inorganic phosphate) +energy

The minimum collision energy required for a chemical reaction to occur.

Activation Energy

The turnover number is generally between_____. A. 1 and 1,000 B. 1 and 10,000 C. 1 and 100,000 D. 1 and 500,000

B. 1 and 10,000

Which of the following is primarily involved in anabolic reactions? A. NAP+ B. NADP+ C. both are involed D. neither are involved

B. NADP+

Which vitamin functions in the metabolism of pyruvic acid? A. Riboflavin B. Thiamine C. Niacin D. Vitamin B6

B. Thiamine

Enzymes requiring energy are _____. A. catabolic B. anabolic

B. anabolic

The formation of proteins from amino acids, nucleic acids, and nucleotides is an example of an/a _____ reaction. A. catabolic B. anabolic

B. anabolic

Unstable bonds in ATp provide the cell with readily available energy for ____ reactions. A. catabolic B. anabolic

B. anabolic

The non protein portion of an enzyme is called _____> A. apoenzyme B. cofactor

B. cofactor

_____ inhibitors fill the active site of the enzyme A. noncompetitive B. competitive

B. competitive

An enzyme-substrate complex ______ the activation energy of the reaction. A. increases B. decreases

B. decreases

Another term for catabolic reactions is _____ reactions. A. biosynthetic B. degradative

B. degradative

Anabolic reactions are ____. A. exergonic B. endergonic

B. endergonic

All of the energy released in catabolic reactions can be used for cellular functions. A. true B. false

B. false

As catalysts, enzymes are nonspecific. A. true B. false

B. false

The chemical composition of a cell is always the same, never changing. A. true B. false

B. false

Apoenzymes are _____ by themselves. A. active B. inactive

B. inactive

Does a competitive inhibitor undergo a reaction to form products? A. yes B. no

B. no

The shape and chemical structure of a competitive inhibitor is ______ to that of the normal substrate. A. different B. similar

B. similar

ATP has ____ bonds. A. stable B. unstable

B. unstable

Which of the following can denature an enzyme? A. heavy metal ions B. concentrated bases C. UV radiation D. concentrated acids E. all of the above F. none of the above

E. all of the above

Consume more energy than produced

Endergonic

A temporary union of an enzyme and its substrate is called ?

Enzyme-substrate complex

In living cells, ______ serve as biological catalysts.

Enzymes

Produce more energy than consumed

Exergonic

Which control mechanism stops the cell from making more of a substance than it needs and therby wasting chemical resources.

Feedback Inhibition (end-product inhibition)

Part of the energy released in catabolic reactions is lost to the environment as _____.

Heat

Together, the apoenzymes and cofactor form a _______.

Holoenzyme ( whole, active enzyme)

The H+ and OH- of acids and bases compete with the ____ and ____ bonds in an enzyme

Hydrogen and Ionic

Catabolism is generally ____ reactions

Hydrolytic

Reactions which use water and in which chemical bonds are broken

Hydrolytic Reactions

A sequence of enzymatically catalyzed reactions occurring in a cell

Metabolic Pathway

The sum of all the chemical reactions that occur in a living cell

Metabolism

ATP consists of one ____, one _____, and three _____

One ribose, one adenine, and three phosphate groups

Enzymes in the oxidoreductase class that add molecular oxygen are called _____.

Oxidases

___ is the removal of electrons from an atom or molecule.

Oxidation

The frequency of collisions containing sufficient energy to bring about a reaction is called the _______ rate.

Reaction Rate

An enzyme consisting of RNA that specifically acts on strands of RNA to remove introns and splice together the remaining exons is called _____.

Ribozyme

The condition in which the active site on an enzyme is occupied by the substrate at all times is called ___.

Saturation

Under conditions of high substrate concentration, the enzyme is said to be in ______.

Saturation

The specificity of enzymes is made possible by their ______.

Structures

Each enzyme acts on a sepcific substance called the enzyme's ______.

Substrate

The energy from catabolic reactions is used to combine 1.____ and an 2._____ to form 3.____.

1. ADP 2. Pi(inorganic phosphate) 3. ATP

When the terminal phosphate group is split from 1. ____ and 2. ____ is formed.

1. ATP 2. ADP

Metabolic pathways are determined by their 1. _____, which are in turn determined by the cell's 2. _____.

1. Enzymes 2. Genetic makeup

What are the 6 classes of enzymes?

1. Oxidoreductase 2. Transferase 3.Hydrolase 4. Lyase 5.Isomerase 6.Ligase

Sucrose is the 1. _____ of the enzyme 2. _____ which catalyzes the hydrolysis of sucrose to 3. _____ and 4. _____.

1. Substrate 2. Sucrase 3. Glucose 4. Fuctose

List three ways to increase the reaction rate of a substance.

1. increase temperature 2. increase pressure 3. make reactants more concentrated

If molecule A loses an electron, it has gone through 1. ____; if molecule B gains an electron it has gone through 2, _______.

1. oxidation 2. reduction

Each time a substance is oxidized, another substance is 1. _____ and is known as the 2. ______.

1.Reduced 2. Redox Reaction ( oxidation-reduction)

ATP 1. _____ energy from catabolic reactions and 2. _____ for anabolic reactions.

1.Stores 2. Releases

_____ inhibition is the process in which the inhibitor binds to an allosteric site on the enzyme.

Allosteric inhibition

The building of complex organic molecules from simpler ones.

Anabolism

What is the average temperature for most disease-producing bacteria in the human body? A. 25-30*C B. 30-35*C C. 35-40*C D. 40-45*C

C. 35-40*C

The turnover number can be as high as _______. A. 50,000 B. 10,000 C. 500,000 D. 100,000

C. 500,000

Which of the following acts as an electron carrier? A. NAP+ B. NADP+ C. both NAP+ and NADP+ D. neither NAP+ or NADP+

C. both NAP+ and NADP+

Which of the following contains derivatives of vitamin B Niacin? A. NAP+ B. NADP+ C. both NAP+ and NADP+ D. neither NAP+ or NADP+

C. both NAP+ and NADP+

Why is the ability of enzymes accelerating reactions without increasing the temperature vital to living systems? A. Increasing the temperature would cause too many collisions B. Increasing the temperature would destroy the cell's plasma membrane C. increasing the temperature would destroy the cell's proteins.

C. increasing the temperature would destroy the cell's proteins

What is the first to occur in an enzyme action? A. enzyme-substrate complex forms B. substrate molecule is transformed C. the active site on enzyme is contacted by the substrate D.transformed substrate molecules are released

C. the active site on the enzyme is contacted by the substrate

Which of the following is NOT a factor in determining whether a collision will cause a chemical reaction? A. the velocity of the colliding particles B. their level of energy C. their size D. their chemical configurations

C. their size

Many coenzymes are derived from _____. A. proteins B. carbohydrates C. vitamins D. sugars

C. vitamins

Decomposition reaction; the breakdown of complex organic compounds into simpler ones

Catabolism

Substances that speed up a chemical reaction without being permanently altered themselves is a _____.

Catalyst

If the cofactor is an organic molecule it is called _____.

Coenzyme

______ activate apoenzymes.

Cofactors

The principle(theory) that chemical reactions occur because energy is gained as particles collide.

Collision Theory

Enzyme inhibitors are classigied as either ____ or _____ inhibitors.

Competitive or Noncompetitive

Enzymes can catalyze reactions up to _____ times higher than those of comparable reactions without enzymes. A. 1 million B. 1 billion C. 10 million D. 10 billion

D. 10 billion

Which of the following plays a significant role in the synthesis and breakdown of fats and in the Krebs cycle? A. NAP+ B. NADP+ C. FMN D. CoA E. FAD

D. CoA (coenzyme A)

Ribozymes _____. A. have active sites that bind to ubstrates B. function as catalysts C. are not used up in chemical reactions D. all of the above E. none of the above

D. all of the above

Anabolic reactions involve ______ reactions.

Dehydration Synthesis

Reactions that release water

Dehydration Synthesis

Enzymes in the oxidoreductase class that remove hydrogen from a substrate are called ____.

Dehydrogenases

A change in the molecular structure of a protein is called ____.

Denaturation

Each enzyme has a ____ dimensional shape with a specific surface configuration as a result of their primary, secondary, and tertiary structures

Three dimensional

The maximum number of substrate molecules acted on per enzyme molecule per second.

Turnover number