Enzymes + Metabolism 2023 Flashcards

1
Q

The _____ activity of all living organisms is controlled by the use of ________.

A

Cellular, enzymes

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2
Q

An ________ is a special type of biological molecule that usually speeds up a ________ _____ without being consumed or changing the _______ of the reaction.

A

Enzyme, chemical reaction, products

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3
Q

The enzyme _______ speeds up the ________ of the lipid triglycerides. Sucrase speeds up the hydrolysis of ______ into glucose and ______.

A

Lipase, hydrolysis, sucrose, fructose

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4
Q

Another term that is used to describe an enzyme is ______. reactions. Each enzyme has a unique ______________ shape, and this shape determines which reaction it _______.

A

Catalyst, three-dimensional, catalyzes.

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5
Q

Enzymes bind a specific ________, called a ______; in doing so, they lower the energy ______ so that the reaction proceeds at a _______ rate than it would without the enzymes

A

Reactant, substrate, barrier, faster

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6
Q

In a reaction that uses an enzyme, the enzyme combines briefly with the ______ and, after releasing the products, is _______. For example, hydrogen peroxide is a toxic chemical that occurs in cells as a by-product of ________. To prevent cell damage, hydrogen peroxide is broken down by the enzyme ______.

A

Substrates, unchanged, metabolism, catalase.

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7
Q

The _____ _____ is usually a pocket or groove that forms when the newly synthesized ______ folds into its correct three-dimensional shape (_______ structure).

A

Active site, enzyme, tertiary

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8
Q

Research by enzymologists shows that enzymes are not rigid objects, like locks, but are ________. Just prior to substrate binding, the enzyme changes its shape, or what is called its _______, so that the active site becomes even more precise in its ability to bind to its _______.

A

Flexible, conformation, substrate

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9
Q

An enzyme binds to one or more substrates, forming an ___________________. The enzyme then converts the substrate(s) into one or more ________. Since enzymes remain unchanged after a reaction, enzyme molecules can rapidly bind to other ________ molecules, ________ the same reaction repeatedly.

A

Enzyme-substrate-complex, products, substrate, catalyzing

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10
Q

Many enzymes require a ______, which is a non-_______ group that binds very precisely to an enzyme. _______ are often metals, such as _______.

A

Cofactor, protein, cofactors, [iron, maganese, copper, zinc, etc.].

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11
Q

Organic cofactors called _______ play similar roles and are often derived from ________ _____. Many co enzymes ______ molecules from one enzyme to another. One of the most important co enzymes is ___________________________.

A

Coenzymes, water-soluble vitamins, shuttle, nicotinamide adenine dinucleotide

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12
Q

What are conditions that alter an enzyme’s function?

A

Temperature, pH, salt concentration, etc.

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13
Q

The concentration of both the _____ and the _____ will influence the rate of a catalysis reaction.

A

Substrate, enzyme

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14
Q

Enzyme ______ lower the rate at which an enzyme catalyzes a reaction. They are molecules that bind to an ______ and decrease its _______. Some of them work by binding to the ___________ of an enzyme, while other inhibitors bind to ___________ located elsewhere in the structure of the enzyme.

A

Inhibitors, enzyme, activity, active site, critical sites

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15
Q

Molecules that naturally regulate __________ ______ in a cell often behave somewhat like a ____________ __________ inhibitor. These regulatory molecules bind to an enzyme on a site that is not its active site, called the _________ site, and cause a change in the shape of the enzyme, thus affecting the ___________. This type of regulation, in which a protein’s function at one site is affected by a molecule binding to a separate site, is called _________ regulation. It may either inhibit or stimulate ______ _________.

A

Enzyme activity, noncompetitive reversible, allosteric, active site, allosteric, enzyme activity

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16
Q

If the product is _______, the inhibition is reduced, and the rate of the reaction _________. Regulation of this type, in which the product of a reaction acts as a regulator of the reaction, is called ________ __________. It prevents ________ _________from being wasted in the synthesis of molecules.

A

Scarce, increases, feedback inhibition, cellular resources

17
Q

What are real-life examples of enzymes?

A

Lactase, amylase, catalase, etc.

18
Q

What is phosphorylation?

A

Phosphorylation is the addition or transfer of a phosphate group to a molecule by an enzyme called protein kinase. Generally, a phosphate group comes from ATP or from ADP.

19
Q

What is isomerization?

A

the chemical process by which a compound is transformed into any of its isomeric forms, (forms with the same chemical composition but with different structure or configuration)

20
Q

In glycolysis, ______ undergoes a series of chemical transformations. In the end, it gets converted into _____ molecules of ______, a ______-carbon organic molecule. In these reactions, _____ is made, and _____ is converted to ______.

A

Glucose, two, pyruvate, three, ATP, NAD+, NADH

21
Q

In pyruvate oxidation, each __________ from _________ goes into the mitochondrial ______—the _______________ compartment of mitochondria. There, it’s converted into a ____-carbon molecule bound to coenzyme A, known as __________. __________ is released and ________ is generated.

A

Pyruvate, glycolysis, matrix, innermost, two, acetyl CoA, CO2, NADH

22
Q

In the citric acid cycle, The ________ made in ______ combines with a _____-carbon molecule and goes through a cycle of __________, ultimately regenerating the _____-carbon starting molecule. Three molecules, _______________ are produced, and ______________ is released.

A

Acetyl coA, pyruvate oxidation, four, reactions, four, ATP, NADH, FADH2, carbon dioxide.

23
Q

In oxidative phosphorylation, The ____ and ______ made in other steps deposit their ______ in the __________________, turning back into their “empty” forms, _______ and ______. As electrons move down the chain, ______ is released and used to pump Protons flow out of the _______, forming a ________. _______ Proton flow back into the matrix through an enzyme called ___________, making ATP. At the end of the _____________, oxygen accepts _______ and takes up protons to form ______.

A

NADH, FADH2, electrons, electron transport chain, NAD+, FAD, energy, matrix, gradient, ATP synthase, electron transport chain, electrons, water

24
Q

Glycolysis can take place without ______ in a process called _________. The other three stages of cellular respiration—_______, __________, _______ require oxygen in order to occur.

A

Oxygen, fermentation, pyruvate oxidation, citric acid cycle, oxidative phosphorylation.

25
Q

What is needed for glycolysis to occur? What is the output?

A

Input is 1 glucose, 2NAD+, 2 ATP, 2ADP, 2P2. Output is 2 pyruvate, 4 ATP.

26
Q

What is oxidation (reduction)? What is dehydration?

A

Oxidation is the LOSS of ELECTRONS by molecules. These electrons are picked up by NAD+ or FAD. This reaction will also reverse to transfer the electrons elsewhere. Dehydration is the loss of water.

27
Q

What is dephosphorylation? What is decarboxylation?

A

Dephosphorylation is the removal of a phosphate group from a molecule by a phosphatase. Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2).

28
Q

What is the most important enzyme for regulation of glycolysis? What does it do? What are two other molecules that have similar functions?

A

Phosphofructokinase is the most important. It speeds up or slows down glycolysis in response to the body’s needs. Hexokinase and pyruvate kinase are similar.

29
Q

What organ is glycolysis essential to? What is the reverse of glycolysis?

A

The brain. Gluconeogenesis.

30
Q

About 65-70% of ATP is synthesized in the ___________. Besides ATP, it also synthesizes ________________________.

A

Citric acid cycle. Amino acids, glucose, heme, etc.

31
Q

What is the purpose of the electron transport chain? What does it produce?

A

The ETC occurs across the inter-mitochondrial membrane. A chemical gradient is formed across the membrane to drive formation of ATP, produced by the ATP synthase enzyme. ATP and water are produced.

32
Q

_______ and _____ transport electrons to the _____________________. This is a series of _______ embedded in the ____________ membrane. As electrons pass along it, an _____________ gradient of protons (______ ions) is established. The flow of ____ ions back through ______ ________ drives the formation of ________. ATP is made of ____ and ___.

A

NADH, FADH2, electron transport chain, proteins, inter-mitochondial, electrochemical, hydrogen, hydrogen, ATP synthase, ATP, ADP, P(i).