Enzymes + Metabolism 2023 Flashcards
The _____ activity of all living organisms is controlled by the use of ________.
Cellular, enzymes
An ________ is a special type of biological molecule that usually speeds up a ________ _____ without being consumed or changing the _______ of the reaction.
Enzyme, chemical reaction, products
The enzyme _______ speeds up the ________ of the lipid triglycerides. Sucrase speeds up the hydrolysis of ______ into glucose and ______.
Lipase, hydrolysis, sucrose, fructose
Another term that is used to describe an enzyme is ______. reactions. Each enzyme has a unique ______________ shape, and this shape determines which reaction it _______.
Catalyst, three-dimensional, catalyzes.
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
Reactant, substrate, barrier, faster
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 ______.
Substrates, unchanged, metabolism, catalase.
The _____ _____ is usually a pocket or groove that forms when the newly synthesized ______ folds into its correct three-dimensional shape (_______ structure).
Active site, enzyme, tertiary
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 _______.
Flexible, conformation, substrate
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.
Enzyme-substrate-complex, products, substrate, catalyzing
Many enzymes require a ______, which is a non-_______ group that binds very precisely to an enzyme. _______ are often metals, such as _______.
Cofactor, protein, cofactors, [iron, maganese, copper, zinc, etc.].
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 ___________________________.
Coenzymes, water-soluble vitamins, shuttle, nicotinamide adenine dinucleotide
What are conditions that alter an enzyme’s function?
Temperature, pH, salt concentration, etc.
The concentration of both the _____ and the _____ will influence the rate of a catalysis reaction.
Substrate, enzyme
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.
Inhibitors, enzyme, activity, active site, critical sites
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 ______ _________.
Enzyme activity, noncompetitive reversible, allosteric, active site, allosteric, enzyme activity
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.
Scarce, increases, feedback inhibition, cellular resources
What are real-life examples of enzymes?
Lactase, amylase, catalase, etc.
What is phosphorylation?
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.
What is isomerization?
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)
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 ______.
Glucose, two, pyruvate, three, ATP, NAD+, NADH
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.
Pyruvate, glycolysis, matrix, innermost, two, acetyl CoA, CO2, NADH
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.
Acetyl coA, pyruvate oxidation, four, reactions, four, ATP, NADH, FADH2, carbon dioxide.
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 ______.
NADH, FADH2, electrons, electron transport chain, NAD+, FAD, energy, matrix, gradient, ATP synthase, electron transport chain, electrons, water
Glycolysis can take place without ______ in a process called _________. The other three stages of cellular respiration—_______, __________, _______ require oxygen in order to occur.
Oxygen, fermentation, pyruvate oxidation, citric acid cycle, oxidative phosphorylation.
