Enzymes and Cell respiration

respirometer

A device that can be used to measure the rate of exchange of oxygen and carbon dioxide during fermentation is called a

one type of substrate.

A given enzyme works on

increase the amount of reaction.

An increase in enzyme or substrate concentration will

the reaction rate increases similarly.

As the concentration of an enzyme increases for a given substrate, the rate of the reaction decreases to a point. the reaction rate increases similarly. the turnover number decreases at the same rate that the enzyme concentration increases. the reaction stops. there is no change in the reaction.

measuring the formation of oxygen gas.

Catalase activity can be determined by

only A as substrate.

Consider the biochemical pathway below, where A, B, and C are substrates and products and E1 and E2 are the enzymes that catalyze the reactions. Enzyme 1 (E1) can utilize

by measuring how much of the substrate is consumed by measuring how much of the product is produced

Enzyme activity can be determined in the following ways: by measuring how much of the enzyme is consumed by measuring how much of the substrate is consumed by measuring how much of the product is produced determining when the amount of substrate is equal to the amount of product by measuring the ratio of enzyme to substrate concentration

at specific pH and temperature ranges.

Enzyme function is optimum

Substrates, products

Enzymes act on _______ to generate ________. Substrates, products Products, substrates Products, catabolites Glucose, anabolites

proteins

Enzymes are nucleic acids. proteins. lipids. carbohydrates. steroids.

They are proteins. They can bind with substrate. They act as catalysts.

Enzymes have which of the following characteristics? (check all that apply) They are proteins. They can bind with substrate. They act as catalysts. They are used up during the reaction. They are inorganic molecules.

at 37°C.

Enzymes in human cells tend to perform best when the person has a fever. at 60°C. at 37°C. at 98°C. at 22°C.

lowering activation energy.

Enzymes speed up reactions by

many times

How often can a catalase molecule be used to hydrolyze hydrogen peroxide? once never twice many times

The molecules of substrate were all bound to enzyme. As a reaction rate increases, eventually all available substrate molecules will be bound to enzymes, or all available enzymes will be bound to substrate. The reaction will be substrate-limited or enzyme-limited. When all available molecules of either enzyme or substrate are bound, saturation occurs, and at this point the reaction rate will level off. To keep increasing the reaction rate, the levels of available substrate or enzyme must increase. In the above example, additional enzyme was added, so substrate must have been the limiting factor.

Imagine that you are observing an enzyme-catalyzed reaction in lab. Every time you add more enzyme, the reaction rate increases proportionally until the reaction rate suddenly levels off. No other chemicals were added, and no modifications were made in the experimental setting. Why do you think the reaction rate stopped increasing? The enzymes were denatured. The molecules of enzyme were used up in the reaction. The molecules of substrate noncompetitively inhibited the enzyme. The molecules of product competitively inhibited the substrate. The molecules of substrate were all bound to enzyme.

a mixture of hydrogen peroxide and water.

In a catalase controlled experiment, the negative control can be shown by a mixture of hydrogen peroxide and catalase. hydrogen peroxide only. catalase only. a mixture of water and catalase. a mixture of hydrogen peroxide and water.

a mixture of water and catalase. a mixture of hydrogen peroxide and water.

In a catalase controlled experiment, the specificity of catalase can be shown by comparing a mixture of hydrogen peroxide and catalase. a mixture of water and catalase. a mixture of hydrogen peroxide and water. catalase alone. hydrogen peroxide alone.

an inhibitor

In an enzyme controlled reaction, a substrate is the same as none of these options are correct an inhibitor enzyme reactant product

measuring the air bubble produced inside respirometer

In the fermentation experiment by yeast, one can tell which sugar was fermented more effectively by_____? measuring the amount of sugar consumed by yeast measuring the color of the solution after incubation measuring the air bubble produced inside respirometer measuring the amount of ATP produced

False

Polysaccharides are easier to ferment as compared to monossacharides True False

FALSE The active site is part of enzyme structure.

The active site is located on the substrate. True False

is where it works best.

The optimum condition for an enzyme

reduced the energy of activation and increase the rate of a reaction.

The primary function of an enzyme or any biological catalyst is to reduce the energy of activation of a reaction. reduced the energy of activation and increase the rate of a reaction. increase the rate of a reaction and change the direction of a reaction. increase the rate of a reaction. change the direction of a reaction.

carbon dioxide (CO2) and ethanol (C2H6O) + 2ATP

The products of fermentation by yeast are:_____ carbon dioxide (CO2) and ethanol (C2H6O) + 2ATP carbon dioxide (CO2) and water (H2O) + 2ATP carbon dioxide (6CO2), ethanol (6H2O) and 36 ATP. carbon dioxide (6CO2), water (6H2O) and 36 ATP.

True

The shape of an enzyme determines its function. True False

ENZYME

The use of the suffix "ase" on a word denotes a(n)

Absence of oxygen

Under what environmental conditions do yeast carry out fermentation?

produce ATP

What is the purpose of both cellular respiration and fermentation? produce ATP produce glucose form oxygen ferment oxygen

substrate

Which of the following binds to the active site of an enzyme? none of the above substrate product any other enzyme water

The substrate binds to the enzyme with low specificity.

Which of the following statements about enzymes is FALSE? The enzyme undergoes a conformational change that brings substrates closer together in an induced fit. The active site of the enzyme is where the chemical reaction takes place. The substrate binds to the enzyme with low specificity. The optimal activity of an enzyme occurs over a narrow temperature range. The optimal activity of an enzyme occurs within a narrow pH range.

glucose

Which of the following substrates is fermented most easily by yeast?

True

Yeast can produce 2 ATP per molecule of glucose when using fermentation. True False

all of the choices are correct

Yeast tubes with sugar and respirometers need to be incubated at 37°C because:______________ 37°C is the optimal temperature necessary for yeast to grow lower temperatures may cause the metabolism to slow down to undetectable levels higher temperatures may kill the yeast all of the choices are correct

TEMPERATURE AND PH

_________ can change the active site of an enzyme and alter its function.

glucose - monosaccaride sucrose - diascarraride

match each sugar with the type of sugar they are 1. glucose 2. sucrose