C1.1 Enzymes and Metabolism- IB BIO

Fill in the Blank

___________ is defined as the ability to do work.

Multiple Choice

What is the sum of all the chemical reactions in an organism called?

• Catabolism

• Anabolism

• Metabolism

• Energy

Multiple Choice

___________ is when smaller molecules are combined to produce larger molecules and store energy (Ex: Photosynthesis).

• Catabolism

• Anabolism

• Metabolism

• Energy

Multiple Choice

Which of the following statements best represents the first law of thermodynamics?

• As an athlete runs, they are converting chemical energy to mechanical muscle movement and thermal energy.

• Diesel engines function by converting fuel energy into work and heat

• A bear can convert chemical energy from its food, like salmon, into kinetic energy by walking up the stream

• As temperature approaches absolute zero, the entropy of the system approaches a constant value

Multiple Choice

___________ is when larger molecules are broken down into smaller molecules and release energy (Ex: Cellular Respiration).

• Catabolism

• Anabolism

• Metabolism

• Energy

Multiple Choice

_____________ reactions release energy while  _____________ reactions  absorb energy.

• Endergonic; Exergonic

• Exergonic ; Endergonic

• Kinetic; Potential

• Potential; Kinetic

Multiple Choice

True or False: The First Law of Thermodynamics states that energy cannot be created or destroyed, but it can be transferred or transformed into another type of energy.

• True

• False

Fill in the Blank

Think: In cells, what form is the energy (or fuel) to function and perform necessary processes?

Multiple Choice

REVIEW: How does ATP release energy?

• By breaking the 2nd and 3rd phosphate group

• By joining a 4th phosphate group

• By joining another molecule, causing it to break

• By spontaneously releasing energy

Multiple Choice

What is the act of ADDING a high-energized phosphate group to another molecule in order to transfer energy?

• ATP

• Chemiosmosis

• Photosynthesis

• Phosphorylation

Open Ended

How do enzymes speed up reactions?

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Multiple Choice

What is found at Label A?

• Enzyme

• Substrate

• Enzyme-Substrate Complex

• Active Site

• Products

Multiple Choice

What is found at Label B?

• Enzyme

• Substrate

• Enzyme-Substrate Complex

• Active Site

• Products

Multiple Choice

What is found at Label C?

• Enzyme

• Substrate

• Enzyme-Substrate Complex

• Active Site

• Products

Multiple Choice

What is found at Label D?

• Enzyme

• Substrate

• Enzyme-Substrate Complex

• Active Site

• Products

Multiple Choice

What is found at Label E?

• Enzyme

• Substrate

• Enzyme-Substrate Complex

• Active Site

• Products

Multiple Choice

Is this a CATABOLIC or ANABOLIC enzyme reaction?

• Catabolic Reaction

• Anabolic Reaction

Multiple Choice

True or False: Enzymes are naturally occurring biological catalysts that speed up the rate of reactions by RAISING the activation energy.

• True

• False

Open Ended

Explain enzyme–substrate specificity. (3 marks)

Question Marking Scheme (3 marks)

a. enzymes are proteins with specific 3-D geometry/shape 
b. enzymes with active site that binds with the substrate/reactants 

c. active site shape only allows it to bind with specific substrates «with complementary shapes» 

d. when enzyme-substrate complex formed allows reaction to occur 

e. products are released and enzyme returns to original shape and can be reused
OR
denaturing changes shape «of active site» so changes ability to bind with substrate

Open Ended

Some people are lactose intolerant, meaning they cannot digest lactose. Lactose is a carbohydrate found in dairy products. There is a wide range of onset for this condition; sometimes babies are born with lactose intolerance and sometimes people develop lactose intolerance in adulthood. If a baby is born with lactose intolerance it is due to mutations in the LCT gene. The LCT gene provides the instructions for making the enzyme that can digest lactose, known as lactase. The chemical reaction can be seen below.

b) Identify the monomers of Lactose.

Open Ended

Some people are lactose intolerant, meaning they cannot digest lactose. Lactose is a carbohydrate found in dairy products. There is a wide range of onset for this condition; sometimes babies are born with lactose intolerance and sometimes people develop lactose intolerance in adulthood. If a baby is born with lactose intolerance it is due to mutations in the LCT gene. The LCT gene provides the instructions for making the enzyme that can digest lactose, known as lactase. The chemical reaction can be seen below.

b) Explain how the mutation in the LCT gene would result in lactose intolerance.

Multiple Choice

Which statement applies to the tertiary structure of enzymes?

• Tertiary structure is the sequence of amino acids in an enzyme.

• Some enzymes do not have a tertiary structure.

• An example of tertiary structure in an enzyme is the alpha helix.

• A change in the tertiary structure of an enzyme may result in a change in the structure of the active site

Fill in the Blank

___________________ is when the active site changes shape due to environmental factors like temperature, pH, or salinity, and causes the enzyme to no longer function due to the change in shape.

Fill in the Blank

The diagrams represent the structure of a protein before and after it has become denatured.

(a) State how many different types of amino acid there are.

Open Ended

The diagrams represent the structure of a protein before and after it has become denatured.

(b) Outline one cause of denaturation in proteins.

Open Ended

The diagrams represent the structure of a protein before and after it has become denatured.

(c) Explain how denaturation affects the activity of an enzyme.

Multiple Choice

Which curve shows the concentration of product during the course of an enzyme-catalysed reaction?

• Curve A

• Curve B

• Curve C

• Curve D

Draw

Sketch a graph to show the effect of temperature on the activity of enzymes.

Don't forget labels on the axes!

Graph Drawing Markscheme

a. axes labelled correctly: x-axis as temperature AND y-axis as rate of reaction/enzyme activity 
b. correct shape of graph: increases gradually to max and then decreases more rapidly

Fall should be at least twice as steep as rise.

Let's Review what we've learned!

Multiple Choice

An experiment was conducted examining the effects of catalase on hydrogen peroxide. The catalase used in the experiment was extracted from potatoes. Varying concentrations of catalase were made, and filter paper disks were cut out and soaked in the various catalase concentrations. After soaking in the catalase, the filter paper disks were dabbed on a paper towel and then placed in a 3% hydrogen peroxide solution. As catalase reacted with the hydrogen peroxide, bubbles formed on the surface of the filter paper disks and they floated to the surface. Examine the data in the chart to the right. Which statement below best explains why the filter paper disks floated to the surface?

• The higher the concentration of catalase the more heat there was being generated by the reactions.

• The increased catalase concentrations altered the pH of the surrounding solution.

• Increasing enzyme concentration will speed up the reaction.

• The formation of bubbles increased the entropy of the solution thereby increasing the activity of the enzyme.

Multiple Choice

The researcher wanted to continue the experiment and include higher concentrations of catalase (0-400 units/mL). Which graph below best predicts the results of the experiment if it were to be continued?

Multiple Choice

Which of the following statements is NOT true in regard to environmental impacts on enzyme function?

• A change in pH can cause denaturation

• After a certain temperature enzyme activity begins to decrease.

• A change in salinity can cause enzymes to become inactive

• A decrease in substrate concentration can increase enzyme activity

Open Ended

Lipase is an enzyme found in the stomach acid to help break down lipids. Lipase is typically found in a pH of 2. Amylase is an enzyme found in the saliva whose job is to start digesting sugars as soon as it enters a person's mouth. Because amylase is found in the saliva, it is typically found in a pH of 7.

What would happen is amylase were to be added to the stomach acid with a pH of 2, where lipase is normally found and functions normally?

Open Ended

Peroxidase enzyme (HRP) in horseradish (Armoracia rusticana) plants is used to break down hydrogen peroxide into water and oxygen. The extracted enzyme also has industrial uses when immobilized in ferrosoferric oxide (Fe₃O₄) and embedded in a polymer matrix. The graph shows the relative activity of HRP in both its free and immobilized forms at different temperatures. The results are a mean of three trials.

QUESTION: State the effect that immobilizing the enzyme had on the relative activity of the enzyme.

Question Marksheme from IB

QUESTION: State the effect that immobilizing the enzyme had on the relative activity of the enzyme.


ANSWER: (1 mark) activity of the enzyme is higher than normal enzymes (at temperatures over 30 °C)

Open Ended

Peroxidase enzyme (HRP) in horseradish (Armoracia rusticana) plants is used to break down hydrogen peroxide into water and oxygen. The extracted enzyme also has industrial uses when immobilized in ferrosoferric oxide (Fe₃O₄) and embedded in a polymer matrix. The graph shows the relative activity of HRP in both its free and immobilized forms at different temperatures. The results are a mean of three trials.

QUESTION: Identify one variable that should be kept constant while measuring enzyme activity at all temperatures.

Question Marksheme from IB

QUESTION: Identify one variable that should be kept constant while measuring enzyme activity at all temperatures.

ANSWER: (1 mark) pH/concentration of enzyme/concentration of substrate

• Do not accept temperature

• Do not accept “amount”