enzymes 2

Multiple Choice

Enzymes are an example of which type of biological molecule?

• carbohydrates

• proteins

• nucleic acid

• fat

Multiple Choice

What is the function of an enzyme?

• To catalyse a reaction, so it takes place more quickly.

• To make a reaction slower, so it can be controlled more easily.

• To alter the taste of a food.

• To provide energy during a reaction.

Multiple Choice

What does the lock and key model represent?

• The way an enzyme works is secret.

• The rate at which a product is created in a catalysed reaction.

• The action of the substrate on the enzyme.

• The way that a particular enzyme fits with a specific substrate.

Multiple Choice

What is the active site of an enzyme?

• It is a group of amino acids lined up in a unique sequence.

• It is the site at which an enzyme attaches to another enzyme.

• It is the site on an enzyme at which substrates bind.

• It is the site at which the enzyme increases its catalytic activity.

Multiple Choice

Which of these is NOT true?

• Enzymes can denature (change shape) when the temperature gets too high.
• Enzymes can only be used once in a chemical reaction. 
• Extreme pH can denature enzymes.
• Enzymes speed up chemical reactions. 

Multiple Choice

Where do substrates bind to an enzyme?

• calcium channels

• active site

• receptor molecules

• voltage-gated channels

Multiple Choice

The ____________________ mechanism describes how each substrate must fit into the enzyme.

• lock and key

• hammer and nail

• jigsaw puzzle

• seesaw

Multiple Choice

Which of the following best explains why enzymes are necessary for reactions in our cells?

• The reactions are too slow to meet the needs of the cell if enzymes are missing.

• Enzymes supply the oxygen necessary for the reactions.

• Enzymes change reactants from solid to liquid during the reactions.

• The reactions take up too much space in the cell if enzymes are missing.

Multiple Choice

Which of these is most likely an enzyme?  

• Sucrose
• Galactose
• Fructose
• Amylase

Multiple Choice

An enzyme speeds up a reaction by

• lowering the activation energy.
• raising the activation energy.
• releasing energy.
• absorbing energy.

Multiple Choice

Letter E...

• active site
• enzyme
• substrate
• products

Multiple Choice

Letter C...

• active site
• enzymes
• substrate
• products

Multiple Choice

Letter B...

• active site
• enzyme
• substrate
• products

Multiple Choice

Letter D...

• active site
• enzyme
• substrate
• products

Multiple Choice

In the diagram, what is letter A? 

• product
• substrate
• enzyme-substrate complex
• active site

Multiple Choice

Each enzyme only has 1 substrate that will fit its active site.  What is this called?

• reusable
• catalyst
• specific
• fragile

Multiple Choice

What is a substance called if it speeds up a chemical reaction?

• reusable
• catalyst
• specific
• fragile

Multiple Choice

What happens when enzymes are heated to a high temperature?

• The enzymes die.

• The shape of the enzyme are changed and it denatures

• The enzymes' amino acid sequence changes.

• The enzymes remain the same

Multiple Choice

Which of the following conclusions can be drawn from this graph?

• The optimum pH of the enzyme is 6.6.
  
• The optimum pH of the enzyme is 5.8
  
• The enzyme’s activity increases as pH increases 5.0 to 9.0
  
• The enzyme’s activity is greater around pH of 8.0 .
  

Multiple Choice

Changes in pH and temperature can ___________________ an enzyme which causes it to lose its shape and affects its function.

• puncture

• denature

• double

• delete

Multiple Choice

What is the optimal pH for this enzyme?

• 6

• 10

• 9

• 7

Multiple Choice

What is the optimal temperature of this enzyme?

• 60

• 40

• 70

• 30

Multiple Choice

What factors affect an enzyme's reaction rate?

• temperature 
• pH
• substrate concentration
• all of these

Multiple Choice

At high temperatures enzyme activity declines because of:

• Denaturation
• Decreased Kinetic Motion
• Increased H-Bonding
• Dissociation of Ionic Compounds

Multiple Choice

Which organ of the body has enzymes with very low optimun pH

• Pancreas

• Small intestine

• Liver

• Stomach

Multiple Choice

An enzyme and its substrate bind together because they have ...

• the same shape

• complementary shapes

• opposite shapes

• different shapes

Multiple Choice

Which enzyme breaks down protein?

• Amylase

• Catalase

• Lipase

• Protease

Multiple Choice

Which reaction is catalysed by lipase?

• Lipids => Glycerol

• Lipids => Amino Acids & Glycerol

• Lipids => Fatty Acids

• Lipids => Fatty Acids & Glycerol

Multiple Choice

The diagram shows an experiment. What is in the water after 15 minutes?

• Amino Acids

• Fatty Acids

• Glucose

• Glycerol

Multiple Choice

Which of these are digested by protease?

• A

• B

• C

• D

Multiple Choice

Which statement is correct?

• Enzymes only breakdown large molecules into smaller molecules.

• Enzymes increase the number of collisions between molecules.

• Enzymes lower the activation energy needed to start a reaction.

• Enzymes provide the activation energy needed to start a reaction.