Unit 3 Cell Energy Test

Enzymes ___________________ activation energy to speed up chemical reactions.

• increase

• decrease

What is the relationship between an enzymes active site and its substrate?

• The active site has the right polarity to interact with the substrate.

• The active site is hydrophobic and interacts with other hydrophobic amino acids on the substrate

• The active site has a specific shape that fits the shape of the substrate

• The active site uses energy to form covalent bonds with the substrate

How does a competitive inhibitor affect an enzymes function?

• It binds to an allosteric site that alters the shape of the enzyme

• It changes the polarity of the enzyme, decreasing the rate of reaction

• It denatures the enzyme which increases the activation energy for the reaction.

• It binds to the active site, preventing the enzyme from catalyzing the reaction

Which of these factors can affect the initial rate of an enzyme reaction?

• Enzyme concentration

• Substrate concentration

• Temperature

• pH

• All of the above

What effect does high temperature have on most enzymes reaction rates?

• High temperatures will speed up the enzyme's reaction rate

• High temperatures will stabilize the enzyme's reaction rate

• High temperatures will decrease enzyme reaction rates due to denaturation

• High temperatures do not affect enzyme reaction rates

How does initial substrate concentration affect enzyme reaction rates?

• High concentration of substrates will inhibit enzyme reaction rates

• Low concentration of substrate will increase enzyme reaction rates

• High initial concentrations of substrate will increase the enzyme reaction rate

• Enzyme reaction rates are independent of substrate concentration

In scientific experiments what is a control?

• The variable that is manipulated by the researcher

• A test that does not have the independent variable, to show a baseline with no reaction

• A test where the researcher does not know which sample contains which variable

• The variable that changes based on the experimental conditions

What is chemiosmosis?

• The diffusion of electrons through the electron transport chain

• The breakdown of a glucose molecule

• The diffusion of protons down their concentration gradient

• The active transport of NADH into the mitochondria

Tags

NGSS.HS-LS1-7

Why is chemiosmosis important to cellular respiration?

• It provides the energy needed to catabolize glucose

• It is the force that powers ATP synthase

• It provides the energy needed to breakdown pyruvate into carbon dioxide

• It generates the electrons needed for the electron transport chain

Tags

NGSS.HS-LS2-3

Why is the hydrolysis of ATP important to a cells function?

• It provides a source of phosphate for the cell.

• It releases energy that can be used to power cellular processes

• It absorbs excess hydrogen ions in the cell to regulate the internal pH

• It acts as a catalyst for chemical reactions in the cell.