Chp. 5 A

Question 1

What is metabolism?

Answer 1

The breakdown and buildup of material within a cell

Question 2

What are the two types of chemical reaction monomers? Explain them

Answer 2

• Catabolic monomers: break down macromolecules into simple parts, releasing energy in the process
• Anabolic monomers: build up macromolecules by combining simpler molecules, using energy in the process

Question 3

Anything that ends in ase is a _______

Anything that ends in ose is a ________

Answer 3

• Enzyme
• Sugar

Question 4

Is cellular respiration catabolic or anabolic?

Answer 4

Catabolic

Question 5

What is the collision theory?

Answer 5

Chemical reactions happen when atoms, ions, and molecules collide

Question 6

What is the starting material and end material known as?

Answer 6

Substrate of reactant
Product of a reactant

Question 7

Define activation energy

Answer 7

The collision energy required for a chemical reaction to occur

Question 8

Define reaction rate

Answer 8

How fast it would take for collisions to occur to bring about a reaction

Question 9

Enzymes _____ the activation energy and ______ the rate of reaction. They are ________

Answer 9

• Lower
• Increase
• Catalysts

Question 10

What are the two parts of an enzyme?

Answer 10

• Active site
• Allosteric site

Question 11

What is the purpose of the allosteric site?

Answer 11

Change the shape of the active site

Question 12

What is an induced fit?

Answer 12

When the substrate moves into an active site and the site tightens around the substrate to keep it inside

Question 13

The protein portion of an enzyme is the ______

Answer 13

Apoenzyme

Question 14

The nonprotein portion of an enzyme is the ______

Answer 14

Cofactor

Question 15

What are some examples of cofactors?

Answer 15

• Vitamins
• Minerals
• Metals

Question 16

What are coenzymes?

Answer 16

Organic cofactors

Question 17

An apoenzyme PLUS a cofactor is a _______

Answer 17

Holoenzyme

Question 18

What does the cofactor do?

Answer 18

Helps the substrate fit into the apoenzyme

Question 19

What factors will denature enzymes?

Answer 19

• High temperature
• High salt concentration
• High OR low pH

Question 20

What factors will slow down an enzyme but not denature it?

Answer 20

• Low temperature
• Very slight change in pH

Question 21

What factors will affect the rate of reaction?

Answer 21

• Substrate concentration (the more substrate, the longer the reaction takes)
• More enzyme: less time reaction takes place

Question 22

What is the difference between exoenzymes and endoenzymes?

Answer 22

Exoenzymes are released outside of the cell and are not active inside of the cell whereas endoenzymes function and are active inside of the cell

Question 23

What is a Turnover number?

What is the turnover number of enzymes?

Answer 23

• The number of substrate molecules an enzyme converts to a product per second
• 1- 10,000

Question 24

Anabolic reactions that form covalent bonds between smaller substrate molecules are known as __________

Answer 24

Synthesis or condensation reactions

Question 25

Catabolic reactions that break down substrates into smaller molecules and require water input to break bonds is known as ________

Answer 25

Hydrolysis

Question 26

What is a competitive inhibitor and noncompetitive inhibitor?

Answer 26

Competitive inhibitor: competes with a substrate for the active site Noncompetitive inhibitor: enzymes are regulated by the binding of molecules other than the substrate away from the active site

Question 27

Explain competitive inhibition

Answer 27

- Both molecules compete for the active site - Reaction proceeds - Reaction is blocked because competitive inhibitor is incapable of becoming a product

Question 28

Explain noncompetitive (allosteric) inhibition

Answer 28

- Enzyme substrate reaction proceeds, products are released - A product of the enzyme reaction binds to the regulatory site and causes a change in the shape of the active site - Substrate cannot fit, enzyme action is blocked

Question 29

Where does Glycolysis take place in prokaryotes and eukaryotes?

Answer 29

Both take place in the cytoplasm

Question 30

Where does the Krebs cycle take place in prokaryotes and eukaryotes?

Answer 30

P: Cytoplasm E: Matrix of mitochondria

Question 31

Where does the electron transport chain take place in prokaryotes and eukaryotes?

Answer 31

P: Cell/ plasma membrane E: Inner mitochondrial membrane

Question 32

Do prokaryotes require oxygen for the following: - Glycolysis - Krebs cycle - Electron transport chain

Answer 32

- NO - YES - YES

Question 33

Do eukaryotes require oxygen for the following: - Glycolysis - Krebs cycle - Electron transport chain

Answer 33

- NO - YES - YES

Question 34

NAD+ and FADH carry what?

Answer 34

Electrons

Question 35

What is the net output of Glycolysis?

Answer 35

2 ATP 2 NADH 2 Pyruvic acids

Question 36

What is the net output of the Krebs cycle?

Answer 36

4 CO2 6 NADH 2 ATP 2 FADH2

Question 37

What is the net output of Electron transport and Oxidative Phosphorylation?

Answer 37

34 ATP 6 H2O

Question 38

TRUE OR FALSE: Enzymes are nonspecific to a substrate

Answer 38

FALSE: Enzymes are specific to one substrate

Question 39

Explain Glycolysis

Answer 39

Glucose (6c) is oxidized and split into 2 molecules of pyruvic acid (3C). NADH is generated

Question 40

Explain the Krebs cycle

Answer 40

- Each pyruvic acid from glycolysis is oxidized and decarboxylation (loss of CO2) occurs - The two carbon compound attaches to coenzyme A, forming Acetyl CoA and NADH - Oxidation of acetyl CoA produces NADH, FADH2, and ATP, and liberates CO2 as waste

Question 41

Explain chemiosmosis

Answer 41

- Electrons from NADH pass down the ETC while protons are pumped across the membrane - It establishes proton gradient - Protons in higher concentration on one side of the membrane diffuse through ATP synthase - Movement causes phosphorylation of ADP to form ATP

Question 42

Explain the electron transport chain. What is the final electron acceptor?

Answer 42

ETC is 4 protein complexes embedded in inner mitochondrial membrane. It accepts electrons from NADH and FADH. Generates energy (ATP) through oxidative phosphorylation Final electron acceptor: O2

Question 43

Explain oxidative phosphorylation in ETC

Answer 43

The electron transport chain is composed of 4 protein complexes embedded in the inner mitochondrial membrane. - High-energy electrons are donated by NADH and FADH₂, which are produced earlier in cellular respiration - These electrons pass through the complexes, and as they move through the chain, their energy is used to pump protons (H⁺ ions) from the mitochondrial matrix into the intermembrane space, creating a proton gradient. ## Footnote - Oxygen (O₂) is the final electron acceptor at the end of the chain. It combines with electrons and protons to form water (H₂O). This is why oxygen is essential for oxidative phosphorylation.