Chapter 7: How Cells Release Chemical Energy

Question 1

In order to use the energy stored in sugars, cells must first transfer it to ATP. The energy transfer occurs when bonds of a sugar’s __________ ____________ are broken, driving ATP synthesis.

Answer 1

Carbon backbone

Question 2

What are the two main pathways in which organisms break down sugars to make ATP?

Answer 2

• Aerobic Respiration

* Fermentation

Question 3

• Requires oxygen to break down sugars and make ATP

* Primary pathway of nearly all eukaryotes and some bacteria

Answer 3

Aerobic Respiration

Question 4

• Does not require oxygen to break down sugars and make ATP

* Primary pathway of many bacteria and single-celled protists

Answer 4

Fermentation

Question 5

Aerobic Respiration has three stages that produce a combined total of how many ATP?

Answer 5

36

Question 6

What are the three stages of Aerobic Respiration, where does each stage occur, and how many ATP does each stage produce?

Answer 6

1. Glycolysis
   •occurs in Cytoplasm
   •(net yield: 2 ATP)
2. Krebs Cycle
   •occurs in Mitochondria
   •(net yield: 2 ATP)
3. Electron Transfer Phosphorylation
   • occurs in Mitochondria
   •(net yield: 32 ATP)

Question 7

• Fermentation’s anaerobic pathway has a net yield of _____ ATP to sustain many _______-________ species.
• Like Aerobic Respiration, fermentation begins with ____________ in the cytoplasm.
• Unlike Aerobic Respiration, Fermentation occurs entirely in the ____________, and does not include __________ ____________ _______

Answer 7

• 2
• Single-Celled
• Glycolysis
• Cytoplasm
• Electron Transfer Chains

Question 8

What is the formula for photosynthesis?

Answer 8

6CO2 + 6H2O + light energy
—->
C6H12O6 + 6O2

OR

6 Carbon Dioxide + 6 Water + light energy
—->
Glucose + 6 Oxygen

Question 9

What is the formula for Aerobic Respiration?

Answer 9

C6H12O6 + 6O2
—->
6CO2 + 6H2O

OR

Glucose + 6 Oxygen
—->
6 Carbon Dioxide + 6 Water

Question 10

____________ is defined as a series of reactions that begins the sugar breakdown pathways of both aerobic respiration and fermentation.

Answer 10

Glycolosis

Question 11

This process :

• Occurs in the cytoplasm
• Enters a cell through a glucose transporter
• Enzymes use 2 ATP to convert 1 six-carbon
molecule of sugar (such as glucose) into 2 molecules of pyruvate.

Answer 11

Glycolysis

Question 12

An organic compound with a three-carbon backbone

Answer 12

Pyruvate

Question 13

The direct transfer of a phosphate group from a substrate to ADP is called _________ ______________

Answer 13

substrate phosphorylation

Question 14

WHAT YOU NEED TO KNOW!!!!
(Glycolysis)

Glycolysis starts with ____ six carbon glucose molecule(s)band ends up with ____ three-carbon pyruvate molecule(s)

Answer 14

• 1

* 2

Question 15

WHAT YOU NEED TO KNOW!!!!
(Glycolysis)

Glycolysis requires an initial investment of ____ ATP molecule(s), but produces ____ ATP molecule(s), so the overall ATP net gain for glycolysis is ____ ATP molecule(s).

Answer 15

• 2
• 4
• 2

Question 16

WHAT YOU NEED TO KNOW!!!!
(Glycolysis)

Glycolysis also produces ____ NADPH molecule(s)

Answer 16

• 2

Question 17

WHAT YOU NEED TO KNOW!!!!
(Glycolysis)

Depending on the type of cell or environmental conditions, __________ either enter the second stage of aerobic respiration or are used in other ways, such as ______________.

Answer 17

• Pyruvate

* Fermentation

Question 18

The second stage of aerobic respiration includes what two sets of reactions?

Where does the second stage of aerobic respiration occur?

What is the main purpose of these sets of reactions?

Answer 18

1. Acetyl-CoA Formation
2. Krebs Cycle

• Occur in Mitochondria
• Break down the pyruvate produced during glycolysis

Question 19

During Aerobic Respiration, what are the end products?

What are combined 2nd-stage reactions of aerobic respiration? What is the net yield of 2nd-stage reactions?

Answer 19

Combined 2nd Stage Reactions of Aerobic Respiration (Acetyl-CoA Formation +Krebs Cycle):

• Break down 2 pyruvate into 6 CO2

Net Yield of 2nd Stage Reactions:

•2 ATP
•10 reduced coenzymes
(8 NADH and 2 FADH2)
•Provides electrons to the 3rd stage of aerobic respiration

Question 20

This process is what happens in the transition from glycolysis to the Krebs cycle

Answer 20

Acetyl-CoA Formation

Question 21

How many rounds of the 2nd stage of aerobic respiration (Acetyl-CoA Formation + Krebs Cycle) are required to break down one molecule of glucose?

Answer 21

Two Rounds

Question 22

WHAT YOU NEED TO KNOW!!!!
(2nd Stage of Aerobic Respiration)

The 2nd stage of aerobic respiration occurs inside the _____________ and consists of two sets of reactions: _________ and ___________.

Answer 22

• Mitochondria
• Acetyl-CoA Formation
• Krebs Cycle

Question 23

WHAT YOU NEED TO KNOW!!!!
(2nd Stage of Aerobic Respiration)

During Acetyl-CoA Formation (the transition from __________ to __________), 2 three-carbon _________ molecules produce 2 one-carbon _______ molecules, 2_________ molecules, and 2 two-carbon ________ molecules. The later of which combine with ____________ ___, forming 2 Acetyl-CoA molecules that enter the Krebs cycle

Answer 23

• Glycolysis
• Krebs Cycle
• Pyruvate
• CO2
• NADH
• Carbon Acetyl
• Coenzyme A

Question 24

What is the 3rd stage of Aerobic Respiration?

Answer 24

Electron Transfer Phosphorylation

Question 25

Where does Electron Transfer Phosphorylation occur?

Answer 25

Inner mitochondrial membrane

Question 26

During ELECTRON TRANSFER PHOSPHORYLATION, many ______ are formed. During this stage, coenzymes reduced in the first two stages (NADH and FADH2) deliver ________ and _______ ______ to electron transfer chains. Electrons moving through the chains supply _______, which is used to actively transport hydrogen ions across the _______ __________. As a result, a hydrogen ion __________ is formed driving the formation of ______. This is called _________ Phosphorylation

Answer 26

* ATP * Hydrogen ions * Electrons * Energy * Inner Membrane * Gradient * ATP * Oxidation

Question 27

QUESTION ON EXAM!!! ________ serves as the final electron acceptor when it combines with electrons and hydrogen

Answer 27

Oxygen

Question 28

The end products of ELECTRON TRANSFER PHOSPHORYLATION (Aerobic Respirations Third Stage) are:

Answer 28

* About 32 ATP (yields vary) | * Water as a byproduct

Question 29

During Aerobic Respiration, the overwhelming majority of ATP molecules are made during which stage?

Answer 29

Electron Transfer Phosphorylation

Question 30

Overall, AEROBIC RESPIRATION typically yields _____ ATP

Answer 30

36

Question 31

QUESTION ON EXAM!!!!! At the end of AEROBIC RESPIRATION, the six-carbon ________ molecule is completely broken down into six ______ molecules

Answer 31

* Glucose | * CO2

Question 32

Like Aerobic Respiration, _____________ begins with glycolysis in the cytoplasm

Answer 32

Fermentation

Question 33

In FERMENTATION, the pyruvate is/is not fully broken down into CO2.

Answer 33

Is Not

Question 34

In FERMENTATION, electrons do NOT move through _________ __________ ________, so no additional ATP is formed

Answer 34

Electron Transfer Chains

Question 35

In FERMENTATION, what is regenerated that allows glycolysis to continue?

Answer 35

NAD+

Question 36

What is the net yield of ATP in FERMENTATION?

Answer 36

2ATP

Question 37

What are the 2 FERMENTATION pathways?

Answer 37

1. Alcoholic Fermentation | 2. Lactate Fermentation

Question 38

ANAEROBIC sugar breakdown pathway that PRODUCES ATP, CO2, AND ETHANOL

Answer 38

Alcoholic Fermentation

Question 39

ANAEROBIC sugar breakdown pathway that PRODUCES ATP AND LACTATE

Answer 39

Lactate Fermentation

Question 40

What are the 2 steps of ALCOHOLIC FERMENTATION?

Answer 40

1. Three-Carbon Pyruvate is split into CO2 and Two-Carbon Acetaldehyde 2. Electrons and hydrogen are transferred from NADH to the Acetaldehyde, forming NAD+ and ethanol

Question 41

What are the three steps of ALCOHOLIC FERMENTATION?

Answer 41

1. The electrons and hydrogen ions carried by NADH are transferred directly to pyruvate 2. Pyruvate is converted to three-carbon lactate 3. NADH is converted to NAD+

Question 42

Complex __________, _____, and ________ in food can be converted to molecules that enter aerobic respiration at various reaction steps.

Answer 42

Carbohydrates, fats, and proteins

Question 43

Complex __________ break down into simple sugars (Glycolysis)

Answer 43

Carbohydrates

Question 44

_____ break down into glycerol and fatty acids | Glycolysis and the Krebs Cycle

Answer 44

Fats

Question 45

_______ break down into amino acid subunits (The Krebs Cycle)

Answer 45

Proteins

Question 46

Read over Energy from Fats, Proteins, and Carbohydrates

Answer 46

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