8

Question 1

How do cells obtain energy?

Answer 1

Non-photosynthetic organisms obtain energy by ingesting organic molecules that were created by photosynthetic organisms. These molecules were created by converting the energy from sunlight into the chemical energy found in the bonds of organic molecules.

Question 2

Oxidation

Answer 2

a process in which an electron is removed from a molecule. This often results in the breaking of a chemical bond.

Question 3

Reduction

Answer 3

a process in which an electron is gained by a molecule. This often results in the formation of a chemical bond.

Question 4

Cells ___ ____ _______ to obtain energy from its bonds through _______ _________.

Answer 4

Cells break down glucose to obtain energy from its bonds through cellular respiration.

Question 5

Cellular respiration 3 stages

Answer 5

Glycolysis
Kreb Cycle
Electron Transport

Question 6

The complete breakdown of glucose is the opposite of photosynthesis: (equation)

Answer 6

C6H12O6 + 6O2 → 6CO2 + 6H2O + chemical energy (ATP)

Question 7

_____ (C6H12O6) is _____ during ________ and __ is reduced

Answer 7

glucose (C6H12O6) is oxidized during cellular respiration and O2 is reduced.

Question 8

The bonds of _____ are broken as ______ are stripped away (______), and new bonds are created as __ is converted into ___ (______).

Answer 8

The bonds of glucose are broken as electrons are stripped away (oxidation), and new bonds are created as O2 is converted into H2O (reduction).

Question 9

________ is the multi-step process in which a molecule of _______ is broken down into _ ______ molecules. As bonds are broken, the energy released is used to create a ___ __ _ ___ (_ ATP is produced, _ ATP is used during the chemical reactions) AND electrons that were removed from the molecule are transferred to _____ creating _____.

Answer 9

Glycolysis is the multi-step process in which a molecule of glucose is broken down into 2 pyruvate molecules. As bonds are broken, the energy released is used to create a net of 2 ATP (4 ATP is produced, 2 ATP is used during the chemical reactions) AND electrons that were removed from the molecule are transferred to 2NAD+ creating 2NADH.

Question 10

Glycolysis occurs in the ________ __ ___ ____

Glycolysis occurs in both the ________ and _______ of __

Answer 10

Glycolysis occurs in the cytoplasm of the cell

Glycolysis occurs in both the presence and absence of O2

Question 11

The entire process of ________ requires __ steps, each of which is mediated by an ______. The steps can be broken down into _ steps that “________” glucose and _ steps that _______ energy from glucose

Answer 11

The entire process of glycolysis requires 10 steps, each of which is mediated by an enzyme. The steps can be broken down into 5 steps that “activate” glucose and 5 steps that extract energy from glucose

Question 12

Glucose activation
1) _________ transferred from ___ to _______
2) ___________
3) A second _______ transferred from ___
4) A _-______ _________ splits into two different _-______ ___________
5) One of the _-______ __________ is converted into the other type, so there are ___ _________ of ____

Answer 12

1) Phosphate transferred from ATP to glucose
2) Rearrangement
3) A second phosphate transferred from ATP
4) A 6-carbon intermediate splits into two different 3-carbon intermediates
5) One of the 3-carbon intermediates is converted into the other type, so there are two molecules of PGAL

Question 13

Energy extraction
6) ________ and ____________
7) _______-level _____________ yields ___
8) ___________
9) _______ of ___
10) ________-level ____________ yields ___ and ___ molecules of _______ ___ _______

Answer 13

6) Oxidation and phosphorylation
7) Substrate-level phosphorylation yields ATP
8) Rearrangement
9) Removal of H2O
10) Substrate-level phosphorylation yields ATP and two molecules of pyruvate per glucose

Question 14

__________ are the site of _______ _______. A single muscle or nerve cell may contain as many as _________ ________.

Answer 14

Mitochondria are the site of aerobic respiration. A single muscle or nerve cell may contain as many as 10,000 mitochondria.

Question 15

After the _ ______ molecules have been produced in _______ they are moved into the _____ of the _______.

Answer 15

After the 2 pyruvate molecules have been produced in glycolysis they are moved into the matrix of the mitochondria.

Question 16

A mitochondria consists of an _____ _______ and a highly _____ _____ ________. ______ are _____ that greatly increase the ______ _____ of the inner _______. The _____ is the _____ _______ within the _____ _______.

Answer 16

A mitochondria consists of an outer membrane and a highly folded inner membrane. Cristae are folds that greatly increase the surface area of the inner membrane. The matrix is the space enclosed within the inner membrane.

Question 17

Cellular Respiration occurs when __ is present following glycolysis.

Answer 17

Cellular Respiration occurs when O2 is present following glycolysis.

Question 18

Cellular respiration breaks ______ molecules down into ___, produces ____, and converts _____ and _____ into _____ and ______ molecules respectively.

Answer 18

This process breaks pyruvate molecules down into CO2, produces 2ATP, and converts 8NAD+ and 2FAD+ into 8NADH and 2FADH2 molecules respectively.

Question 19

Cellular respiration occurs in the __________

Answer 19

Cellular respiration occurs in the Mitochondria

Question 20

Cellular respiration 3 stages

Answer 20

Kreb Cycle
Electron Transport
Oxidative Phosphorylation

Question 21

Aerobic respiration begins with the _______ of _______ to _____ ___.
This process generates ____ and releases ___ as a biproduct.

Answer 21

Aerobic respiration begins with the oxidation of pyruvate to Acetyl CoA.
This process generates NADH and releases CO2 as a biproduct.

Question 22

The _____ cycle (also known as the Citric Acid cycle or TCA cycle) completes the _______ of the ____-___ producing ____, _____,___ and ___.
Each glucose molecule produces _ _______. Therefore, _ ____-___ molecules enter the cycle for each glucose.

Answer 22

The Krebs cycle (also known as the Citric Acid cycle or TCA cycle) completes the oxidation of the acetyl-coA producing NADH, FADH2, ATP and CO2.
Each glucose molecule produces 2 pyruvates. Therefore, 2 acetyl-coA molecules enter the cycle for each glucose.

Question 23

The series of reactions are utilized to remove ______ and _____ ____ (H+) from ____-___.
An _______ is removed in each reaction that is coupled with ____ or ___.

Answer 23

The series of reactions shown in the previous slide are utilized to remove electrons and hydrogen ions (H+) from acetyl-coA.
An electron is removed in each reaction that is coupled with NAD+ or FAD.

Question 24

_______ (which carry energy) are picked up by ________ which, in turn, are _______. These ________ may be donated to other compounds.

Answer 24

Electrons (which carry energy) are picked up by coenzymes which, in turn, are reduced. These electrons may be donated to other compounds.

Question 25

NAD+
NAD+ —> ____ (reduced form of NAD+)

Answer 25

NAD+
NAD+ —> NADH (reduced form of NAD+)

Question 26

FAD
FAD —> _____ (reduced form of FAD)

Answer 26

FAD
FAD —> FADH2 (reduced form of FAD)

Question 27

An _______ _______ ____ in the _____ mitochondrial membrane _______ the ______ ______ of the electron carriers (NADH and FADH2) to ___.

Answer 27

An electron transport chain in the inner mitochondrial membrane transfers the potential energy of the electron carriers (NADH and FADH2) to ATP.

Question 28

_____ ________ and ______ ________ produces __% of the total ___ obtained from a single ______ molecule.

Answer 28

Electron transport and oxidative phosphorylation produces 90% of the total ATP obtained from a single glucose molecule.

Question 29

__ serves as the _______ _______ acceptor of the ______ ______ _____. The __ molecules are reduced to form ___.

Answer 29

O2 serves as the terminal electron acceptor of the electron transport chain. The O2 molecules are reduced to form H2O.

Question 30

Electron transport begins as _______ are _______ from ____ and _____ to ______ embedded in the _____ membrane of the __________.

Answer 30

Electron transport begins as electrons are released from NADH and FADH2 to proteins embedded in the inner membrane of the mitochondria.

Question 31

As the _______ are passed from ______ to ______, a current is generated that activates _____ (H+) pumps. The _____ pumps ______ _______ from the _____ of the ________ to the _________ _________.

Answer 31

As the electrons are passed from protein to protein, a current is generated that activates proton (H+) pumps. The proton pumps deliver protons from the matrix of the mitochondria to the intermembrane compartment.

Question 32

A ________ ________ is produced as ______ (H+) are pumped into the _________ __________ (high _____ concentration in the ___________ ________, low ____ concentration in the ____).

Answer 32

A concentration gradient is produced as protons (H+) are pumped into the intermembrane compartment (high proton concentration in the intermembrane compartment, low proton concentration in the matrix).

Question 33

In short, the purpose of the _______ _______ _____ is to create a ______ _________ _______ inside the _________.

Answer 33

In short, the purpose of the electron transport chain is to create a proton concentration gradient inside the mitochondria.

Question 34

_________ _________ is the process in which ATP is synthesized (ADP+phosphate) using the energy of the proton gradient.

Answer 34

Oxidative phosphorylation is the process in which ATP is synthesized (ADP+phosphate) using the energy of the proton gradient.

Question 35

In Oxidative phosphorylation, channels (ATP synthase) _____ and allow ______ to flow back into the _____ of the __________. The ______ _____ of the moving _____ is used by the channels to bond ___ with ______ to create ___.

Answer 35

In this process, channels (ATP synthase) open and allow protons to flow back into the matrix of the mitochondria. The kinetic energy of the moving protons is used by the channels to bond ADP with phosphate to create ATP.

Question 36

In theory, the ATP yield from electron transport is _ ATPs per ____ and _ ATPs per _____.

Answer 36

In theory, the ATP yield from electron transport is 3 ATPs per NADH and 2 ATPs per FADH2.

Question 37

__ NADHs are produced between ________ and the _____ _____. This yields __ ATP.

Answer 37

10 NADHs are produced between glycolysis and the Krebs cycle. This yields 30 ATP.

Question 38

_ FADH2 are produced in the _____ _____. This yields _ ATP.

Answer 38

2 FADH2 are produced in the Krebs cycle. This yields 4 ATP.

Question 39

A net of _ ATPs are produced directly during _______ and the _____ ____

Answer 39

A net of 4 ATPs are produced directly during glycolysis and the Krebs cycle

Question 40

a single glucose molecule may yield __ ATP from ______ followed by _______ ______.

Answer 40

a single glucose molecule may yield 38 ATP from glycolysis followed by aerobic respiration.

Question 41

When an organism depletes its immediate carbohydrate supplies, cells may use _____ ____ as an energy source. First, ______ (NH3) is stripped from the amino acid and excreted. The remainder of each molecule is converted into ______, ____-___, or an _______ of the Krebs cycle depending upon the amino acid.

Answer 41

When an organism depletes its immediate carbohydrate supplies, cells may use amino acids as an energy source. First, ammonia (NH3) is stripped from the amino acid and excreted. The remainder of each molecule is converted into pyruvate, acetyl-coA, or an intermediate of the Krebs cycle depending upon the amino acid.

Question 42

____ may be used as an energy source in 2 ways. The ______ is removed and converted into ______. The ____ _____ enter the mitochondria and are cut into ____-___. A single fat molecule can produce at least __ acetyl-coA (therefore __ NADH, therefore ___ ATP).

Answer 42

Fats may be used as an energy source in 2 ways. The glycerol is removed and converted into pyruvate. The fatty acids enter the mitochondria and are cut into acetyl-coA. A single fat molecule can produce at least 30 acetyl-coA (therefore 60 NADH, therefore 180 ATP).

Question 43

Anaerobic respiration is essentially the same as aerobic respiration, except that an ______ molecule other than __ is the electron acceptor at the end of the electron transport chain. Electron acceptors include: NO3- (_____), SO4-2 (____), and CO2.

Answer 43

Anaerobic respiration is essentially the same as aerobic respiration, except that an inorganic molecule other than O2 is the electron acceptor at the end of the electron transport chain. Electron acceptors include: NO3- (nitrate), SO4-2 (sulfate), and CO2.

Question 44

Anaerobic respiration always produces ____ ATPs than aerobic respiration (the number varies).

Answer 44

Anaerobic respiration always produces fewer ATPs than aerobic respiration (the number varies).

Question 45

When O2 is not available to undergo cellular respiration, pyruvate will be metabolized using fermentation reactions:
_____ ____ Fermentation
_____ Fermentation

Answer 45

When O2 is not available to undergo cellular respiration, pyruvate will be metabolized using fermentation reactions:
Lactic Acid Fermentation
Alcohol Fermentation

Question 46

electrons from ____ are used to reduce ______. This regenerates ____ and allows for ______ to continue. This process is very inefficient and results in very ___ ATP production. In general, it is performed by __________ that live in ____-rich environments were food is relatively ______.

Answer 46

electrons from NADH are used to reduce pyruvate. This regenerates NAD+ and allows for glycolysis to continue. This process is very inefficient and results in very low ATP production. In general, it is performed by microorganisms that live in sugar-rich environments were food is relatively unlimited.

Question 47

The electrons that were transferred to ____ (creating NADH) in ________ are donated back to _____ creating lactic acid.

Answer 47

The electrons that were transferred to NAD+ (creating NADH) in glycolysis are donated back to pyruvate creating lactic acid.

Question 48

Microorganisms, such as yeast, undergo alcohol fermentation when __ is not available.

Answer 48

Microorganisms, such as yeast, undergo alcohol fermentation when O2 is not available.

Question 49

As with lactic acid fermentation, __ and electrons from NADH are used to convert pyruvate into _____ and ___.

Answer 49

As with lactic acid fermentation, H+ and electrons from NADH are used to convert pyruvate into ethanol and CO2.