Biology Metabolism

Question 1

___ is the sum of all chemical reactions that occur in the body

Answer 1

Metabolism

Question 2

Metabolism can be divided into ___ reactions, which break down chemicals and release energy, and anabolic reactions

Answer 2

catabolic

Question 3

___ respiration describes the biochemical conversion of chemical energy stored in molecular bonds into usable energy (ATP), a catabolic process

Answer 3

cellular

Question 4

Aerobic (cellular) respiration occurs in the presence of ___, while anaerobic (cellular) respiration occurs in the absence of ___

Answer 4

oxygen

Question 5

External respiration refers to the inhaling and exhaling of air into and out of the lungs as well as the ___ of gas between the alveoli and the blood

Answer 5

exchange

Question 6

Internal respiration refers to exchange of gas between ___ cells and the extracellular fluid

Answer 6

individual

Question 7

If energy is released during a reaction, then the products must have less ___ energy than the reactants

Answer 7

potential

Question 8

The primary difference between metabolism and combustion is that cellular respiration releases this energy in a series of smaller steps, thereby allowing the cell to capture the energy for use rather than the ___ being released to the environment as heat as seen in combustion

Answer 8

energy

Question 9

___ literally means “sugar breaking” and is a series of reactions that lead to the oxidative breakdown of glucose into two molecules of pyruvate, the production of ATP, and the reduction of NAD+ into NADH

Answer 9

Glycolysis

Question 10

In a redox reaction there is always a compound that is oxidized and one that is ___

Answer 10

reduced

Question 11

In the case of glycolysis, ___ is oxidized and NAD+ is reduced

Answer 11

glucose

Question 12

The entirety of glycolysis occurs in the ___ and, therefore , can be completed by both eukaryotic and prokaryotic cells

Answer 12

cytoplasm

Question 13

The ___ (steps 1 - 3) gets its name from the fact that two ATP’s are used to add two phosphate groups to glucose, producing fructose 1,6-biphosphate (6 carbon)

Answer 13

energy investment stage

Question 14

The second stage of glycolysis (step 4), ___, splits fructose 1,6-biphosphate into glyceraldehyde 3-phosphate (PGAL) and dihydroxyacetone phosphate (DHAP), each being a 3 carbon compound with an added phosphate group

Answer 14

cleavage

Question 15

___ is then isomerized to form a second PGAL

Answer 15

DHAP

Question 16

The third stage of glycolysis (steps 5-9), ___, results in the production of ATP

Answer 16

energy payout

Question 17

Energy payout occurs ___ per glucose molecule because there are two PGAL’s

Answer 17

twice

Question 18

In this series of steps, PGAL is ___ converted to pyruvate resulting in the reduction of NAD+ to NADH (catalyzed by dehydrogenase) and the production of two ATPs (catayzed by kinases)

Answer 18

converted

Question 19

For glycolysis, one molecule of glucose yields two molecules of ___ which are obtained

Answer 19

pyruvate

Question 20

During this sequence of reactions, two ATP are used and four ___ are generated

Answer 20

ATP

Question 21

For glycolysis, there is a net production of two ATP per ___ molecule

Answer 21

glucose

Question 22

Substrate level phosphorylation takes place in glycolysis because ATP synthesis is directly coupled with ___ of glucose without participation of an intermediate molecule such as NADH or FADH2

Answer 22

oxidation

Question 23

Oxidative phosphorylation does require an intermediate ___ carrier such as NADH or FADH2

Answer 23

electron

Question 24

After glycolysis, energy remains in pyruvate and pyruvate ___ can take place in aerobic or anaerobic conditions

Answer 24

degradation

Question 25

NAD+ must be regenerated for glycolysis to continue in the ___ of O2

Answer 25

absence

Question 26

In anaerobic respiration, fermentation does not produce any ATP itself; therefore, glucose metabolized in the ___ pathway only produces the two ATP through glycolysis

Answer 26

anaerobic

Question 27

Alcohol fermentation coverts the pyruvate produced in ___ to ethanol

Answer 27

glycolysis

Question 28

In lactic acid fermentation, the NAD+ used in step 5 of glycolysis is regenerated when ___ is reduced

Answer 28

pyruvate

Question 29

Whereas anaerobic respiration yields only 2 ATP per molecule of ___ from glycolysis, aerobic respiration can yield 36-38 ATP

Answer 29

glucose

Question 30

The pyruvate produced from glycolysis is transported through both mitochondrial membranes into the mitochondrial matrix where it undergoes ___ decarboxylation to produce acetyl-CoA

Answer 30

pyruvate

Question 31

In aerobic respiration, acetyl-CoA undergoes a cycle of reactions known as the citric acid cycle (sometimes called the TCA or Krebs cycle) producing electron carriers (NADH and FADH2) and regenerating ___, allowing the cycle to happen continuously

Answer 31

oxaloacatate

Question 32

In aerobic respiration when electron carriers NADH and FADH2 are made these elelctron carriers power protons (H+) against their concentration gradient into the ___ space

Answer 32

intermembrane

Question 33

When electron carriers take part in the Electron Transport Chain (ETC) this method of ATP production is termed ___ phosphorylation

Answer 33

oxidative

Question 34

Prokaryotes do not have mitochondria but aerobic bacteria are still able to partake in aerobic respiration, but the citric acid cycle occurs in the ___ and the electron transport chain is located on the bacterial membrane itself

Answer 34

cytosol

Question 35

The pyruvate formed during glycolysis is transported from the cytoplasm into the mitochondrial matrix where it is decarboxylated (i.e., it loses a CO2), and the acetyl group that remains is transferred to ___ A to form acetyl-CoA

Answer 35

coenzyme

Question 36

During pyruvate decarboxylation NAD+ is ___ to NADH

Answer 36

reduced

Question 37

The cycle begins when the two-carbon acetyl group from acetyl-CoA combines with oxaloacetate, a four-carbon molecule, to form the six-___ citrate

Answer 37

carbon

Question 38

Through a series of reactions, two CO2 are released and oxaloacetate, a four-carbon molecule is regenerated for use in ___ turn of the cycle

Answer 38

another

Question 39

For each turn of the citric acid cycle, one ATP is produced by substrate-level ___ via a GTP intermediate

Answer 39

phosphorylation

Question 40

During the citric acid cycle, electrons are transferred to NAD+ and FAD, generating three ___ and one FADH2

Answer 40

NADH

Question 41

These reduction reactions in the TCA are coupled with the ___ of carbon, producing two CO2

Answer 41

oxidation

Question 42

For each molecule of glucose in the TCA, two pyruvate are decarboxylated and ___ into the citric acid cycle

Answer 42

channeled

Question 43

At this stage of TCA cycle, two of each type of molecular product at this stage are created for each ___ molecule

Answer 43

glucose

Question 44

The electron transport chain (ETC) is a complex ___ mechanism located on the inside of the inner mitochondrial membrane

Answer 44

carrier

Question 45

During oxidative phosphorylation, ATP is produced when high-energy potential electrons are transferred from NADH and FADH2 to oxygen by a series of carrier molecules located in the inner ___ membrane

Answer 45

mitochondrial

Question 46

As electrons are transferred in the ETC, ___ energy is released which is then used to form ATP

Answer 46

free

Question 47

Most molecules of the ETC are ___, electron carriers that resemble hemoglobin in the structure of their active site

Answer 47

cytochrome

Question 48

The last carrier of the ETC passes its electron to the ___ electron acceptor, O2

Answer 48

final

Question 49

O2 picks up a pair of hydrogen ions from the surrounding medium, forming ___

Answer 49

water

Question 50

The coupling agent for the TCA and ETC is a proton gradient across the inner mitochondrial membrane ___ by the ETC

Answer 50

maintained

Question 51

As NADH and FADH2 pass their electrons to the ETC, H+ ions are pumped out of the matrix, across the inner mitochondrial membrane, and into the ___ space at each of the ETC protein complexes

Answer 51

intermembrane

Question 52

The continuous translocation of H+ creates a positively charged, acidic environment in the ___ space

Answer 52

intermembrane

Question 53

In order to pass through the membrane (which is impermeable to ions), H+ must flow through specialized channels provided by enzyme complexes called ___ synthases, enough energy is released to allow for the phosphorylation of ADP to ATP

Answer 53

ATP

Question 54

___ phosphorylation is the coupling of the oxidation of NADH and FADH2 with the phosphorylation of ADP

Answer 54

oxidative

Question 55

Fat molecules are stored in adipose tissue in the ___ of triglycerides

Answer 55

form

Question 56

When needed, they are hydrolyzed by lipases to fatty acids and glycerol and are carried by the ___ to other tissues for oxidation

Answer 56

blood

Question 57

With each round of beta-oxidation of a ___ fatty acid, one NADH and one FADH2 are generated

Answer 57

saturated

Question 58

The process of photosynthesis can be divided into light reactions and dark reactions which although ___ with the light reactions do not require sunlight

Answer 58

coupled

Question 59

When light strikes a P700 molecule, it excites electrons, these ___ energy electrons can flow along two pathways giving cyclic electron flow or non cyclic electron flow

Answer 59

high

Question 60

During photosynthesis, the series of redox reactions are harnessed using an electron transport chain, a proton gradient, and ATP ___ to produce ATP from ADP and Pi in a process called cyclic photophosphorylation

Answer 60

synthase

Question 61

P700 then P680 are used to undergo the electron transport chain upon a photon ___ electrons

Answer 61

exciting

Question 62

The dark reactions use the ATP and NADPH produced by the light reactions to reduce ___ to carbohydrates

Answer 62

CO2

Question 63

Although these reactions do not directly require light, they will only occur during the day, when the light ___ are replenishing the supply of ATP and NADPH

Answer 63

reactions

Question 64

CO2 is the source of ___ in the Calvin Cycle

Answer 64

carbohydrate

Question 65

The product of the ___cycle is the three carbon sugar phosphoglyceraldehyde (PGAL)

Answer 65

Calvin

Question 66

Calvin cycle is similar to the Krebs cycle in reverse: (1) carbon dioxide is fed into the cycle; in the Krebs cycle it was produced and released; (2) reducing power is utilized during the cycle (NADPH); in the Krebs cycle NADH was removed; (3) ___ is used in the cycle (conversion of ATP to ADP); in the Krebs cycle, energy was produced when ATP was formed from ADP and inorganic phosphate

Answer 66

energy