Download Cellular Respirationn Review Answers

Section 2.2 Questions
(Pages 115–116)
Understanding Concepts
1. The raw materials required for the cell to produce one
molecule of ATP via substrate-level phosphorylation are ADP,
Pi (or a phosphate-containing intermediate from glucose), and
a substrate enzyme.
2. (a) Glycolysis occurs in the cytoplasm of eukaryotic
organisms.
(b) Glycolysis refers to the breaking of the glucose molecule
into two pyruvate molecules.
3. One molecule of glucose stores more potential energy than
one molecule of pyruvate because in glycolysis, some
potential energy of the original glucose molecule is shared
between 2 NADH and 2 ATP molecules. Some potential
energy is also dissipated as heat.
4. (a) The final products of glycolysis are 2 pyruvate, 4 ATP,
2 NADH, 2 H+, and 2 ADP.
(b) The two products of glycolysis that enter the mitochondria
are pyruvate and NADH.
5. Substrate-level phosphorylation generates ATP directly
from an enzyme-catalyzed reaction, whereas oxidative
phosphorylation generates ATP indirectly by the chemiosmotic
potential created by oxidative phosphorylation. The
process is oxidative because it involves several sequential
redox reactions, with oxygen being the final electron acceptor.
It is more complex than substrate-level phosphorylation, and
it produces far more ATP for every glucose molecule
processed.
6. Adenosine diphosphate (ADP) has two inorganic phosphate
groups attached to an adenosine molecule, whereas adenosine
triphosphate (ATP) has three inorganic phosphate groups
attached to an adenosine molecule. The ATP molecule has 31
kJ/mol more potential energy than ADP.
7. Heart muscle cells have the most mitochondria, as they
require the most energy to contract approximately 70 times
per minute. Nerve cells have the second most mitochondria, as
they need to maintain the membrane potential necessary to
conduct a nerve impulse. Skin cells are next, as their functions
require little energy, followed by fat cells, which do
nothing but accumulate fat.
8. Mitochondrial membranes perform several vital roles in energy metabolism. The outer membrane of the mitochondria
acts as a cell membrane and houses transport proteins that allow substances in and out of the mitochondria. For instance,
the outer membrane houses transport proteins, which move the two pyruvate molecules formed during glycolysis from the
cytoplasm into the mitochondria, where they undergo pyruvate oxidation before entering the Krebs cycle. The inner
membrane of mitochondria serves several functions. It divides the mitochondrion into two compartments: the matrix and
the intermembrane space. Both of these areas play important roles in energy metabolism. For instance, the matrix is where
most of the Krebs cycle reactions take place and the intermembrane space is where protons are pumped as they are
produced by the electron transport chain. These protons are used to create the electrochemical gradient that stores free
energy, which is necessary to create ATP. The inner membrane of a mitochondria also houses the numerous proteins and cofactors required
ultimately to generate ATP. NADH hydrogenase, cytochrome b- c1 complex, cytochrome oxidase
complex, and ATP synthase are all found in the inner mitochondrial membrane.
9. (a) Enzymes are biological catalysts. They speed up
reactions without being consumed in the process. Every
reaction in cellular respiration is catalyzed by a specific
enzyme, as every enzyme has a unique substrate-binding site.
The enzymes exhibit specificity to ensure that the correct
reaction in the process is being carried out at the correct
time. The enzymes ensure that the reactions are occurring in
the correct order and that they are occurring at the correct
speed.
(b) If an organism lacked the first enzyme, in glycolysis,
hexokinase, cellular respiration would not occur.
10. The function of NAD+ and FAD in cellular respiration is to
act as coenzymes that harvest energy from the reactions of
glycolysis, pyruvate oxidation, and the Krebs cycle and carry
it to power ATP synthesis by oxidative phosphorylation.
NAD+ is used to shuttle electrons to the first component of
the electron transport chain. During oxidative phosphorylation,
NAD+ removes two hydrogen atoms from a part of the original
glucose molecule. Two electrons and one proton attach to
NAD+, reducing it to NADH (NAD+ is the oxidized form of
NADH). This reduction occurs during glycolysis, pyruvate
oxidation, and the Krebs cycle. FAD functions in a similar
manner to NAD+. FAD is reduced by two hydrogen atoms
from the original glucose molecule to FADH2. This is done
during the Krebs cycle. These reductions are energy
harvesting and will transfer their free energy to ATP
molecules. Reduced NAD+ and FAD move free energy from one
place to another and from one molecule to another.
11. The final products of cellular respiration are 6 CO2, 6
H2O, and 36 ATP.
12. Glycolysis is not considered a highly effective energyharnessing mechanism, because it only transfers about 2.1% of
the free energy available in one mol of glucose into ATP. Most
of the energy is still trapped in two pyruvate molecules and
two NADH molecules. Aerobic respiration further processes
the pyruvate and NADH during pyruvate oxidation, the
Krebs cycle, chemiosmosis, and electron transport. During
pyruvate oxidation, the pyruvate and NADH are transformed
into two molecules each of acetyl-CoA, hydrogen, carbon
dioxide, and NADH. Acetyl-CoA enters the Krebs cycle and
increases ATP production. By the end of the Krebs cycle, the
entire original glucose molecule is consumed. It has been
transformed into six CO2 molecules, which are released as
waste, and energy, which is stored as four ATP molecules and
12 reduced coenzymes (NADH and FADH2). Most of the free
energy stored in NADH and FADH2 will be transformed to
ATP in the final stage of aerobic respiration, chemiosmosis,
and electron transport. By the end of aerobic respiration, all
the energy available in glucose has been harnessed.
13. After glycolysis, pyruvate oxidation, and the Krebs cycle,
the rest of the energy not captured in the form of ATP is
stored as FADH2 and NADH. Two NADH are produced via
glycolysis, two are produced during pyruvate oxidation, and six
are produced during the Krebs cycle. Two FADH2 are produced
during the Krebs cycle. The free energy stored in these
molecules is released during chemiosmosis and electron
transport.
14. (a) Hydrogen atoms are the part of the glucose molecule
that provides electrons in cellular respiration.
(b) Electron transport complexes set up a proton gradient by
passing protons from the mitochondrial matrix to the
intermembrane space. NADH gives up the two electrons it
carries to NADH hydrogenase. Electron carriers, ubiquinone
and cytochrome c, shuttle electrons from NADH hydrogenase
to cytochrone b- c1 complex to cytochrome oxidase
complex. Free energy is lost from the electrons during each
step in this process, and this energy is used to pump H+
from the matrix into the intermembrane space. The final step
in the electron transport chain sees oxygen accept two
electrons from cytochrome oxidase complex, and it consumes
protons to form water.
(c) The protons that accumulate in the intermembrane space
create an electrochemical gradient. The gradient has two
components: an electrical one caused by a higher positive
charge in the intermembrane space than in the matrix, and a
chemical gradient created by the higher concentration of
protons in the intermembrane space. The electrochemical
gradient stores free energy, which is referred to as protonmotive force (PMF). The mitochondrial membrane is almost
impermeable to protons, so the protons are forced to pass
through ATP synthase to get back into the mitochondrial
matrix. The PMF forces the protons through ATP synthase,
reducing the energy of the gradient. The energy is used by
the enzyme ATP synthase to create the third phosphate-ester
bond between ADP and inorganic phosphate, creating
ATP.
(d) This process is termed chemiosmosis (oxidative
phosphorylation).
(e) Chemiosmosis was discovered by Peter Mitchell in 1961.
15. (a) An electron carrier is first oxidized and then reduced
by a more electronegative molecule, while a terminal electron
acceptor is only reduced—a terminal electron acceptor is at
the end of an electron transport chain.
(b) The final electron acceptor in aerobic respiration is
oxygen.
16. The overall equation (C6H12O6 + 6O2 6 6CO2 + 6H2O)
for cellular respiration is misleading as it does not include the
numerous enzymes, coenzymes, and intermediate chemicals
involved in the process. It also shows the conversion of
glucose and oxygen to carbon dioxide and water as a simple,
one-step process, where it is actually much more involved
than that.
17. CO2 cannot serve as a source of free energy because the
carbon atoms are fully oxidized; there are no H atoms bonded
to any of the C valence electron positions. Thus, its chemical
potential energy is 0 kJ/mole.
18. (a) Metabolic rate is the amount of energy consumed by an
organism in a period, whereas basal metabolic rate is the
minimum amount of energy an organism must consume just to
stay alive.
(b) A person’s metabolic rate decreases with age because of
reduced growth and development. This occurs via a reduction
in growth hormone, which causes excess energy to be used to
create fat.
Applying Inquiry Skills
19. (a) A pH meter could be placed into the mitochondrial matrix and intermembrane space to test Peter Mitchell’s
chemiosmotic theory. The pH of the intermembrane space should be significantly lower than the matrix.
(b) A voltmeter could be used since an electric gradient is formed between the intermembrane space and the mitochondrial matrix. If the positive probe of a voltmeter is placed in the
matrix and the negative probe placed in the intermembrane space, a voltage should be read on the voltmeter if electron transport is occurring.
(c) When a detergent is added to the mitochondria, the membranes leak. Since the membranes leak, H+ ions that enter the intermembrane space because of the electron transport chain
can diffuse back into the mitochondrial matrix quite easily. The protons do not need to be forced through ATP synthase, so ATP is not produced.
20. (a) The surface area of a teacher who is 180 cm tall and has a mass of 80 kg is 2.02 m2.
(b) Total energy content = basal energy req. surface area time
= 160 kJ/m2/h 2.02 m2 24 h
= 7756.8 kJ
(c) Student predictions will vary.
(d) Student answers will vary according to solution in (c).
Making Connections
21. (a) Mitochondria must be able to reproduce so that there will be enough of them after each successive cell division.
(b) All the mitochondria of a grown individual are from the mother’s egg; therefore, the mitochondrial DNA is identical on
the mother’s side.
(c) Student solutions will vary depending on the diseases chosen. Two examples of mitochondrial diseases are Leigh’s
syndrome and Pearson syndrome. Some very common diseases, such as Parkinson’s disease and Alzheimer’s disease,
are mitochondrial diseases.
Leigh’s syndrome (disease)
• Full name: Subacute necrotizing encephalomyelopathy
• Symptoms: Seizures, hypotonia (decreased muscle tone), fatigue, nystagmus (an involuntary rhythmic movement of
the eyes, usually from side to side), poor reflexes, eating and swallowing difficulties, breathing problems, poor motor
function, ataxia
• Causes: pyruvate dehydrogenase deficiency, NADH dehydrogenase deficiency, succinate dehydrogenase deficiency,
cytochrome c deficiency
22. (a) Vitamin B complex refers to the fact that the vitamin is made up of different B vitamins, not just a single type of
vitamin. Vitamin B complex contains vitamin B1, B2, B3, B5, B6, and B12.
(b) When a vitamin is water-soluble, it means that excess intake of the vitamin is not stored in the body as fat; it is excreted
with urine. These are vitamins that generally need to be replaced in the body often. Other examples of water-soluble
vitamins include folic acid, vitamin C, and pantothenic acid.
(c) Student solutions will vary. Two possible vitamins are shown below.
Vitamin B1
Thiamine enhances circulation and assists in blood formation, carbohydrate metabolism, and the production of
hydrochloric acid, which is important for proper digestion. Thiamine also optimizes brain function. It has a positive
effect on energy, growth, normal appetite, and learning capacity and is needed for muscle tone of the intestines,
stomach, and heart. Good sources include meats, liver, whole grain, nuts, legumes. Deficiency symptoms include
beriberi (a degenerative disease of the nerves marked by pain, the inability to move, and swelling), neurological effects,
and cardiovascular abnormalities.
Vitamin B3
Vitamin B3, also called niacin, niacinamide, or nicotinic acid, is an essential nutrient required by all humans for the
proper metabolism of carbohydrates, fats, and proteins, as well as for the production of hydrochloric acid for digestion.
Good sources include poultry, meat, fish, peanuts, and fortified grain. Deficiency symptoms include pellagra (which is
marked by dermatitis and gastrointestinal and central nervous system symptoms).
23. (a)
Function Hummingbird Human
Resting heart rate (beats/min) 1260 72
Breathing rate (breaths/min) 450 60
Fastest speed (km/h) 60 37
Average lifespan (years) 5 80
(b) If the average human were to consume as much food as a hummingbird, he or she would have to eat 103 kg of
hamburger per day.
2.3 RELATED PATHWAYS
Explore an Issue Take a Stand: Fetal Alcohol Syndrome
(Page 120)
Statement: Women should not drink even small amounts of alcoholic beverages while pregnant.
Student answers will vary. Some possible points that students may make include the following:
• Because it is not possible to determine a safe amount of alcohol consumption during pregnancy, women should not drink
any alcohol at all. It is not fair to the developing fetus to risk any lifelong damage that could occur due to alcohol
consumption.
• People are overreacting. Women drank and smoked during their pregnancies in the 1970s and 1980s, before all this research
was being conducted, and there has not been any study showing that all these children suffer any side effects from their
mothers’ habits.
• Small amounts of alcohol are probably safe for both mothers and their developing children. In nations such as France where
it is natural to have a glass of wine with a meal, normal children are born each day. There is no indication that a glass of
wine a day does any harm to a developing fetus.
• More studies need to be done to determine what effect small amounts of alcohol have on a fetus.
Section 2.3 Questions
(Page 124)
Understanding Concepts
1. When a cell has sufficient quantities of ATP, the excess acetyl-CoA is used to synthesize fatty acids.
2. Two differences in aerobic respiration and fermentation are that (1) aerobic respiration yields 36 ATP molecules per
glucose molecule and produces water and carbon dioxide, and that (2) fermentation yields 2 ATP molecules per glucose
molecule and produces ethanol or lactic acid.
3. A student will feel soreness in her chest and legs due to lactic acid buildup in her muscle tissues. This lactic acid buildup
is due to a low VO2 max as a result of the longer low-level activity.
4. A nonalcoholic fermentation product is carbon dioxide.
5. The final products of alcohol fermentation are ATP, carbon dioxide, and ethanol. The final products of lactic acid
fermentation are ATP and lactate.
6. (a) Two molecules of ethanol are produced for every molecule of glucose in alcoholic fermentation.
(b) Two molecules of carbon dioxide are produced during alcoholic fermentation, while lactic acid fermentation produces
no carbon dioxide.
(c) Fermentation is an anaerobic process and does not require oxygen.
7. Alcoholic fermentation occurs in yeast and plants roots when they are submerged.
8. (a) Lactic acid produced in muscle cells travels in the bloodstream to the liver, where it is oxidized back to pyruvate,
which then goes through the Krebs cycle and oxidative phosphorylation.
(b) Oxygen debt refers to the extra oxygen required by the liver to oxidize lactic acid to carbon dioxide and water (through
the aerobic pathway). Panting “pays” for the oxygen debt.
9. The presence of lactic acid in the muscle tissues leads to stiffness, soreness, and fatigue.
10. Maximum oxygen consumption, VO2 max, is a measure of a body’s capacity to generate the energy required for physical
activity. It is the maximum volume of oxygen that the cells of the body can remove from the bloodstream in one minute
per kilogram of body mass while the body experiences maximal exertion
CHAPTER 2 SUMMARY
(Page 132)
Chapter 2 Self-Quiz
1. False. During cellular respiration, the oxygen we inhale ends up
in the water we exhale or excrete.
2. False. Overall, glycolysis is an exergonic reaction.
3. True
4. False. T he following reactions take place in both plant and
animal cells:
C6H12O6 + 6O2 6 6CO2 + 6H2O
5. True
6. False. NADH is oxidized by the first protein complex of the
electron transport chain.
7. False. If a poison blocks the flow of protons through ATP
synthase, the Krebs cycle stops, but glycolysis will continue
8. False. The amino group is first removed from the amino acid as
waste and the rest of the amino acid is modified before
entering glycolysis or the Krebs cycle.
9. True
10. True
11. False. Maximum oxygen consumption, VO2 max, decreases as
people grow older.
12. (b)
13. (c)
14. (e)
15. (b)
16. (b)
17. (a)
18. (d)
19. (b)
Chapter 2 Review
(Pages 134–135)
Understanding Concepts
1.
2. (a) Glycolysis occurs in the cytoplasm.
(b) Pyruvate oxidation and the Krebs cycle occur in the
mitochondrial matrix.
(c) The electron transport chain and ATP synthesis occur in the
inner mitochondrial membrane.
3. (a) Ubiquinone (Q) is an electron carrier. As part of the
electron transport chain, it carries electrons from NADH
dehydrogenase to cytochrome b-c1 complex within the membrane.
(b) FADH2 is an electron carrier from the Krebs cycle that
transfers its two electrons to Q.
(c) Pyruvic acid is a product of glycolysis that enters the
mitochondrial matrix to undergo pyruvate oxidation and then
enters the Krebs cycle.
(d) ATP synthase is an enzyme complex located in the inner
mitochondrial membrane that uses the proton motive force to
generate ATP.
4. (a) Theoretically, NADH and FADH2 should generate three and
two ATP molecules, respectively.
(b) NADH passes its electrons to the first protein complex in the
electron transport chain, NADH hydrogenase. FADH2
transfers its electrons to the second protein in the chain,
ubiquinone (Q). The free energy released by the oxidation of
FADH2 is used to pump two protons into the intermembrane
space, while NADH oxidation pumps out three electrons.
The result is that two ATP are formed per FADH2, and three ATP
molecules are formed per mitochondrial NADH.
5. (a) The net gain in ATP after one molecule of glucose undergoes
cellular respiration is 36 ATP.
(b) The net gain in ATP after one molecule of glucose undergoes
alcoholic fermentation is 2 ATP.
6.
7. i. Glycolysis occurs in the cytoplasm.
ii. Pyruvate oxidation occurs in the mitochondrial matrix.
iii. The Krebs cycle occurs in the mitochondrial matrix.
iv. The electron transport chain and chemiosmosis occur in the
inner membrane of the mitochondria.
8. NAD+ accepts two electrons and one proton during glycolysis
and the Krebs cycle.
9. FADH2 is used as an electron acceptor in step 6 of the Krebs
cycle, because the reaction is not exergonic enough to reduce
NAD+ to NADH.
10. (a) An electrochemical gradient is created by pumping ions into
a space surrounded by a membrane that is impermeable to
ions. The gradient has two components: an electrical component
caused by a difference in charge across the membrane
and a chemical component caused by a difference in ion
concentration.
(b) An electrochemical gradient is created during electron
transport as the enzyme complexes move protons from NADH
and FADH2 into the intermembrane space. The intermembrane
space becomes an H+ reservoir because the membrane
is almost impermeable to protons. There is, therefore, a much
higher concentration of protons in the intermembrane
space than in the matrix. Also, protons are consumed in the
mitochondrial matrix as oxygen accepts electrons and form
water.
(c) The electrochemical gradient is used to power ATP synthesis
by the enzyme complex ATP synthase. The
electrochemical gradient stores free energy and this energy is
referred to as proton-motive force (PMF). Protons move
through ATP synthase in response to the PMF, reducing the
energy of the gradient. This energy drives the synthesis of
ATP from ADP and inorganic phosphate in the mitochondrial
matrix.
11. Yeast cells produce ATP from glucose by alcoholic
fermentation. NADH passes its hydrogen atoms to
acetylaldehyde,
which is formed when a carbon dioxide molecule is removed from
pyruvate using pyruvate decarboxylase. This produces
ATP, ethanol, and carbon dioxide.
12. The oxidized form of NAD has a positive charge, whereas the
reduced form is neutral. NADH contains two electrons and
one proton (H+), which come from a glucose molecule. NADH is the
reduced form of nicotinamide adenine dinucleotide,
while NAD+ is the oxidized form.
13. Muscle cells produce lactate from pyruvate when there is no
oxygen available to accept electrons from the cytochrome
oxidase complex.
14. Ethanol is made of two carbon atoms, while pyruvate is made
of three carbon atoms. Ethanol has one fewer carbon atom
that is lost as carbon dioxide.
15. Lactic acid is produced in the cytoplasm.
16. Two acetyl-CoA molecules are produced from one glucose
molecule during aerobic respiration.
17. (a) The Krebs cycle occurs in the mitochondrial matrix.
(b) The enzymes for the electron transport chain are located in
the inner mitochondrial membrane.
18. A cell that cannot undergo respiration or fermentation will die.
19. Thirty-two percent of the energy stored in glucose is captured
and stored in ATP during aerobic respiration.
20. A: inner mitochondrial membrane
B: cristae
C: mitochondrial matrix
D: outer mitochondrial space
2 1 . D in it r o p h e n o l r e d u c e s t h e a b ilit y o f a c e l l t o p r o d u c e A T P b y m a k i n g t h e in n e r m it o c h o n d r ia l m e m b r a n e le a k y . D N P t h u s
p r e v e n t s t h e c r e a t io n o f a c h e m io s m o t ic g r a d ie n t t h a t is u s e d t o g e n e r a t e A T P . T h e r e f o r e , c e lls w o u ld n o lo n g e r f u n c t io n
p r o p e r ly a n d a p e r s o n w o u ld d ie .
2 2 . M e t a b o lis m in a h e a r t u n d e r g o in g a h e a r t a t t a c k w o u ld s w i t c h f r o m c e llu la r r e s p ir a t io n t o la c t i c a c id f e r m e n t a t io n b e c a u s e
o f t h e la c k o f o x y g e n , w h ic h w o u ld b e c a u s e d b y a b l o c k e d c o r o n a r y a r t e r y . H o w e v e r , la c t i c a c id f e r m e n t a t io n d o e s n o t
p r o v id e e n o u g h e n e r g y t o k e e p t h e h e a r t b e a t in g a t a lif e -s u s t a in in g r a t e .
2 3 . I t is e s s e n t ia l t h a t m u s c le c e lls c o n t in u e t o c o n v e r t p y r u v a t e t o la c t a t e o r e ls e t h e m u s c le c e lls w o u ld c e a s e t o c o n t r a c t a n d
t h e c e lls w o u ld d ie .
2 4 . B a s a l m e t a b o lic r a t e r e f e r s t o t h e m in im u m e n e r g y r e q u ir e d t o r e m a in a liv e , w h e r e a s m a x im u m o x y g e n c o n s u m p t io n
r e f e r s t o t h e b o d y ’s m a x im u m c a p a c it y t o g e n e r a t e t h e e n e r g y r e q u i r e d f o r p h y s ic a l a c t iv it y .
2 5 . A p e r s o n w it h a h i g h e r V O 2 m a x w ill f e e l le s s t ir e d t h a n a p e r s o n w it h a lo w e r V O 2 m a x b e c a u s e t h e y a r e m o r e e f f i c ie n t
in s u p p ly in g o x y g e n t o t h e ir c e lls , a n d t h e r e f o r e , a c c u m u la t e le s s la c t a t e .
A p p ly in g I n q u ir y S k ills
2 6 . S t u d e n t s s h o u ld d e s ig n a n e x p e r im e n t t h a t h a s a t le a s t t h r e e r e p e a t s a n d t w o le v e l s o f o x y g e n c o n c e n t r a t io n s ( n o n e a n d
a t m o s p h e r ic le v e l s ) . S t u d e n t s s h o u ld s t a t e t h a t t h e y e a s t t h a t g r o w s b e s t in t h e p r e s e n c e o f o x y g e n is t h e a e r o b ic y e a s t a n d
t h e y e a s t t h a t g r o w s b e s t in t h e a b s e n c e o f o x y g e n in t h e a n a e r o b ic y e a s t .
2 7 . A h ig h c o n c e n t r a t io n o f á -k e t o g lu t a r a t e in t h e u r in e w o u ld b e d u e t o in e f f e c t iv e p r o t e in c a t a b o lis m . P r o lin e is c o n v e r t e d
in t o á -k e t o g lu t a r a t e , w h ic h t h e n e n t e r s c e llu la r r e s p ir a t io n a s a n in t e r m e d ia t e . H i g h le v e ls o f á -k e t o g lu t a r a t e m a y in d ic a t e
g e n e t ic p r o b le m s w it h t h e in f a n t .
M a k i n g C o n n e c t io n s
2 8 . (a ) S o y s a u c e , t o f u , s o y m ilk , m is o (a f e r m e n t e d s o y b e a n p a s t e ), s o y b u t t e r
( b ) S o y s a u c e a n d m is o
( c ) P e d io c o c c u s h a lo p h iu s , S a c c h a r o m y c e s r o u x ii, a n d T o r u lo p s is v e r s a t ilis
( d ) S o y s a u c e is p r o d u c e d a s f o llo w s :
1 . S o y b e a n s a n d w h e a t a r e b le n d e d u n d e r c o n t r o lle d c o n d it io n s . N e x t , t h e m ix t u r e is in o c u la t e d w it h m ic r o o r g a n is m s
a n d a llo w e d t o m a t u r e f o r s e v e r a l d a y s in la r g e , v a t s t h r o u g h w h ic h a ir is c ir c u la t e d .
2 . T h e r e s u lt in g c u lt u r e , o r k o j i, is t h e n t r a n s f e r r e d t o f e r m e n t a t io n t a n k s a n d m ix e d w it h s a lt w a t e r t o p r o d u c e a m a s h
c a lle d m o r o m i. T h e m o r o m i is a llo w e d t o f e r m e n t f o r s e v e r a l m o n t h s w it h v a r io u s la c t ic a c id b a c t e r ia a n d y e a s t s . T h e
f e r m e n t a t io n p r o c e s s c r e a t e s t h e d is t in c t f la v o u r a n d f r a g r a n c e o f s o y s a u c e .
3 . A f t e r m o r o m i f e r m e n t a t io n , t h e r a w s o y s a u c e is s e p a r a t e d f r o m t h e s o lid s b y p r e s s in g it t h r o u g h m a n y la y e r s o f
c lo t h . T h e r e s u lt in g liq u id is f in a lly p a s t e u r iz e d a n d p a c k a g e d .
2 9 . ( a ) L a c t o b a c illu s b a c t e r ia u n d e r g o la c t i c a c id f e r m e n t a t io n .
( b ) T h is f o r m o f m e t a b o lis m in c r e a s e s t h e s h e lf lif e o f f o o d b y in c r e a s in g t h e a c id it y t o le v e l s t h a t in h ib it t h e g r o w t h o f
b a c t e r ia .
E x t e n s io n
3 0 . (a ) N o m in im u m d r in k in g a g e in J a m a ic a , P o la n d , P o r t u g a l , a n d S w e d e n ; 1 4 y e a r s in S w it z e r la n d ; 1 6 y e a r s in I t a ly ,
F r a n c e , a n d G e r m a n y ; 1 8 y e a r s in C h ile , B r i t a in ; 1 9 y e a r s in C a n a d a ; 2 0 y e a r s in J a p a n ; 2 1 y e a r s in U n it e d S t a t e s .
( b ) I n m o s t c a s e s t h e r e a s o n s f o r t h e r e s t r ic t io n s a r e t o r e d u c e a l c o h o l d e p e n d e n c e a n d a b u s e , a llo w f o r m a t u r it y a n d
r e s p o n s ib ilit y b e f o r e d r i n k in g , e n f o r c e p a r e n t a l r ig h t s , a n d r e s p o n d t o c u lt u r a l , r e lig i o u s , a n d p o lit ic a l c o n c e r n s .
( c ) E t h a n o l a f f e c t s t h e c e n t r a l n e r v o u s s y s t e m . I t is a d e p r e s s a n t t h a t in h ig h e n o u g h c o n c e n t r a t io n s , m a y a c t a s a g e n e r a l
a n a e s t h e t ic . I t s u p p r e s s e s c e r t a in b r a in f u n c t io n s . A t v e r y lo w d o s e s , it a c t s a s a s t im u la n t , s u p p r e s s in g c e r t a in
in h ib it o r y b r a in f u n c t io n s . A s e t h a n o l’s c o n c e n t r a t io n in c r e a s e s , f u r t h e r s u p p r e s s io n o f b r a in f u n c t io n s p r o d u c e t h e
c la s s ic s y m p t o m s o f in t o x ic a t io n : s lu r r e d s p e e c h , u n s t e a d y w a lk , d is t u r b e d s e n s o r y p e r c e p t io n s , a n d s lo w r e a c t io n t o
s t im u li. A t v e r y h ig h c o n c e n t r a t io n s , a n in t o x ic a t e d p e r s o n w ill f a ll a s le e p a n d b e v e r y d if f ic u lt t o w a k e . I f t h e p e r s o n is
a w a k e n e d , h e o r s h e m a y b e u n a b le t o m o v e v o lu n t a r ily . W h e n b l o o d le v e l s r e a c h 0 . 4 p e r c e n t , u n c o n s c io u s n e s s r e s u lt s .
A b o v e 0 .5 p e r c e n t , t h e b r e a t h in g c e n t r e o f t h e b r a in a n d t h e b e a t i n g a c t i o n o f t h e h e a r t c a n b e a n a e s t h e t i z e d , r e s u lt in g
in d e a t h .
( d ) S t u d e n t o p in io n s w ill v a r y . T h e r e is n o c o r r e c t a n s w e r , b u t p a p e r s m u s t b e w e ll r e a s o n e d a n d t h o u g h t o u t .
3 1 . (a ) p a lm it a t e + 7 C o A + 7 F A D + 7 N A D + + 7 H 2 O 6 8 a c e t y l-C o A + 7 F A D H 2 + 7 N A D H + 5 H +
1. F rom 7 N A D H a nd 7 FA D H 2 :
2 .5 A T P p e r N A D H = 2 .5
7 = 1 7 .5 A T P
1 .5 A T P p e r F A D H 2 = 1 .5
7 = 1 0 .5 A T P
7 A T P m o le c u le s a r e u s e d
T o t a l A T P p r o d u c e d f r o m 7 N A D H a n d 7 F A D H 2 = 1 7 .5 + 1 0 .5 – 7 = 2 1 A T P