BIOL 334 FINAL EXAM QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2026
Pyruvate produced by cytosolic glycolysis is a key substrate for mitochondrial respiration in animals
and plants. How does pyruvate pass through the outer mitochondrial membrane - Answers Through a
porin
Which compound links glycolysis, the TCA cycle and fatty acid synthesis - Answers acetyl-CoA
Which biochemical terms best describe the enzyme that catalyze the following pair of reactions:
Ethanol + NAD^+ -> Acetaldehyde + NADH
Glycerol + ATP -> Glycerol-3-phosphate + ADP - Answers dehydrogenase and kinase
Which of the following is incorrect for:
Fundamental cellular requirements for anaerobic energy production generally include: - Answers a
pronounced "Paster Effect"
The decarboxylation of pyruvate to acetyl-CoA is highly exergonic. How is the energy released by this
reaction conserved by animals or plants? - Answers Through the reduction of NAD+ to NADH
The conversion of one mole of glucose 6 phosphate to tow moles of ethanol by the fermentative
pathway of anoxia tolerant goldfish is accompanied by a net yield of: - Answers 3 moles of ATP
What is the metabolic basis for Lou Gehrig's disease (i.e. ALS= Amyotrophic Lateral Sclerosis) -
Answers reduced cellular ability to convert superoxide radicals into hydrogen peroxide
Infoldings of the inner mitochondrial membrane are called - Answers Cristae
Analysis of fully purified native enzyme using the technique of mass spectrometry together with
internet (bioinformatics) databases allow us to: - Answers identify the encoding gene
identify type(s) and site(s) of post translational modifications that occur in vivo
What type(s) of cells or tissues would you expect to find activities of isocitrate lyase - Answers
bacteria (e.g. E.coli) growing on acetate
Fill in the blank: " A huge accumulation of _____________ was achieved in seeds of transgenic rice by
introduction of a gene encoding an allosteric mutant of anthranilate synthase. " - Answers tryptophan
What allosteric features of cytosolic ATP-dependent phosphofructokinase (ATP-PFK) and PPi-
dependent phosphofructokinase (PPi-PFK) will promote PPi-PFK activity but suppress ATP-PFK activity
during sever Pi starvation in plants? - Answers plant PPi-PFK is inhibited by Pi, whereas ATP-PFK is
activated by Pi
Which of the following does not involve a mitochondrial process? - Answers ATP production in
Entamoeba histolytics (a eukaryotic 'prostist' that causes amoebic dysentery in humans)
When lots of oxygen is available, the oxidation of 1 pyruvate molecule into 3(CO2), by the combined
reactions of the pyruvate dehydrogenase complex and the TCA cycle (by healthy, respiring animal
mitochondria) leads to the net productions of: - Answers 15 ATP molecules
A major goal of plant biotech is to reduce or eliminate agriculture's dependence on precious fresh
water via the production of salt-tolerant crops. SOS1 is an integral plasma membrane protein that
catalyzes the active transport of sodium ions out of plants. Why did transgenic plants that only over
expressed SOS1 not become more salt tolerant? - Answers Transgenic plants that only over expressed
SOS1 didn't become more salt tolerant because SOS1 is activated by SOS2 which in turn is activated
by SOS3. Therefore all 3 are needed to make salt tolerant plants
Sperm whales are known to dice up to 3 km to locate their prey. However, deep water has a
significantly greater density than shallow water. How does its spermaceti organ help the sperm whale
to watch the density of surrounding water? - Answers Spermaceti oil (TG) helps the sperm whale to
match the density of water by:
Shallow water = less dense and warmer = liquid (less dense) spermaceti
Deep water = more dense and colder = solid (more dense) spermaceti
Fill in the blank: " Conversion of triglycerides into fatty acids and glycerol in mammalian adipocytes
will occur when an enzyme named __________ becomes activated by ____________ - Answers TG
lipase
cAMP-dependent PK
List two fundamental properties of 'signal transduction metabolites' such as cyclic-AMP or fructose-
2,6-P2 - Answers only used to regulate metabolism
work at [very low] (uM range)
Spell out OPPP - Answers Oxidative Pentose Phosphate Pathway
What is the role of the OPPP - Answers generate MADPH for reductive anabolic reactions
, How was metabolic engineering used to prove that PPi helps potato plants survive hypoxia stress? -
Answers - E.coli PPiase targeted to cytosol of transgenic potato
- PPiase catalyzes wasteful PPi hydrolysisi -> 2Pi
- Growth and viability of resulting PPi-deficient transgenic plants as greatly decreased during hypoxia
stress
How was metabolic engineering used to prove that SuperOxide Dismutase (SOD) helps to extend the
lifespan of mice? - Answers metabolic engineered a 'knockout' of mitochondrial SOD enzyme in mice
resulted in their very premature death. Non transgenic mice (wild type with SOD enzyme) lived much
longer than those without SOD enzyme
Anhydrobiotic species such as tardigrades or resurrection plants accumulate relatively massive
intracellular concentrations of sugar alcohols such as glycerol when undergoing anhydrobiosis.
a.) how does this adaptation help anhydrobiotic organisms survive desiccation?
b.) Why would accumulation of high intracellular concentrations of glucose be maladaptive to the
survival of these species during anhydrobiosis? - Answers a.) glycerol in an effective anti-freeze and
stabilizes membranes and proteins when liquid H2O is absent
b.) glucose contains a chemically reactive carbonyl group that can spontaneously form a harmful
covalent bond with NH2, which damages and inactivates proteins
How is proton motive force used to produce ATP during oxidative phosphorylation? - Answers -
energy produced by exergonic flow through the ETC is couples with endergonic transport of H+ ions
across the membrane of the mitochondria
- PMF provides energy for transport of metabolites and proteins from cytosol into mitochondrial
matrix
- Allows ADP and Pi to be exchanged for ATP
- Transmembrane flow of proteins down their concentration gradient through specific channels
provides energy for ATP synthesis
How is proton motive force use to create heat rather than ATP during ' non-shivering thermogenesis '
of mammalian brown fat tissue? - Answers - heat generation by uncoupled mitochondria 'short
circuit' ATP synthase
- thermogenin dissipates PMF
When do females and males have significant amounts of brown fat tissue? - Answers newborns
What feature of plant mitochondria not found in vertebrate animals allows thermogenic flowers such
as spadix of eastern skunk cabbage to produce heat? - Answers non-energy conserving alternative ETC
that allows for thermogenesis
What beneficial role does flower thermogenesis play? - Answers Attracts pollinators
How can ATP function as both a substrate and an inhibitor of muscle PFK? - Answers because levels of
ATP control activation(decreased ATP)/inhibition(increased ATP) of PFK/PK and ATP can also act as a
co-substrate for ATP-PFK
What compound effectively relives (reduces) the inhibition of animal PFK by high ATP concentrations?
- Answers fructose-2,6-biphosphate
Mechanical damage to plant cells often triggers their production of significant amounts of protease
inhibitor proteins that have no effect on activity of any endogenous plant proteases. How does this
adaptation help plants to survive in their natural environment? - Answers - Protease inhibitors protein
are within the plant cell wall
- when an insect eats this, the protein inhibitors bind directly to the insects gut proteases and gives in
a bad case of indigestion
- This discourages the insect from eating the plant, allowing the plant to avoid herbivory
Pyruvate kinase is a key regulatory pacemaker enzyme of animal and plant glycolysis.
Describe the sequence of events (signal transduction pathway) whereby elevated glucagon
concentrations in our bloodstream leads in inactivation of PK in the cytosol of hepatocytes (liver cells)
- Answers - Starvation pf humans results in pancreatic secretion of peptide hormone glucagon into the
blood stream
- In liver cells (hepatocytes) this results in elevated intracellular levels of cyclic-AMP and hence
phosphorylation of the bifunctional PFK-2/FBPase-2 enzyme which results in decreased levels of
fructose-2,6-biphosphate
- Which therefore promotes gluconeogenesis (GNG) by relieving inhibition of FBPase-1 and prevents
glycolysis
Pyruvate produced by cytosolic glycolysis is a key substrate for mitochondrial respiration in animals
and plants. How does pyruvate pass through the outer mitochondrial membrane - Answers Through a
porin
Which compound links glycolysis, the TCA cycle and fatty acid synthesis - Answers acetyl-CoA
Which biochemical terms best describe the enzyme that catalyze the following pair of reactions:
Ethanol + NAD^+ -> Acetaldehyde + NADH
Glycerol + ATP -> Glycerol-3-phosphate + ADP - Answers dehydrogenase and kinase
Which of the following is incorrect for:
Fundamental cellular requirements for anaerobic energy production generally include: - Answers a
pronounced "Paster Effect"
The decarboxylation of pyruvate to acetyl-CoA is highly exergonic. How is the energy released by this
reaction conserved by animals or plants? - Answers Through the reduction of NAD+ to NADH
The conversion of one mole of glucose 6 phosphate to tow moles of ethanol by the fermentative
pathway of anoxia tolerant goldfish is accompanied by a net yield of: - Answers 3 moles of ATP
What is the metabolic basis for Lou Gehrig's disease (i.e. ALS= Amyotrophic Lateral Sclerosis) -
Answers reduced cellular ability to convert superoxide radicals into hydrogen peroxide
Infoldings of the inner mitochondrial membrane are called - Answers Cristae
Analysis of fully purified native enzyme using the technique of mass spectrometry together with
internet (bioinformatics) databases allow us to: - Answers identify the encoding gene
identify type(s) and site(s) of post translational modifications that occur in vivo
What type(s) of cells or tissues would you expect to find activities of isocitrate lyase - Answers
bacteria (e.g. E.coli) growing on acetate
Fill in the blank: " A huge accumulation of _____________ was achieved in seeds of transgenic rice by
introduction of a gene encoding an allosteric mutant of anthranilate synthase. " - Answers tryptophan
What allosteric features of cytosolic ATP-dependent phosphofructokinase (ATP-PFK) and PPi-
dependent phosphofructokinase (PPi-PFK) will promote PPi-PFK activity but suppress ATP-PFK activity
during sever Pi starvation in plants? - Answers plant PPi-PFK is inhibited by Pi, whereas ATP-PFK is
activated by Pi
Which of the following does not involve a mitochondrial process? - Answers ATP production in
Entamoeba histolytics (a eukaryotic 'prostist' that causes amoebic dysentery in humans)
When lots of oxygen is available, the oxidation of 1 pyruvate molecule into 3(CO2), by the combined
reactions of the pyruvate dehydrogenase complex and the TCA cycle (by healthy, respiring animal
mitochondria) leads to the net productions of: - Answers 15 ATP molecules
A major goal of plant biotech is to reduce or eliminate agriculture's dependence on precious fresh
water via the production of salt-tolerant crops. SOS1 is an integral plasma membrane protein that
catalyzes the active transport of sodium ions out of plants. Why did transgenic plants that only over
expressed SOS1 not become more salt tolerant? - Answers Transgenic plants that only over expressed
SOS1 didn't become more salt tolerant because SOS1 is activated by SOS2 which in turn is activated
by SOS3. Therefore all 3 are needed to make salt tolerant plants
Sperm whales are known to dice up to 3 km to locate their prey. However, deep water has a
significantly greater density than shallow water. How does its spermaceti organ help the sperm whale
to watch the density of surrounding water? - Answers Spermaceti oil (TG) helps the sperm whale to
match the density of water by:
Shallow water = less dense and warmer = liquid (less dense) spermaceti
Deep water = more dense and colder = solid (more dense) spermaceti
Fill in the blank: " Conversion of triglycerides into fatty acids and glycerol in mammalian adipocytes
will occur when an enzyme named __________ becomes activated by ____________ - Answers TG
lipase
cAMP-dependent PK
List two fundamental properties of 'signal transduction metabolites' such as cyclic-AMP or fructose-
2,6-P2 - Answers only used to regulate metabolism
work at [very low] (uM range)
Spell out OPPP - Answers Oxidative Pentose Phosphate Pathway
What is the role of the OPPP - Answers generate MADPH for reductive anabolic reactions
, How was metabolic engineering used to prove that PPi helps potato plants survive hypoxia stress? -
Answers - E.coli PPiase targeted to cytosol of transgenic potato
- PPiase catalyzes wasteful PPi hydrolysisi -> 2Pi
- Growth and viability of resulting PPi-deficient transgenic plants as greatly decreased during hypoxia
stress
How was metabolic engineering used to prove that SuperOxide Dismutase (SOD) helps to extend the
lifespan of mice? - Answers metabolic engineered a 'knockout' of mitochondrial SOD enzyme in mice
resulted in their very premature death. Non transgenic mice (wild type with SOD enzyme) lived much
longer than those without SOD enzyme
Anhydrobiotic species such as tardigrades or resurrection plants accumulate relatively massive
intracellular concentrations of sugar alcohols such as glycerol when undergoing anhydrobiosis.
a.) how does this adaptation help anhydrobiotic organisms survive desiccation?
b.) Why would accumulation of high intracellular concentrations of glucose be maladaptive to the
survival of these species during anhydrobiosis? - Answers a.) glycerol in an effective anti-freeze and
stabilizes membranes and proteins when liquid H2O is absent
b.) glucose contains a chemically reactive carbonyl group that can spontaneously form a harmful
covalent bond with NH2, which damages and inactivates proteins
How is proton motive force used to produce ATP during oxidative phosphorylation? - Answers -
energy produced by exergonic flow through the ETC is couples with endergonic transport of H+ ions
across the membrane of the mitochondria
- PMF provides energy for transport of metabolites and proteins from cytosol into mitochondrial
matrix
- Allows ADP and Pi to be exchanged for ATP
- Transmembrane flow of proteins down their concentration gradient through specific channels
provides energy for ATP synthesis
How is proton motive force use to create heat rather than ATP during ' non-shivering thermogenesis '
of mammalian brown fat tissue? - Answers - heat generation by uncoupled mitochondria 'short
circuit' ATP synthase
- thermogenin dissipates PMF
When do females and males have significant amounts of brown fat tissue? - Answers newborns
What feature of plant mitochondria not found in vertebrate animals allows thermogenic flowers such
as spadix of eastern skunk cabbage to produce heat? - Answers non-energy conserving alternative ETC
that allows for thermogenesis
What beneficial role does flower thermogenesis play? - Answers Attracts pollinators
How can ATP function as both a substrate and an inhibitor of muscle PFK? - Answers because levels of
ATP control activation(decreased ATP)/inhibition(increased ATP) of PFK/PK and ATP can also act as a
co-substrate for ATP-PFK
What compound effectively relives (reduces) the inhibition of animal PFK by high ATP concentrations?
- Answers fructose-2,6-biphosphate
Mechanical damage to plant cells often triggers their production of significant amounts of protease
inhibitor proteins that have no effect on activity of any endogenous plant proteases. How does this
adaptation help plants to survive in their natural environment? - Answers - Protease inhibitors protein
are within the plant cell wall
- when an insect eats this, the protein inhibitors bind directly to the insects gut proteases and gives in
a bad case of indigestion
- This discourages the insect from eating the plant, allowing the plant to avoid herbivory
Pyruvate kinase is a key regulatory pacemaker enzyme of animal and plant glycolysis.
Describe the sequence of events (signal transduction pathway) whereby elevated glucagon
concentrations in our bloodstream leads in inactivation of PK in the cytosol of hepatocytes (liver cells)
- Answers - Starvation pf humans results in pancreatic secretion of peptide hormone glucagon into the
blood stream
- In liver cells (hepatocytes) this results in elevated intracellular levels of cyclic-AMP and hence
phosphorylation of the bifunctional PFK-2/FBPase-2 enzyme which results in decreased levels of
fructose-2,6-biphosphate
- Which therefore promotes gluconeogenesis (GNG) by relieving inhibition of FBPase-1 and prevents
glycolysis
