DHN 311 REVISION EXAM 2025/2026 QUESTIONS WITH
SOLUTIONS RATED A+
✔✔substrate-level phosphorylation - ✔✔the formation of ATP at the level of an
enzymatic reaction
✔✔ADP; intermediate - ✔✔Substrate-level phosphorylation involves the direct synthesis
of ATP from _____ and a reactive ________.
✔✔intermediate - ✔✔the product of one enzymatic reaction, which tends to be the
substrate for the next enzyme in the metabolic pathway
✔✔minor - ✔✔Substrate-level phosphorylation is a relatively ______ contributor to the
total synthesis of triphosphates by cells.
✔✔substrate-level phosphorylation - ✔✔The last step of glycolysis is an example of...
✔✔reaction coupling - ✔✔the tendency of unfavorable biological reactions to occur
concurrently with favorable reactions, often catalyzed by a single enzyme
✔✔electron transport chain (respiratory chain) - ✔✔a series of proteins in which the
high-energy electrons from the Krebs cycle are used to convert ADP into ATP
✔✔mitochondria - ✔✔The electron transport chain occurs in the _________.
✔✔major - ✔✔The electron transport chain is a _______ contributor of ATP production.
✔✔cellular respiration - ✔✔process by which cells consumer O2 and produce CO2
✔✔glucose (other sugars); fatty acids; most amino acids; citric acid cycle; electron
transport chain - ✔✔In aerobic organisms, _______, _______ ______, and _____
_____ _____ are ultimately oxidized to CO2 and H2O. This happens via the ______
______ ______ and the _______ ______ _______.
✔✔acetyl group - ✔✔Before entering the citric acid cycle, the carbon skeletons of
sugars and FAs are degraded to the ______ _____ of acetyl-CoA.
✔✔acetyl-CoA - ✔✔In stage 1 of cellular respiration, glucose, FAs, and some amino
acids are oxidized to yield ________.
✔✔acetyl groups; electron carriers/reducing agents - ✔✔In stage 2 of cellular
respiration, ______ ______ are oxidized in the citric acid cycle. This results in the
generation of...
,✔✔NADH; FADH2; ATP - ✔✔In stage 3 of cellular respiration, electrons carried by
_____ and ______ (reducing agents) are funneled into the ETC to make ______.
✔✔glycolysis - ✔✔the breakdown of glucose by enzymes, releasing energy and
pyruvate
✔✔catabolic - ✔✔Glycolysis is an example of a(n) anabolic/catabolic metabolic
pathway.
✔✔10; energy investment stage and energy generation stage - ✔✔There are ___ key
steps in glycolysis. They can be divided into two stages:
✔✔in the cytosol - ✔✔Where does glycolysis occur?
✔✔aerobic; anaerobic; products; energy production - ✔✔Glycolysis can be _______ or
______. The presence of O2 dictates _______ and ______ ________.
✔✔-oxioreductases
-transferases
-hydrolases
-lyases
-isomerases
-ligases/synthetases - ✔✔the six major classes of enzymes
✔✔redox - ✔✔Oxioreductases catalyze _______ reactions.
✔✔dehydrogenase - ✔✔an important type of oxioreductase
✔✔substrate; enzyme - ✔✔Generally, in redox reactions, the _______ undergoes either
oxidation or reduction, while the ______ temporarily does the opposite but eventually
returns to its original form.
✔✔-loss of one or more electrons
-gain of oxygen
-loss of hydrogen - ✔✔possible types of oxidation
✔✔-gain of one or more electrons
-loss of oxygen
-gained hydrogen - ✔✔possible types of reduction
✔✔functional group; do not - ✔✔Transferases catalyze the transfer of a ______ ______
from one molecule to another. These reactions do/do not involve oxidation and
reduction.
, ✔✔phosphatase - ✔✔an important type of hydrolase
✔✔cleavage; water (as an H and a OH) - ✔✔Hydrolases catalyze the _______ of a
bond through the insertion of _______.
✔✔transferase; digestive - ✔✔Hydrolases are essentially _______ enzymes since they
are transferring a water molecule. _______ enzymes fall within this classification.
✔✔decarboxylases, synthetases - ✔✔important types of lyases
✔✔removal; cleaving - ✔✔Lyases catalyze the ______ of a group by ______ the bond
between two molecules.
✔✔double bond; addition - ✔✔A reaction with a lyase can accompany the formation of
a ______ _____ or the _______ of a group to a double bond.
✔✔-double bond in product
-one substrate to two products - ✔✔hints of reactions with lyases
✔✔conversion; molecular; structural - ✔✔Isomerases catalyze the _______ of one
isomer to another. Isomers are compounds that have the same _______ formula but
different _______ formulas.
✔✔one reactant, one product - ✔✔hint of reactions with isomerases
✔✔carbon; oxygen; sulfur; nitrogen - ✔✔Ligases catalyze the formation of bonds
between ______ and a variety of other atoms, including ______, ______, and ______.
✔✔ligases/synthetases - ✔✔"linking" enzymes
✔✔energy - ✔✔Forming bonds catalyzed by ligases requires _______.
✔✔-energy invested
-2 substrates, 1 product - ✔✔hints of reactions with ligases
✔✔substrate level - ✔✔ATP generated from glycolysis is considered ______ ______
formation of ATP.
✔✔CO2 - ✔✔After pyruvate is produced through glycolysis, it can then go on to another
pathway to be completely oxidized to _____.
✔✔glucose and fructose - ✔✔the two sugars that can directly enter glycolysis
SOLUTIONS RATED A+
✔✔substrate-level phosphorylation - ✔✔the formation of ATP at the level of an
enzymatic reaction
✔✔ADP; intermediate - ✔✔Substrate-level phosphorylation involves the direct synthesis
of ATP from _____ and a reactive ________.
✔✔intermediate - ✔✔the product of one enzymatic reaction, which tends to be the
substrate for the next enzyme in the metabolic pathway
✔✔minor - ✔✔Substrate-level phosphorylation is a relatively ______ contributor to the
total synthesis of triphosphates by cells.
✔✔substrate-level phosphorylation - ✔✔The last step of glycolysis is an example of...
✔✔reaction coupling - ✔✔the tendency of unfavorable biological reactions to occur
concurrently with favorable reactions, often catalyzed by a single enzyme
✔✔electron transport chain (respiratory chain) - ✔✔a series of proteins in which the
high-energy electrons from the Krebs cycle are used to convert ADP into ATP
✔✔mitochondria - ✔✔The electron transport chain occurs in the _________.
✔✔major - ✔✔The electron transport chain is a _______ contributor of ATP production.
✔✔cellular respiration - ✔✔process by which cells consumer O2 and produce CO2
✔✔glucose (other sugars); fatty acids; most amino acids; citric acid cycle; electron
transport chain - ✔✔In aerobic organisms, _______, _______ ______, and _____
_____ _____ are ultimately oxidized to CO2 and H2O. This happens via the ______
______ ______ and the _______ ______ _______.
✔✔acetyl group - ✔✔Before entering the citric acid cycle, the carbon skeletons of
sugars and FAs are degraded to the ______ _____ of acetyl-CoA.
✔✔acetyl-CoA - ✔✔In stage 1 of cellular respiration, glucose, FAs, and some amino
acids are oxidized to yield ________.
✔✔acetyl groups; electron carriers/reducing agents - ✔✔In stage 2 of cellular
respiration, ______ ______ are oxidized in the citric acid cycle. This results in the
generation of...
,✔✔NADH; FADH2; ATP - ✔✔In stage 3 of cellular respiration, electrons carried by
_____ and ______ (reducing agents) are funneled into the ETC to make ______.
✔✔glycolysis - ✔✔the breakdown of glucose by enzymes, releasing energy and
pyruvate
✔✔catabolic - ✔✔Glycolysis is an example of a(n) anabolic/catabolic metabolic
pathway.
✔✔10; energy investment stage and energy generation stage - ✔✔There are ___ key
steps in glycolysis. They can be divided into two stages:
✔✔in the cytosol - ✔✔Where does glycolysis occur?
✔✔aerobic; anaerobic; products; energy production - ✔✔Glycolysis can be _______ or
______. The presence of O2 dictates _______ and ______ ________.
✔✔-oxioreductases
-transferases
-hydrolases
-lyases
-isomerases
-ligases/synthetases - ✔✔the six major classes of enzymes
✔✔redox - ✔✔Oxioreductases catalyze _______ reactions.
✔✔dehydrogenase - ✔✔an important type of oxioreductase
✔✔substrate; enzyme - ✔✔Generally, in redox reactions, the _______ undergoes either
oxidation or reduction, while the ______ temporarily does the opposite but eventually
returns to its original form.
✔✔-loss of one or more electrons
-gain of oxygen
-loss of hydrogen - ✔✔possible types of oxidation
✔✔-gain of one or more electrons
-loss of oxygen
-gained hydrogen - ✔✔possible types of reduction
✔✔functional group; do not - ✔✔Transferases catalyze the transfer of a ______ ______
from one molecule to another. These reactions do/do not involve oxidation and
reduction.
, ✔✔phosphatase - ✔✔an important type of hydrolase
✔✔cleavage; water (as an H and a OH) - ✔✔Hydrolases catalyze the _______ of a
bond through the insertion of _______.
✔✔transferase; digestive - ✔✔Hydrolases are essentially _______ enzymes since they
are transferring a water molecule. _______ enzymes fall within this classification.
✔✔decarboxylases, synthetases - ✔✔important types of lyases
✔✔removal; cleaving - ✔✔Lyases catalyze the ______ of a group by ______ the bond
between two molecules.
✔✔double bond; addition - ✔✔A reaction with a lyase can accompany the formation of
a ______ _____ or the _______ of a group to a double bond.
✔✔-double bond in product
-one substrate to two products - ✔✔hints of reactions with lyases
✔✔conversion; molecular; structural - ✔✔Isomerases catalyze the _______ of one
isomer to another. Isomers are compounds that have the same _______ formula but
different _______ formulas.
✔✔one reactant, one product - ✔✔hint of reactions with isomerases
✔✔carbon; oxygen; sulfur; nitrogen - ✔✔Ligases catalyze the formation of bonds
between ______ and a variety of other atoms, including ______, ______, and ______.
✔✔ligases/synthetases - ✔✔"linking" enzymes
✔✔energy - ✔✔Forming bonds catalyzed by ligases requires _______.
✔✔-energy invested
-2 substrates, 1 product - ✔✔hints of reactions with ligases
✔✔substrate level - ✔✔ATP generated from glycolysis is considered ______ ______
formation of ATP.
✔✔CO2 - ✔✔After pyruvate is produced through glycolysis, it can then go on to another
pathway to be completely oxidized to _____.
✔✔glucose and fructose - ✔✔the two sugars that can directly enter glycolysis
