BIOL 100
Rec.
Jeffry Guerrero, CUNY Hunter College
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Updates
Focus
Todays
Agenda Questions/Discussions
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Updates
▪ Exam next week
▪ Online extra credit quizzes
▪ Check out supplements!
▪ Try and answer questions without your notes, and once the
answer is reveled write down anything you didn’t know or
write anything that might be helpful.
▪ Please raise your voice when speaking ☺
▪ Don’t forget to do textbook questions as well!
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Focus Questions /Discussion
Focus (chapter 8)
▪ Anabolism vs catabolism
▪ Laws of thermodynamics
▪ ATP coupling
▪ Activation energy
▪ Types of enzymes
▪ Competitive vs non-competitive
▪ Allosteric regulation and cooperativity and it’s examples
Focus PAGE 4
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Focus (chapter 9)
▪ Advice: Draw it to know it
▪ There’s so many videos and practice questions on this topic,
utilize the internet to help your understand
▪ But there’s also more you don’t need to know
▪ So pay special attention to Dr. Sheppard's Lecture
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Focus (chapter 9)
▪ Phosphofructosekinase-1 and what inhibits/activates it
▪ Products in each step
▪ When NADH/FADH2 are made vs it’s opposites.
▪ Overall NET
▪ When steps are irreversible
▪ Citric acid is our start and oxaloacetate our end
▪ True purpose of fermentation
▪ How fats and amino acids are used to make ATP
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Questions/Discussion
Which graph represents non-allosteric enzyme in absence and
presence of non-competitive inhibitor? (blue = absence)
A. 1
B. 2
Reaction rate ->
C. 3
D. 4
E. None
Substrate concentration ->
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Questions/Discussion
Energy-requiring reactions can occur in biological systems
because enzymes allow their coupling to other reactions with
A. An increase in entropy
B. A low activation energy
C. No inhibitors
D. Products of lower free energy than the reactants
E. Oxidation-reduction
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Questions/Discussion
What type of enzyme is this? Hint: The enzyme is a kinase
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Enzyme Type Function
Oxidoreductase Redox aka transfer of electrons (OIL RIG)
Transferase Functional group transfer to new molecule
Hydrolase Catabolic, breaks down into 2 or more piece using water
Lyase Breaking down molecule (covalent) into 2 or more pieces
without water or oxidation.
Isomerase Functional group transfer within same molecule
Ligase Join 2 molecules together (covalent)
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Questions/Discussion
What type of enzyme is this? Hint: The enzyme is a
phosphatase
Source: http://clfs690.alivetek.org/CLFS690/glycolglucojmol/glucosephosphatasejmol.htm
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Questions/Discussion
You place an enzyme into a more acidic solution than blood (pH of
7.35-7.45). You notice that rate of product formation increased with
this environmental shift. You can conclude:
A. The enzyme should exist within a lysosome.
B. The enzyme’s higher levels of structure became slightly
denatured.
C. The enzyme’s higher levels of structure became more stable.
D. The enzyme’s optimal environment for high levels of functioning
is an alkaline solution.
E. The enzyme was more efficient at lowering the free energy of
the reaction at the lower pH than at the blood pH.
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Questions/Discussion
The reason that the curve reaches a plateau,
and does not increase any further is because
A. The active site is saturated with substrate
B. There is a competitive inhibitor present
C. There is a non-competitive inhibitor present
D. The allosteric enzyme is locked in an inactive
conformation
E. All substrate has been converted to product
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Questions/Discussion
The depicted reaction is:
A. Endothermic
B. Spontaneous
C. Anabolic
D. Represented by a ∆G > 0
E. More than one of the above
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Questions/Discussion
Which of the following regarding competitive inhibitors is true?
A. A competitive inhibitor will have the same mass as the
substrate
B. It has a structure like that of the substrate.
C. It will help to form the same products downstream as a
substrate.
D. It will bind with the enzyme at an allosteric region.
E. It cannot be overcome with increasing concentration of the
substrate.
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Questions/Discussion
The result of a(n) __________ reaction is that energy is
released. Energy must be added for a(n) __________ reaction
to proceed.
A. Enzyme catalyzed, non-spontaneous
B. Exergonic, endergonic
C. Endergonic, spontaneous
D. Catalytic, non-catalytic
E. Oxidative, hydrolysis:
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Questions/Discussion
Viagra (sildenafil) is a drug that increases blood flow by relaxing
smooth muscle cells that surround blood vessels. Sildenafil does
this by maintaining elevated cGMP levels by inhibiting the enzyme
phosphodiesterase. Let's say for one specific phosphodiesterase,
sildenafil binds to that phosphodiesterase in such a way that cGMP
cannot bind to that active site. What type of regulator is Viagra?
A. Noncompetitive Inhibitor
B. Allosteric activator
C. Allosteric inhibitor
D. Competitive inhibitor
E. More than one of the above is correct
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Questions/Discussion
Which of the following regarding enzymes is false?
A. An enzyme that requires a cofactor will not produce any downstream
product formation if there is no cofactor present.
B. An enzyme that requires a cofactor, that’s lacking the cofactor, will
produce the same amount of product formation as the same reaction
without the enzyme present.
C. Enzymes that require cofactors will produce products if they have their
cofactor, even if they don’t have substrate present.
D. Enzymes that have multiple catalytic subunits can be regulated
allosterically by 1 of the active sites.
E. Enzymes that only have 1 active site are incapable of cooperativity.
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Questions/Discussion
Vioxx and other prescription nonsteroidal anti-inflammatory
drugs (NSAIDs) are potent inhibitors of the cyclooxygenase-2
(COX-2) enzyme. High substrate concentrations reduce the
efficacy of inhibition by these drugs. These drugs are
A. Noncompetitive inhibitors.
B. Allosteric regulators.
C. Prosthetic groups.
D. Competitive inhibitors.
E. Feedback inhibitors.
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Questions/Discussion
A reaction has a ∆G of –5.6 kcal/mol. Which of the following would
most likely be true
A. The reaction could be coupled to power an endergonic reaction
with a ∆G of +8.8 kcal/mol.
B. The reaction is nonspontaneous.
C. To take place, the reaction would need to couple to ATP
hydrolysis.
D. The reaction would result in products with a greater free-energy
content than in the initial reactants.
E. The reaction would proceed by itself but might be very slow
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Which statement accurately describes enzyme regulation?
A. Competitive inhibition is irreversible while noncompetitive
inhibition is reversible.
B. Noncompetitive inhibition can be overcome by increasing
substrate concentration.
C. Noncompetitive inhibition mimics the size, shape, and charge of
the substrate when binding to an allosteric site.
D. In the cooperative binding model, an enzyme has a lower affinity
for the substrate when there are lower concentrations of it.
E. More than one choice above is correct.
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Questions/Discussion
(+) Cooperativity
Reaction Rate
[S[ conc.
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Questions/Discussion
Which of the following is accurate regarding the following
redox reaction?
A. Y is becoming oxidized
B. X is a reducing agent
C. Y is the reducing agent
D. X is becoming reduced
E. None of the above
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Questions/Discussion
Which of the following is accurate regarding the following
redox reaction?
A. Cl is becoming oxidized
B. Na is a reducing agent
C. Cl is the reducing agent
D. Na is becoming reduced
E. None of the above
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Questions/Discussion
Which of the following is accurate regarding the following
redox reaction?
A. Alcohol is becoming oxidized
B. NAD+ is a reducing agent
C. Alcohol is the reducing agent
D. NAD+ is becoming reduced
E. None of the above
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Questions/Discussion
Which of the following regarding NADH is false?
A. NADH is a coenzyme
B. NAD+ can act as an electron carrier
C. NAD+ is the reduced form
D. NAD+ can accept two electrons and a proton
E. NAD+ is organic
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Questions/Discussion
Which two statements accurately describe glycolysis?
A. NADH is reduced; CO2 is produced.
B. NAD+ is reduced; 2 total ATP are formed
C. NADH is oxidized; 4 net ATP are formed
D. NAD+ is reduced; no CO2 is produced.
E. More than of the above are correct.
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Exit Quiz (8:30-9:20 class)
1. What type of enzyme is this?
2. In one sentence or less, what is one difference between
competitive inhibitor and non-competitive inhibitor
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Exit Quiz (9:30-10:20 class)
1. What type of enzyme
is this?
2. In one sentence or less, what is one difference between
anabolic and catabolic reactions in regard to free energy?
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Questions/Discussion
Which statement accurately describes enzyme regulation?
A. Competitive inhibition is irreversible while noncompetitive
inhibition is reversible.
B. Noncompetitive inhibition can be overcome by increasing
substrate concentration.
C. Noncompetitive inhibition mimics the size, shape, and charge of
the substrate when binding to an allosteric site.
D. In the cooperative binding model, an enzyme has a lower affinity
for the substrate when there are lower concentrations of it.
E. More than one choice above is correct.
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Questions/Discussion
Which of the following is accurate regarding the following
redox reaction?
A. Y is becoming oxidized
B. X is a reducing agent
C. Y is the reducing agent
D. X is becoming reduced
E. None of the above
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Questions/Discussion
Which of the following is accurate regarding the following
redox reaction?
A. Cl is becoming oxidized
B. Na is a reducing agent
C. Cl is the reducing agent
D. Na is becoming reduced
E. None of the above
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Questions/Discussion
Which of the following is accurate regarding the following
redox reaction?
A. Alcohol is becoming oxidized
B. NAD+ is a reducing agent
C. Alcohol is the reducing agent
D. NAD+ is becoming reduced
E. None of the above
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Questions/Discussion
Which of the following regarding NADH is false?
A. NADH is a coenzyme
B. NAD+ can act as an electron carrier
C. NAD+ is the reduced form
D. NAD+ can accept two electrons and a proton
E. NAD+ is organic
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Which two statements accurately describe glycolysis?
A. NADH is reduced; CO2 is produced.
B. NAD+ is reduced; 2 total ATP are formed
C. NADH is oxidized; 4 net ATP are formed
D. NAD+ is reduced; no CO2 is produced.
E. More than of the above are correct.
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Questions/Discussion
Which enzyme first starts glycolysis in the liver?
A. Phosphofructokinase-1 (PFK-1)
B. Pyruvate Kinase
C. Triose Phosphate isomerase
D. Glucose-6-phosphatase
E. Glucokinase (hexokinase for other cell types)
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What is the net number of ADP and NAD+ molecules made in
glycolysis when there’s 4 glucose molecules?
A. 6, 6
B. 4, 8
C. 8, 8
D. 10, 10
E. None of the above
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Questions/Discussion
How many FADH2’s are totally produced throughout all cellular
respiration if there was 100 glucose molecules?
A. 1
B. 10
C. 100
D. 200
E. 300
NOTE: 4 FADH2’s used in ETC, this question is wrong
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Questions/Discussion
The process of cellular respiration is ___________, and during
it, glucose is _____________, while oxygen is ___________?
A. Endergonic, reduced, reduced
B. Exergonic, reduced, reduced
C. Exergonic, reduced, oxidized
D. Exergonic, oxidized, reduced
E. Exergonic, oxidized, oxidized
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Questions/Discussion
Which of the following statements are FALSE?
A. Pyruvate kinase catalyzing PEP to pyruvate is irreversible
B. ATP inhibits PFK-1
C. ADP/AMP inhibits PFK-1
D. Citrate will inhibit PFK-1
E. PFK-1 step is consider irreversible in nature because it’s
largely exergonic
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Questions/Discussion
Which of the following is not an immediate net product of the
typical mitochondrial electron transport chain?
A. ATP
B. Water
C. NAD+
D. FAD
E. a proton electrochemical gradient
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What would create the most ATP through its breakdown and
use through cellular respiration?
A. A molecule of glucose
B. A triglyceride
C. A nucleotide
D. An amino acid
E. Not enough information.
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Questions/Discussion
Cellular respiration breaks down glucose and releases carbon
dioxide and water. Which steps in the oxidation of pyruvate
produces carbon dioxide?
A. Removal of a carboxyl group from pyruvate releases carbon
dioxide. The pyruvate dehydrogenase complex comes into play.
B. Removal of an acetyl group from pyruvate releases carbon
dioxide. The pyruvate decarboxylase complex comes into play.
C. Removal of a carbonyl group from pyruvate releases carbon
dioxide. The pyruvate dehydrogenase complex comes into play.
D. Removal of an acetyl group from pyruvate releases carbon
dioxide. The pyruvate dehydrogenase complex comes into play.
E. None of the above
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