WorksheetsProteins, Energy, & Enzymes
Total questions: 72
Worksheet time: 40mins
What are the two general forms in which energy exists?
Chemical energy and potential energy
Kinetic energy and chemical energy
Kinetic energy and potential energy
Energy associated with movement is
kinetic energy
potential energy
chemical potential energy
all of the above
____________ energy is stored energy
chemical potential
potential
kinetic
Chemical energy is a form of ________ energy stored in chemical bonds.
kinetic
potential
What are the two main factors that determine the outcome of a chemical reaction in a living cell?
Rate & Direction
Rate
Direction
Products
2 Law of Thermodynamics states
Energy CANNOT change from one state to another
Energy CAN be created or destroyed
Energy CAN change from one state to another
Energy CANNOT be created or destroyed
1st Law of Thermodynamics states
Energy CANNOT be created or destroyed
Energy CAN be created or destroyed
Energy CAN change from one state to another
Energy CANNOT change from one state to another
When a physical system becomes more disorder, the entropy increases.
True
False
A reaction that releases free energy during product formation is termed a(n) ________ reaction
endergonic
exergonic
non-spontaneous
Adenosine Triphosphate is a common energy source for living organisms?
True
False
ΔG > 0
exergonic reaction
endergonic reaction
ΔG < 0
exergonic
endergonic
Spontaneous or exergonic reactions, which release free energy have negative free-energy charge
True
False
Which of the following describes the hydrolysis of ATP?
ATP is formed when a water molecule adds a phosphate group to ADP.
H2O is added to ATP = breakdown to ADP and inorganic phosphate.
H2O is removed from ATP = release of ADP and inorganic phosphate.
When coupled with exergonic reaction, a endergonic reaction will proceed spontaneously if net energy change is negative
true
false
Which of the following statements about endergonic reactions is false?
Endergonic reactions are spontaneous.
Endergonic reactions have a positive change in free energy.
The products have a higher free energy than the reactants.
Endergonic reactions require the addition of free energy.
The hydrolysis of ATP can be used to drive a chemical reaction that cannot occur spontaneously because:
the hydrolysis of ATP is exergonic.
the hydrolysis of ATP has a positive ΔG.
the hydrolysis of ATP requires energy.
the hydrolysis of ATP is endergonic.
The transfer of a phosphate group from one molecule to another is Phosphorylation
True
False
Proteins found in living cells that act as catalysts to speed up chemical reactions are called
RNA Polymerase
Spliceosome
Ribosome
Enzymes
The minimum amount of energy that must be provided for compounds to cause a chemical reaction is called_________ energy
kinetic energy
change in free-energy ( ΔG )
activation energy
potential energy
What happens when the transition state is reached?
The chemical reaction cannot proceed.
A further input of activation energy is required.
Repulsion between the reactants is maximized.
Bonds are stretched to their limit in the reactant molecules.
Enzymes make reactions
slower
faster
no change in rate of reaction
Lowering the activation energy of a chemical reaction will:
change the rate of the reaction but will not change its direction.
cause a non-spontaneous reaction to occur spontaneously.
change the affinity of the substrate for an enzyme.
A chemical reaction can proceed and products can be formed once the _________ state has been achieved
transition
final
How can catalysts increase the rate of chemical reactions?
Catalysts input heat into a system to allow chemical reactions to proceed.
Catalysts can position reactants so they can't interact with each other.
Catalysts can change an endergonic reaction into an exergonic reaction
Catalysts arrange molecules in proper orientation forming covalent bonds
Enzyme-mediated chemical reactions take place when the substrate molecules bind to the ______ ______ of an enzyme.
active site
allosteric site
product site
inhibitor site
How do enzymes lower the activation energy of a chemical reaction?
Enzymes can bring reactants closer together.
Enzymes facilitate chemical reactions by removing excess heat
Lowering the activation energy of a chemical reaction will:
cause a nonspontaneous reaction to occur spontaneously
change the affinity of the substrate for an enzyme.
change the rate of the reaction but will not change its direction.
With the substrate, an enzyme undergoes conformational changes that allows it to bind the substrate more tightly.
tight fit
induced fit
moose fit
loose fit
Generally activation energy is a barrier to the formation of products during a chemical reaction
True
False
In a chemical reaction, an enzyme's ______must change before it can catalyze the conversion of reactants to products
structure
shape
conformation
all of the above
Molecules that bind to an enzyme at the active site and are converted to products in chemical reactions are called
products/reactants
substrates/reactants
Conformational changes does NOT cause enzyme and substrate to bind more tightly to one another
true
false
Metabolic pathways is the general term for all types of coordinated sequences of chemical reaction in cells.
true
false
Oxidation reaction =
loss of e- (electrons)
gain of e- (electrons)
Reduction reaction =
loss of e- (electrons)
gain of e- (electrons)
The removal of electrons from a molecule is called ________ whereas _________ is the addition of electrons to a molecule.
reduction, oxidation
oxidation, reduction
What occurs during a REDOX reaction?
electron is lost from one atom and then gained by another
electron is gained by one atom and then lost by another
Which of the following statements regarding metabolic pathways are true?
Can result in the breakdown of large molecules
The product of one reaction becomes the substrate for the next reaction
Can result in the synthesis of larger molecules from smaller molecules
all of the above
What are differences between reduction and oxidation?
Reduction reduces a molecule's net charge, while oxidation increases it.
Oxidation decreases a molecule's net charge, while reduction increases it.
the _____ ______ blocks the metabolic pathway
feedback inhibitor
regulatory molecule
final product
all of the above
During feedback inhibition, how does binding of the product inhibit enzyme function?
Excess product at allosteric site:
causes shape change preventing binding at active site
prevents substrate from binding because it is in the same site
Each step of a metabolic pathway is catalyzed by a specific enzyme.
true
false
The 20 Amino Acids are categorized into four types based on their chemical properties. What are they?
Hydrophobic, non polar uncharged, Acidic, Basic
Neutral, Polar uncharged, Acidic, Basic
Alkaline, Polar uncharged, Acidic, Basic
Draw an amino acid.
Hint the back bone is N-C-C
Which type of amino acid will form ionic bonds?
Which type of amino acid will for hydrogen bonds?
Which type of amino acid will NOT associate readily with water?
Which amino acid will form disulfide bonds?
Hint: a lot of this is what makes curly hair
The group on the left is a
hydroxyl group
carboxyl group
r group
amino group
The group on the right is the
hydroxyl group
carboxyl group
r group
amino group
How many bonds does Carbon (C) like to form?
Which level of a protein structure is this and what type of bonds hold it together?
Primary structure, peptide bonds
What level of a protein structure is this and what bonds hold it together?
What level of a protein structure is this and what bonds hold it together?
Primary structure,
-ionic bonds
-disulfide bonds
-van der Waal forces
-hydrophobic interactions
-H bonds
Secondary structure,
-ionic bonds
-disulfide bonds
-van der Waal forces
-hydrophobic interactions
-H bonds
Quaternary structure,
-ionic bonds
-disulfide bonds
-van der Waal forces
-hydrophobic interactions
-H bonds
Tertiary structure,
-ionic bonds
-disulfide bonds
-van der Waal forces
-hydrophobic interactions
-H bonds
What level of a protein structure is this and what bonds hold it together?
Primary structure
-ionic bonds
-disulfide bonds
-van der Waal forces
-hydrophobic interactions
-H bonds
Secondary structure
-ionic bonds
-disulfide bonds
-van der Waal forces
-hydrophobic interactions
-H bonds
Tertiary structure
-ionic bonds
-disulfide bonds
-van der Waal forces
-hydrophobic interactions
-H bonds
Quaternary structure
-ionic bonds
-disulfide bonds
-van der Waal forces
-hydrophobic interactions
-H bonds
What is Denaturation?
What causes denaturation?
What type of reaction is A?
endergonic
exergonic
What type of reaction is B?
endergonic
exergonic
What type of reaction is C?
endergonic
exergonic
Why is A endergonic?
ΔG > 0
ΔG < 0
Why is C exergonic?
ΔG > 0
ΔG < 0
What change in free energy is most likely to correspond with A
ΔG = +14.1 kcal/mol
ΔG = -7.3kcal/mol
ΔG = +3.3kcal/mol
Which is most energetically favorable or likely to occur spontaneously?
A
B
C
The exergonic reaction of ______ is often used to fuel ______ reactions.
(a)
An endergonic reaction is also referred to as
anabolic
catabolic
An exergonic reaction is also referred to as
anabolic
catabolic
What is the optimal pH for this enzyme?
6
12
2
8
What happens to this enzyme at the temperature of 60 degrees celsius?
that is the optimal temperature for this enzyme
this enzyme will denature
this enzyme will renature
What is the optimal temperature for this enzyme?
30
80
50
10
We are going to lean more about this in Cellular respiration but for now just know that
(NAD+ and FAD) or reduced forms (NADH and FADH2).
GOOD LUCK MAN!
