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If the shape of the enzyme needs to be slightly altered in order to receive the substrate, one would say that this would refer to the _-_ model of enzyme activity.
induced-fit
Enzymatic reactions are dependent on the amount of energy available to run the reaction. True or false
False. Enzymatic reactions are affected by temperature, pH, and the amount of the enzyme, not the amount of energy.
Lipase is an enzyme that has an optimum pH near 2. True or false
False. Lipase is used in the small intestine and works best in a basic environment.
Enzymes secreted from the pancreas to the small intestine are secreted as ___________
zymogens
Coenzymes are derived chemically from ______.
water soluble vitamins
A reaction that would start with a reactant, have a few intermediate steps, and end in a final product would describe a(n) ____________ __________.
metabolic pathway
An enzyme secreted in an inactive form is called a(n) __________
zymogen or proenzyme
End-product inhibition causes ______.
enzyme reactions at one branch point to be reduced in favor of alternate branch products
Allosteric inhibition works because __________________________________________________.
the process causes a change in the shape of the active site, preventing the enzyme from binding further substrates.
An inborn error of metabolism would cause a build up of intermediates ____ the defective enzymatic step.
prior to
Gene therapy was used to treat which disease?
SCID
Which genetic disorder would be a result of an inborn error of metabolism?
PKU
PKU is an example of _____________--
an inborn error of metabolism
If a reaction requires energy to proceed, it is ______.
an endergonic reaction
___________ reactions allow for the exergonic reactions to provide energy required for the endergonic reactions.
Coupled
The conservation of energy is commonly referred to as the ______.
first law of thermodynamics
If a molecule loses electrons during a chemical reaction it is said that molecule has been _________.
oxidized
The molecule that donates electrons in a chemical reaction is the _______ agent while the molecule that gains the electrons is the __________ agent.
reducing, oxidizing
Which atom is the oxidizing agent used at the very end of cellular respiration to receive the final electrons?
Oxygen
During cellular respiration, the hydrogen carriers are ____ and _____.
NAD and FAD
The energy required for endergonic reactions comes from other ______ reactions.
exergonic
What happens to the globin part of hemoglobin that is released from old red blood cells?
broken down into amino acids
What happens to the heme group once the iron is released?
converted to billiverdin and then to bilirubin
What happens to the iron that is released from old red blood cells?
Transported to the liver, red bone marrow, and spleen
How is bilirubin transported to the liver?
Bonded to albumin
What occurs if liver cells are damaged and can not produce the bilirubin derivatives?
Conjugated bilirubin levels increase in the blood, jaundice occurs, and AST and ALT blood levels increase
It is ______ that most reactions in the body occur without the need for catalysts
false
Catalysts _______________ the heat of a reaction.
do not change
Adds water to split molecules
Hydrolase
Removes phosphate groups
Phosphatase
Removes water to join molecules
Synthase
Removes hydrogens
Dehydrogenase
Adds phosphate groups
Kinase
Rearranges the atoms in a molecule
Isomerase
Which type of organic compound are enzymes?
Proteins
The active site is a binding site for which of the following?
Substrate
Where is sucrase found in the human body?
On the microvilli of the small intestine
The function of sucrase is to ________.
break sucrose into glucose and fructose
How does sucrose change the configuration of sucrase?
Sucrose binds to its active site on sucrase, changing the shape of sucrase enzyme.
How often can a sucrase molecule be used to hydrolyze sucrose?
Many times
Elevated levels of acid phosphatase in the blood would indicate ________.
cancer of the prostate
Isoenzymes released from damaged tissue include MM, BB, and ________.
MB
What condition does Tom's elevated MB isoform of creatine phosphate suggest ________.
heart attack
Prostate cancer can lead to difficult with urination due to ________.
enlarged prostate, which compresses the urethra
What additional test can be done for prostate cancer ________.
PSA
where in that disease, the enzyme levels would be abnormal. Alkaline phosphatase
Obstructive jaundice, Paget's disease, and carcinoma of bonemarrow
where in that disease, the enzyme levels would be abnormal. Amylase
Pancreatitis and perforated peptic ulcers
where in that disease, the enzyme levels would be abnormal. Transaminases (ALT/AST)
Hepatitis and muscular dystrophy
It is _______ that many enzymes are inactive without the presence of cofactors or coenzymes.
true
In a metabolic pathway, the product of one enzyme subsequently becomes the ___________ of the next.
substrate
In a branched metabolic pathway, the product of an intermediate becomes the substrate for _________________ enzyme.
more than one
End-product inhibition acts on the _-_ enzyme.
branch-point
ATP is able to store and release large amounts of energy because of its ________.
high energy bond to the third phosphate group and its ability to couple to exergonic and endergonic reactions
Elevated plasma amylase could indicate ________.
pancreatitis
The level of protein structure primarily involved in determining enzyme activity is the ________ enzyme.
tertiary
Biological catalysts ________.
remain unchanged at the end of the reaction
Elevated plasma aldolase could be indicative of muscular dystrophy. What could explain this finding?
When muscle tissue is destroyed, it releases the enzymes present in the muscle cells into the blood.
Addition of phosphate groups to a particular molecule is catalyzed by ________.
kinases
A chemical reaction rate can be increased by either ________ the temperature or ________ the activation energy.
increasing; decreasing
Which of the following occurs when the product of a metabolic pathway binds to an enzyme and decreases enzymatic activity?
Allosteric inhibition
The phosphatase found in bone would have a pH optimum that is ________ than the pH optimum of the phosphatase found in the prostate gland.
higher
Inactive forms of digestive enzymes are called ________.
zymogens
The law of mass action states that ________.
reversible reactions will be driven from the side of higher to lower concentration
Addition of substrate to an already saturated enzyme results in ________ in the rate of the reaction.
no change
Which of the following does NOT affect the activity of an enzyme?
pH and temperature
Concentration of enzyme and substrate molecules
The organ the enzyme is inCorrect
Concentration of cofactors and coenzymes
The organ the enzyme is in
Energy transformations result in ________ in entropy.
an increase
The ________ is the amount of heat required to raise the temperature of one cubic centimeter of water one degree on the Celsius scale.
calorie
Chemically reduced FAD has ________ extra hydrogen atom(s) bound to it.
two
Free energy is ________ when exergonic reactions proceed.
decreased
Which of the following is NOT true of catalysts? They are unchanged by the reaction catalyzed. They allow endergonic reactions to become exergonic reactions.Correct They increase the amount of energy released by a chemical reaction. They lower the activation energy of the reaction.
They allow endergonic reactions to become exergonic reactions.
NAD is derived from the vitamin ________.
B-3, niacin
During reduction, a molecule or atom ________.
gains protons or gains electrons
Catalysts ________ the activation energy of the reaction. Activation energy is the energy required for the _________ to engage in the reaction.
lower, reactants
When a substrate binds to the active site of an enzyme, it forms _______________ bonds, weakening the original bonds of the substrate and allowing them to break easily.
temporary
_: remove phosphate groups _: catalyze dehydration synthesis _______________: promote hydrolysis
Phosphatases Synthetases Hydrolases
_: remove hydrogen atoms _: add phosphate groups __________: rearrange the atoms
Dehydrogenases Kinases Isomerases
_________ are metal ions that help form the active site through a conformational change of the enzyme or help in enzyme-substrate binding
Cofactors (can be within the active site or on the bottom as well)
____________ are organic molecules derived from water-soluble vitamins such as niacin and riboflavin and transport _________ atoms and other small molecules between enzymes.
Coenzymes, hydrogen
What is the inactive form of enzymes called that can be activated when needed?
Zymogen
What is the law of mass action?
When one side gets higher, the other reaction reverses (high to low, low to high)
Few metabolic pathways are _______
linear
What is allosteric inhibition?
The product binds to the enzyme at a location away from the active site and changes the 3D conformation of the enzyme and occurs at an earlier step in the pathway
Inborn errors of metabolism occur when there is a ________ in a single gene that codes for an enzyme in a metabolic pathway
mutation
____________ is the flow of energy in living systems. First Law of Thermodynamics?
Bioenergetics Energy cannot be destroyed or created, only transformed
What is the second law of thermodynamics?
Energy is lost with each transformation as heat, so the available free energy (energy available to do work) decreases
What is endergonic and exergonic reactions?
Endergonic: require an input of energy
Exergonic: produce energy
More organized -> ______ energy -> _____ entropy
more, less
Energy from the environment (food) is broken down in ____________ reactions to drive the _________ reactions in our bodies.
The production of ATP is actually an endergonic reaction that is ______ to an exergonic reaction to drive it.
exergonic, endergonic
coupled
What is reduction and oxidation?
Reduction agent: electron ________ Oxidizing agent: electron _________
Reduction: gains electrons Oxidation: loses electrons
OILRIG
donor receiver
Hydrogen Carrier Molecules NAD = comes from the vitamin ________ (B_) FAD = comes from the vitamin _________ (B__)
Each FAD can accept __ electrons and bind to ___ protons.
Each NAD can accept ___ electrons and bind to __ proton.
niacin (B3) riboflavin (B2) 2, 2 2, 1
What is the reduced form of NAD and FAD?
NADH + H+
FADH2
Note
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