Physiology Chapter 4
A chemical reaction that requires an input of energy is
endergonic reaction
The first law of Thermodynamics states that
energy can not be destroyed or create, only transformed.
Prostate cancer can lead to difficult with urination due to:
enlarged prostate compresses the urethra
Degree of disorganization is
entropy
Chemical reactions that produce energy is
exergonic
Energy from the environment is broken down in ____ reactions to drive the endergonic reactions in our bodies.
exergonic
Reactions that release energy are called?
exergonic reactions.
An enzyme can only bind one substrate at a time.
false
An enzyme speeds up a chemical reaction in the cell, but can only be used once.
false
It is _______ that most reactions in the body occur without the need for catalysts.
false
a thermodynamic quantity equivalent to the capacity of a system to do work is
free energy
Blood sugar refers to what molecule circulating in blood?
glucose
In endergonic reactions, occur in reactions where the reactants are at a ____ state of entropy and the products are at a ____ state of entropy.
greater, lesser
What condition does Tom's elevated MB isoform of creatine phosphate suggest?
heart attack
the proposition that the rate of a chemical reaction is directly proportional to the product of the activities or concentrations of the reactants is
law of mass action
Products of exergonic will have ____ free energy than the reactants.
lesser
Catalysts ______ the activation energy needed for a reaction to occur.
lower
Catalysts help the reaction occur at?
lower temperatures
Electron Donor
reducing agent
The function of an enzyme is dictated by it's
structure
In a metabolic pathway, the product of one enzyme subsequently becomes the ____ of the next.
substrate
The active site of an enzyme binds to which of the following?
substrate
Enzyme activity can be influenced by
temperature, pH, concentration of cofactors and coenzymes, concentration of enzyme and substrate.
It is ____ that many enzymes are inactive without the presence of cofactors or coenzymes.
true
In the pathway shown, if the product F exhibited allosteric inhibition, then the pathway leading to product F'____ favored.
would be
The figure above shows a series of enzymatic reactions known as a ____ pathway. As in this example, most metabolic pathways are ____ rather than linear. The activities of enzymes at branch points are often regulated by ____ inhibition, where the _____ product of one pathway inhibits the ____ enzyme in that pathway. This inhibition prevents the over production of the product of that pathway and shifts production to the _____ pathway. The mechanism by which the product inhibits the enzyme is known as _____ inhibition. Binding of the inhibitor to the enzyme causes the _____ of the enzyme to change shape so that it can no longer properly bind _____.
metabolic pathway, branching, end product, final, first, alternate, allosteric, active site, substrate.
Cofactors include
metal ions
In endergonic reactions, the ____ contains more free energy than the reactants
more
In a branched metabolic pathway, the product of an intermediate becomes the substrate for _____ enzyme.
more than one
____ metabolic pathways are branched.
most
Universal energy carrier
ATP
Enzymes exhibit peak activity in a ____ pH range called the____. If the pH is not in this range the reaction rate will ____. The pH optimum of an enzyme corresponds to the ____in which it is found. For instance ____has a pH optimum around ____to allow it to work in the extremely ____ gastric juice; whereas trypsin has a pH optimum around ____ to allow it to work in the ____ pH of the pancreatic juice.
narrow, pH-optimum, decrease, body fluid, pepsin, 2, acidic, 9, alkaline.
Where is sucrase found in the human body?
on the microvilli of the small intestine
Enzymes do what?
Increase rate of reaction, don't change the nature of the reaction, lowers activation energy, and are not changed by the reaction (so can be used again)
Adding heat to a reaction does what?
Increases the rate of reactions
Isoenzymes released from damaged tissue include MM, BB, and:
MB
When an atom or molecule lose electrons
Oxidation
What additional test can be done for prostate cancer?
PSA
Electron receiver
oxidation agent
A molecule that loses oxygen is
oxidized
An example of endergonic is
plants need energy from light to turn carbon dioxide and water into glucose.
Enzymes are a subclass of?
proteins
Enzymes are?
proteins
When an atom or molecule gains electrons
Reduction (reduced in charge)
Coenzymes NAD and FAD are found in the vitamin niacin and riboflavin. Why is it that excess amounts of these vitamins are removed from the body in the urine?
They are water soluble vitamins and therefore not stored in the body.
The amount of energy required for a reaction to occur is called the?
activation energy
The energy required for the reactants to engage in a reaction is what?
activation energy
When an enzyme is denatured
an increase in temp will increase the rate of reaction of reactions until the temp reaches a few degrees above the normal body temp
The flow of energy in living systems is
bioenergetics
ATP is able to store and release large amounts of energy because of its:
bond with phosphate groups and its ability to couple to exergonic and endergonic reactions.
End-product inhibition acts on the _____ enzyme.
branch-point
In simple terms sucrase
breaks sucrose into glucose and fructose.
Elevated levels of acid phosphatase in the blood would indicate:
cancer of the prostate
It is false that most reactions in the body occur without the need for?
catalysts
Energy is lost with each transformation as heat, so the available free energy ____?
decreases`
Catalysts _____ the heat of a reaction.
do not change
A molecule that gains a hydrogen is
reduced
