week five Flashcards
Define catalyst
substances that increase the rate of chemical reactions without themselves being consumed
Define the rate of a chemical reaction
amount of product formed (or reactant consumed) per unit of time
What are the functions of an enzyme?
-lower the activation energy for the reaction
-increase the rate of a specific reaction
Glyphosate is the active ingredient in the herbicide called ROUND-UP. What common biological molecule does glyphosate resemble?
an amino acid
Glyphosate affects plants because it…
binds to a biosynthetic enzyme and inhibits its activity
Do catalyst affect the equilibrium state of the reaction? Why?
catalysts do not change the equilibrium state of the reaction because they affect both the forward and reverse reactions to the same extent
Catalysts are usually proteins called _____
enzymes
exergonic reactions ______ free energy and endergonic reactions _____ free energy
exergonic reactions release free energy and endergonic reactions require free energy
For an exergonic reaction, the energy _____ is more than the initial input of energy, so there is a ______ of energy.
For an exergonic reaction, the energy released is more than the initial input of energy, so there is a net release of energy.
This intermediate between reactants and products is called the ________
This intermediate between reactants and products is called the transition state
Define the transition state, is it stable, does it require free energy?
intermediate between reactants and products is called the transition state, It is highly unstable and therefore has a large amount of free energy
In all chemical reactions, reactants adopt at least ______ before their conversion into products
In all chemical reactions, reactants adopt at least one transition state before their conversion into products
To reach the transition state what must happen to the reactant?
the reactant must absorb energy from its surroundings
What is activation energy?
all chemical reactions, even spontaneous ones that release energy, require an input of energy that we can think of as an “energy barrier.” The energy input necessary to reach the transition state is called the activation energy
There is an _____ correlation between the rate of a reaction and the height of the energy barrier: the ______ the energy barrier, the _____ the reaction and the ______ the barrier, the ______ the reaction
There is an inverse correlation between the rate of a reaction and the height of the energy barrier: the lower the energy barrier, the faster the reaction and the higher the barrier, the slower the reaction
Although an enzyme ______ the activation energy, the difference in free energy between reactants and products ______
Although an enzyme reduces the activation energy, the difference in free energy between reactants and products does not change
Are catalysts consumed in the chemical process?
no
In a chemical reaction catalyzed by an enzyme, the reactant is often referred to as the ______
substrate
What are the letters that represent substrate, enzyme, and product?
S
E
P
To form an enzyme–substrate complex, enzymes bind substrates at a region of the enzyme called ______
the active site
Many enzymes require additional nonprotein molecules, called ______
Many enzymes require additional nonprotein molecules, called cofactors
Are cofactors organic?
Cofactors can be inorganic or organic
The activity of enzymes is ______ to temperature
The activity of enzymes is also sensitive to temperature. Enzymes have an optimal temperature, which is the temperature at which the enzyme is most active
What happens when an enzyme gets too hot?
At very high temperatures, enzymes unfold, or denature
What happens when an enzyme gets too cold?
At low temperatures, enzyme activity is typically low, as molecules move slowly, or have lower kinetic energy, reducing the probability that the substrate and enzyme will come together and interact with each other
What happens when the pH is too low with enzymes?
most enzymes would be denatured
What is a inhibitor?
decrease the activity of enzymes
What is an activator?
increase the activity of enzymes
What are enzymes that bind at sites other than their active sites
allosteric enzymes
they have a nucleus
they are prokaryotic
they store and follow instruction
their structure is crucial for their function
they interact with the enviorment
they are prokaryotic
C
Please select the properties of life that ALL living things harbor. Select all that apply.
capable of self replication
stores and follows instruction
membrane delimited
are spherical
capable of evolution
responds to the environment
large enough to be seen with the naked eye
stores and uses energy
capable of self replication
stores and follows instruction
membrane delimited
capable of evolution
responds to the environment
stores and uses energy
What trends do elements in the first 3 rows of the periodic table share? Match the statements.
-Atoms in the same row have the same…..
-Atoms in the same column have the same…..
- number of electron shells
- number of valence electrons
An atom has 6 protons. Which if these is NOT true about the atom?
In a neutral state it has 6 electrons
It has 6 neutrons
Its atomic number is 6
It forms 6 bonds
it forms 6 bonds
A C D
True or False? Based on the information in the previous questions on caffeine, caffeine is a hydrophilic molecule.
true
faces: A
avoids: B
The [H+] of a solution changes from .000001 to .000000001? Has the pH increased or decreased or stays the same?
increased
You have a solution with a Hydrogen ion concentration of .00001. The pH of this solution is ______ . This solution is ______ .
You have a solution with a Hydrogen ion concentration of .00001. The pH of this solution is 5 . This solution is acidic .
A solution of pH 5 contains ______________ H+ than the same amount of solution at pH 3. “Fold” is a synonym for “times” or multiplication.
100 fold less
There are 20 different amino acids. What makes one amino acid different from another?
different side chains (R-groups) attached to an α carbon
What element is found in both nucleic acids and all proteins?
nitrogen
Which of the following includes all of the pyrimidines found in nucleic acids?
cytosine, uracil, and thymine
cytosine and thymine
cytosine, uracil, and guanine
cytosine and uracil
adenine and guanine
cytosine, uracil, and thymine
What critical feature of DNA structure allows it to replicate?
complementary bases connected by weak hydrogen bonds
Plants such as the Venus flytrap produce chemical compounds that break down insects into substances that are usable by the plant. The chemical compounds that break down the insects are most likely
lipids
carbohydrates
hydrocarbons
proteins
nucleic acids
proteins
Sucrase is the enzyme that breaks down sucrose (table sugar) into glucose and fructose. Will sucrase also catalyze the breakdown of another disaccharide maltose?
Yes, because enzymes are resuabale
No, because enzymes are very specific for their substrates
No, because enzymes are not recycled and reused
Yes, because an enzyme that breaks one sugar can also break other sugars
No, because enzymes are very specific for their substrates
