What are the six most common elements present as covalent components of
bioorganic compounds? - ANSWER H, O, N, C, S, P, Cl
What are covalent bonds, and how strong and permanent are they relative to
other bonds in living organisms? - ANSWER Covalent bonds are the sharing
of electrons between two species. Non-polar covalent bonds are the strongest
What is the difference between polar and nonpolar covalent bonds? What
combinations of atoms are involved in these two kinds of covalent bonds? -
ANSWER Polar covalent bonds: The EN differs (C-O bonds)
Non-polar covalent bonds: En is identical or is very similar (H-H bonds)
What are common ionic elements in biological systems? What happens to ionic
substances in the aqueous environment of living organisms? What are the
properties of the ionic bonds that occur between inorganic ions or between
organic ions? - ANSWER Common ionic elements: Na and Cl
In aqueous environments, ionic substances dissociate
Inorganic compounds form ionic bonds that have high melting points that are
made up of a single element or compound that does not include carbon or
hydrogen.
What are hydrogen bonds? What organic structures are involved in hydrogen
bonding? What is the importance of hydrogen bonding in living organisms? -
ANSWER Hydrogen bonds are polar bonds that have a partially positive H
interacting with a partially negative element (like O or N). Important because
they are essential for protein structure, binding of enzymes to substrate and they
hold the DNA helixx together.
What are two types of nonpolar bonds? Why do nonpolar molecules aggregate
together in water? - ANSWER Van der waals forces and hydrophobic
interactions
Van der Waals forcesCaused by induced electrical interactions between closely
approaching atoms
,E clouds fluctuate together to "fit together"
Strength depends on size of atoms and the distance
Bigger e- clouds from stronger interactions
Strength is inversely proportional to the 6th power of distance
Atoms need to be 2nm apart
Hydrophobic Interactions
These bonds form due to exclusion of water from groups of non polar molecules
Water molecules prefer each other (strongest interactions)
Forces nonpolar molecules together
Hydrophobic molecules are not really attracted to each other, they just herded
together by water so that the maximum number of water-water interactions can
form
Water molecules push hydrophobic molecules together so that fewer water
molecules need to be near hydrophobic molecules, water water H bonding can
be maximized
What is pH and how does it relate to the molarity of hydrogen ions in solution?
- ANSWER pH is the numerical value of -log[H+]. It describes the solutions
acidity It is inversely related to the hydrogen ion concentration. So if pH
decreases then H ion increases tenfold.
What is a strong acid? What is the percent dissociation of a strong acid in
water? When a strong acid is present in water, why are the molarity of the
strong acid and the molarity of the hydrogen ion the same? - ANSWER A
strong Acid completely dissociates in water. The concentrations of Hydrogen
ion and acid are equal since it dissociates completely in an aqueous
environment.
What is a weak acid, and why are weak acids not completely dissociated? Why
are the molarity of the weak acid and the molarity of the hydrogen ion not the
same? If a 0.1 M solution of a weak acid is 10% dissociated, what is the
molarity of hydrogen ions? - ANSWER Weak Acid does not dissociate
completely in water. Molarities are not the same due to the lack of complete
dissociation.
0.1M x (10/100)= 0.01 M
What is a buffer solution? Why is a mixture of a weak acid and its conjugate
base needed to give good buffering? Why doesn't a solution containing just a
, weak acid serve as a buffer? Why don't strong acids serve as buffers? -
ANSWER A buffer solution consists of a weak acid and its conjugate base
equilibrium in an aqueous solvent. It can resist changes in pH when a strong
acid or strong base is added. Can't have just one because then the equation
would only go one way. A strong acid can't be a buffer because it ionizes
completely.
Write the Henderson-Hasselbach equation. What are the definitions of pH, pKa
and log A-/HA? Why do all weak acids give the same shaped titration curve? At
what pH does a weak acid and conjugate base combination give the best
buffering? If a weak acid has a pKa of 5 what is the pHwhen the weak acid is
10%, 50% and 90% titrated with NaOH? - ANSWER pH=pKA+log[A-]/[HA].
pH describes the solution acidity as it is the numerical value of -log[H+].pKa is
the strength of an acid. Log a-/HA is the molar concentration of the conjugate
base. All have the same titration curve because it has the same flat region +/- 1
unit from pKa, give the best buffering at pH that is -/+1 from pKa
PH=4.05, 5, 5.95
If the pKa is 6 and the ratio of A-/HA is 1 what is the pH? If the pKa is 6 and
the ratio of A-/HA is 10 what is the pH? If the pKa is 6 and the pH is 6 what is
the ratio of A-/HA? If the pKa is 6 and the pH is 5 what is the ratio A-/HA? -
ANSWER 6,7,1,0.01
What are the most common oxidation and reduction reactions in living
organisms? - ANSWER The most common oxidation and reduction reactions
in living organism are metabolism reactions
Starting with methane and ending with carbon dioxide, what are the
intermediates in an oxidation pathway in which additional bonds to oxygen are
added at each stage? - ANSWER Alkane ---> Alcohol ---> Aldehyde/Ketone --
-> Carboxylic Acid ---> Carbon Dioxide
Intermediate = NAD+ reduced to NADH with MDH
Starting with ethane and ending with ethyne (aka acetylene) what are the stages
of oxidation in which hydrogen is removed but oxygen is not added to the
compound? - ANSWER Ethane
Oxidation takes 2e- and 2H to make ethene
Oxidation takes 2e- and 2H to make Ethyne
bioorganic compounds? - ANSWER H, O, N, C, S, P, Cl
What are covalent bonds, and how strong and permanent are they relative to
other bonds in living organisms? - ANSWER Covalent bonds are the sharing
of electrons between two species. Non-polar covalent bonds are the strongest
What is the difference between polar and nonpolar covalent bonds? What
combinations of atoms are involved in these two kinds of covalent bonds? -
ANSWER Polar covalent bonds: The EN differs (C-O bonds)
Non-polar covalent bonds: En is identical or is very similar (H-H bonds)
What are common ionic elements in biological systems? What happens to ionic
substances in the aqueous environment of living organisms? What are the
properties of the ionic bonds that occur between inorganic ions or between
organic ions? - ANSWER Common ionic elements: Na and Cl
In aqueous environments, ionic substances dissociate
Inorganic compounds form ionic bonds that have high melting points that are
made up of a single element or compound that does not include carbon or
hydrogen.
What are hydrogen bonds? What organic structures are involved in hydrogen
bonding? What is the importance of hydrogen bonding in living organisms? -
ANSWER Hydrogen bonds are polar bonds that have a partially positive H
interacting with a partially negative element (like O or N). Important because
they are essential for protein structure, binding of enzymes to substrate and they
hold the DNA helixx together.
What are two types of nonpolar bonds? Why do nonpolar molecules aggregate
together in water? - ANSWER Van der waals forces and hydrophobic
interactions
Van der Waals forcesCaused by induced electrical interactions between closely
approaching atoms
,E clouds fluctuate together to "fit together"
Strength depends on size of atoms and the distance
Bigger e- clouds from stronger interactions
Strength is inversely proportional to the 6th power of distance
Atoms need to be 2nm apart
Hydrophobic Interactions
These bonds form due to exclusion of water from groups of non polar molecules
Water molecules prefer each other (strongest interactions)
Forces nonpolar molecules together
Hydrophobic molecules are not really attracted to each other, they just herded
together by water so that the maximum number of water-water interactions can
form
Water molecules push hydrophobic molecules together so that fewer water
molecules need to be near hydrophobic molecules, water water H bonding can
be maximized
What is pH and how does it relate to the molarity of hydrogen ions in solution?
- ANSWER pH is the numerical value of -log[H+]. It describes the solutions
acidity It is inversely related to the hydrogen ion concentration. So if pH
decreases then H ion increases tenfold.
What is a strong acid? What is the percent dissociation of a strong acid in
water? When a strong acid is present in water, why are the molarity of the
strong acid and the molarity of the hydrogen ion the same? - ANSWER A
strong Acid completely dissociates in water. The concentrations of Hydrogen
ion and acid are equal since it dissociates completely in an aqueous
environment.
What is a weak acid, and why are weak acids not completely dissociated? Why
are the molarity of the weak acid and the molarity of the hydrogen ion not the
same? If a 0.1 M solution of a weak acid is 10% dissociated, what is the
molarity of hydrogen ions? - ANSWER Weak Acid does not dissociate
completely in water. Molarities are not the same due to the lack of complete
dissociation.
0.1M x (10/100)= 0.01 M
What is a buffer solution? Why is a mixture of a weak acid and its conjugate
base needed to give good buffering? Why doesn't a solution containing just a
, weak acid serve as a buffer? Why don't strong acids serve as buffers? -
ANSWER A buffer solution consists of a weak acid and its conjugate base
equilibrium in an aqueous solvent. It can resist changes in pH when a strong
acid or strong base is added. Can't have just one because then the equation
would only go one way. A strong acid can't be a buffer because it ionizes
completely.
Write the Henderson-Hasselbach equation. What are the definitions of pH, pKa
and log A-/HA? Why do all weak acids give the same shaped titration curve? At
what pH does a weak acid and conjugate base combination give the best
buffering? If a weak acid has a pKa of 5 what is the pHwhen the weak acid is
10%, 50% and 90% titrated with NaOH? - ANSWER pH=pKA+log[A-]/[HA].
pH describes the solution acidity as it is the numerical value of -log[H+].pKa is
the strength of an acid. Log a-/HA is the molar concentration of the conjugate
base. All have the same titration curve because it has the same flat region +/- 1
unit from pKa, give the best buffering at pH that is -/+1 from pKa
PH=4.05, 5, 5.95
If the pKa is 6 and the ratio of A-/HA is 1 what is the pH? If the pKa is 6 and
the ratio of A-/HA is 10 what is the pH? If the pKa is 6 and the pH is 6 what is
the ratio of A-/HA? If the pKa is 6 and the pH is 5 what is the ratio A-/HA? -
ANSWER 6,7,1,0.01
What are the most common oxidation and reduction reactions in living
organisms? - ANSWER The most common oxidation and reduction reactions
in living organism are metabolism reactions
Starting with methane and ending with carbon dioxide, what are the
intermediates in an oxidation pathway in which additional bonds to oxygen are
added at each stage? - ANSWER Alkane ---> Alcohol ---> Aldehyde/Ketone --
-> Carboxylic Acid ---> Carbon Dioxide
Intermediate = NAD+ reduced to NADH with MDH
Starting with ethane and ending with ethyne (aka acetylene) what are the stages
of oxidation in which hydrogen is removed but oxygen is not added to the
compound? - ANSWER Ethane
Oxidation takes 2e- and 2H to make ethene
Oxidation takes 2e- and 2H to make Ethyne
