Biochemistry Eam Practice Questions and Answers
Verifies 100% Correct
Of the elements below, two are much more abundant in earth's crust than in living
organisms.
Iron, Silicon are more abundant compared to organisms
A carbon has its electrons stably distributed into sp3 orbitals. How many different
atoms does it likely bond to? (sp2, sp)
4 (3 for sp2 and sp 2)
What is the most appropriate definition on conformation?
The (potentially flexible) spatial arrangement of atoms around fixed bonds in a molecule
What is the most appropriate definition of configuration?
The fixed arrangements of atoms dictated by the bonds of a molecule
You isolate an unusual bacterium that uses sunlight as an energy source but cannot fix
CO2. Instead it breaks down organic molecules from its environment and incorporates
these carbon backbones into new molecules. How would this organism be classified?
Photoheterotroph
What is the meaning of the S term in the equation G=H−TS?
The disorder of the system, the amount of energy that cannot do work
What is the meaning of the G term in the equation G=H−TS?
The amount of energy available to do work in the system
The following reaction:
,S⟶P
has a ΔG of -10 kJ/mol. The reaction is:
Spontaneous
The following reaction:
S⟶P
has a ΔH of -10 kJ/mol, and the product of TΔS is 15 kJ/mol. The reaction is:
Spontaneous (delta g = delta h - T delta S
In the following reaction:
S⟶P
Enthalpy is negative and the product of Temperature and Entropy is positive. What is
the most appropriate description of the spontaneity of the reaction?
Spontaneous
In the following reaction:
S⟶P
Keq=4
If the concentration P, [P], is 10M, and the concentration of S, [S], is 1M, the forward
reaction is:
Nonspontaneous
The Keq of a reaction under standard conditions is equal to 1.
What is the standard free energy of this reaction?
,0
Of the elements below, two are much more abundant in living organisms than in
earth's crust. What are these two elements?
Oxygen, nitrogen
In the following reaction:
S⟶P
Enthalpy is positive and the product of Temperature and Entropy is positive. What is
the most appropriate description of the spontaneity of the reaction?
If enthalpy is positive and the product of Temperature and Entropy is positive, we have
a positive and a negative, which could be positive or negative depending on the
magnitude of the terms. If entropy is positive (as it is), a higher temperature increases
the magnitude of the TΔS term. Thus, as temperature increases this term becomes
larger while ΔH is constant.
Submit
The are the major roles played by lipids? (three)
Energy storage, cellular organization and structure, provision of precursor molecules for
vitamins and hormoes
Are lipids polar and nonpolar?
Nonpolar
What allows for energy storage in lipids?
Long carbon chains
, What makes lipids useful as precursors for signaling molecules?
they can pass through cellular membranes
Describe fatty acids?
building blocks for more complex lipids, they act as fuel for the body and are
components of cell membranes,
Describe the structure of fatty acids?
Long chains of carbons truncated at one end by a carboxylic acid
What is the difference between saturated and unsaturated fatty acids?
Saturated acid only single carbon-carbon bonds, unsaturated contain one or more
carbon-carbon double bonds
Why are fatty acids so energy rich?
Oxidation of fatty acids liberate large amount of chemical energy, the high
concentration of carbon-hydrogen bonds allow them to store more energy in grams
Name some types of fatty acids?
Triacylglyercols, phospholipids, glycolipids are sometimes referred to as fatty acids
Describe the function of triacylglycerols (other wise known as fats and oils)?
Constructed from a three carbon backbone called glycerol, which is attached to three
fatty acid chains
What is the purpose of triacylglycerols?
Store energy, provide thermal insulation and patting
What are adipocytes?
Verifies 100% Correct
Of the elements below, two are much more abundant in earth's crust than in living
organisms.
Iron, Silicon are more abundant compared to organisms
A carbon has its electrons stably distributed into sp3 orbitals. How many different
atoms does it likely bond to? (sp2, sp)
4 (3 for sp2 and sp 2)
What is the most appropriate definition on conformation?
The (potentially flexible) spatial arrangement of atoms around fixed bonds in a molecule
What is the most appropriate definition of configuration?
The fixed arrangements of atoms dictated by the bonds of a molecule
You isolate an unusual bacterium that uses sunlight as an energy source but cannot fix
CO2. Instead it breaks down organic molecules from its environment and incorporates
these carbon backbones into new molecules. How would this organism be classified?
Photoheterotroph
What is the meaning of the S term in the equation G=H−TS?
The disorder of the system, the amount of energy that cannot do work
What is the meaning of the G term in the equation G=H−TS?
The amount of energy available to do work in the system
The following reaction:
,S⟶P
has a ΔG of -10 kJ/mol. The reaction is:
Spontaneous
The following reaction:
S⟶P
has a ΔH of -10 kJ/mol, and the product of TΔS is 15 kJ/mol. The reaction is:
Spontaneous (delta g = delta h - T delta S
In the following reaction:
S⟶P
Enthalpy is negative and the product of Temperature and Entropy is positive. What is
the most appropriate description of the spontaneity of the reaction?
Spontaneous
In the following reaction:
S⟶P
Keq=4
If the concentration P, [P], is 10M, and the concentration of S, [S], is 1M, the forward
reaction is:
Nonspontaneous
The Keq of a reaction under standard conditions is equal to 1.
What is the standard free energy of this reaction?
,0
Of the elements below, two are much more abundant in living organisms than in
earth's crust. What are these two elements?
Oxygen, nitrogen
In the following reaction:
S⟶P
Enthalpy is positive and the product of Temperature and Entropy is positive. What is
the most appropriate description of the spontaneity of the reaction?
If enthalpy is positive and the product of Temperature and Entropy is positive, we have
a positive and a negative, which could be positive or negative depending on the
magnitude of the terms. If entropy is positive (as it is), a higher temperature increases
the magnitude of the TΔS term. Thus, as temperature increases this term becomes
larger while ΔH is constant.
Submit
The are the major roles played by lipids? (three)
Energy storage, cellular organization and structure, provision of precursor molecules for
vitamins and hormoes
Are lipids polar and nonpolar?
Nonpolar
What allows for energy storage in lipids?
Long carbon chains
, What makes lipids useful as precursors for signaling molecules?
they can pass through cellular membranes
Describe fatty acids?
building blocks for more complex lipids, they act as fuel for the body and are
components of cell membranes,
Describe the structure of fatty acids?
Long chains of carbons truncated at one end by a carboxylic acid
What is the difference between saturated and unsaturated fatty acids?
Saturated acid only single carbon-carbon bonds, unsaturated contain one or more
carbon-carbon double bonds
Why are fatty acids so energy rich?
Oxidation of fatty acids liberate large amount of chemical energy, the high
concentration of carbon-hydrogen bonds allow them to store more energy in grams
Name some types of fatty acids?
Triacylglyercols, phospholipids, glycolipids are sometimes referred to as fatty acids
Describe the function of triacylglycerols (other wise known as fats and oils)?
Constructed from a three carbon backbone called glycerol, which is attached to three
fatty acid chains
What is the purpose of triacylglycerols?
Store energy, provide thermal insulation and patting
What are adipocytes?
