Biochemistry I Final- Lahousse Exam
2026 Questions and Answers
Understand why creating and maintaining order requires work and energy.Gibbs
free energy concepts - Correct answer-Living organisms are highly ordered beings
that must utilize energy in order to do work. The 2nd law of thermodynamics states
that entropy or randomness is always increasing. However, organisms maintain
relatively stable high ordered states. To do this, they have to utilize energy.
What do we mean or understand by "Living organisms exist in a dynamic steady
state, never at equilibrium with their surroundings" - Correct answer-Living
organisms try to maintain homeostasis by living within a narrow range of
conditions. A dynamic steady state describes this state in which the environment
remains relatively constant or is pushed into returning to it's relatively constant
nature. Living organisms body's create unfavorable chemical reactions. Therefore,
the chemical gradients that exist in the surroundings cannot exist in the body.
Non-polar compounds force energetically unfavorable changes in thestructure of
water (hydrophobic effect). How does this concept apply tobiomolecular
structures. - Correct answer-The hydrophobic effect applies to biomelecular
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,structures as it forces them to take on specific shapes to hide the non polar
molecules. When nonpolar molecules enter water, it disrupts the bonds that the
molecules had made with each other. It causes them to create a cage like structure
around the nonpolar molecule. This results in a decrease in entropy. Additionally,
trying to put a nonpolar molecule in an aqueous solution will result in an increase
in enthalpy (requiring more energy from surroundings) as it will break some of the
hydrogen bonds. This helps explain why nonpolar molecules such as lipids make
good membranes
pH vs structure stability and function - Correct answer-The function of a
biomolecule is often dependent on the structure that it will take. pH plays a role in
structure and function of biomolecules as it can cause conformational changes
within the molecule. pH has the ability to break or make new hydrogen bonds
which can result in other weak interaction changes. This also may cause the
formation of new bonds, resulting in a new structure.
pKa>pH - Correct answer-the molecule is in the acidic state
pKa<pH - Correct answer-the molecule is in the basic form
Acid vs. Conjugate Base - Correct answer-HA vs A-
bond between amino acids - Correct answer-peptide bond
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, how are peptide bonds formed - Correct answer-formed via condensation of the H
on the amino group of one amino acid and the OH on the carboxyl group of
another
How are amino acid sequences read - Correct answer-they are read first at the N
terminus (there will be a free amino group) and then they proceed to the C
terminus ( a free carboxylic acid)
isoelectric point - Correct answer-the pH in which the molecule is at a neutral
charge
pI > pH - Correct answer-molecules have a positive charge
pH> pI - Correct answer-the molecule has a negative charge
size exclusion chromatography - Correct answer-relies on porous beads. The large
molecules will sift through the beads and will not interact with the pores. The
smaller molecules will interact with the pores before moving down the column.
The larger molecules will elute first and the smaller molecules will elute last.
ion exchange chromatography - Correct answer--stationary phase is made of either
negatively or positively charged beads (attract & bind compounds that have
opposite charge)
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2026 Questions and Answers
Understand why creating and maintaining order requires work and energy.Gibbs
free energy concepts - Correct answer-Living organisms are highly ordered beings
that must utilize energy in order to do work. The 2nd law of thermodynamics states
that entropy or randomness is always increasing. However, organisms maintain
relatively stable high ordered states. To do this, they have to utilize energy.
What do we mean or understand by "Living organisms exist in a dynamic steady
state, never at equilibrium with their surroundings" - Correct answer-Living
organisms try to maintain homeostasis by living within a narrow range of
conditions. A dynamic steady state describes this state in which the environment
remains relatively constant or is pushed into returning to it's relatively constant
nature. Living organisms body's create unfavorable chemical reactions. Therefore,
the chemical gradients that exist in the surroundings cannot exist in the body.
Non-polar compounds force energetically unfavorable changes in thestructure of
water (hydrophobic effect). How does this concept apply tobiomolecular
structures. - Correct answer-The hydrophobic effect applies to biomelecular
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,structures as it forces them to take on specific shapes to hide the non polar
molecules. When nonpolar molecules enter water, it disrupts the bonds that the
molecules had made with each other. It causes them to create a cage like structure
around the nonpolar molecule. This results in a decrease in entropy. Additionally,
trying to put a nonpolar molecule in an aqueous solution will result in an increase
in enthalpy (requiring more energy from surroundings) as it will break some of the
hydrogen bonds. This helps explain why nonpolar molecules such as lipids make
good membranes
pH vs structure stability and function - Correct answer-The function of a
biomolecule is often dependent on the structure that it will take. pH plays a role in
structure and function of biomolecules as it can cause conformational changes
within the molecule. pH has the ability to break or make new hydrogen bonds
which can result in other weak interaction changes. This also may cause the
formation of new bonds, resulting in a new structure.
pKa>pH - Correct answer-the molecule is in the acidic state
pKa<pH - Correct answer-the molecule is in the basic form
Acid vs. Conjugate Base - Correct answer-HA vs A-
bond between amino acids - Correct answer-peptide bond
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, how are peptide bonds formed - Correct answer-formed via condensation of the H
on the amino group of one amino acid and the OH on the carboxyl group of
another
How are amino acid sequences read - Correct answer-they are read first at the N
terminus (there will be a free amino group) and then they proceed to the C
terminus ( a free carboxylic acid)
isoelectric point - Correct answer-the pH in which the molecule is at a neutral
charge
pI > pH - Correct answer-molecules have a positive charge
pH> pI - Correct answer-the molecule has a negative charge
size exclusion chromatography - Correct answer-relies on porous beads. The large
molecules will sift through the beads and will not interact with the pores. The
smaller molecules will interact with the pores before moving down the column.
The larger molecules will elute first and the smaller molecules will elute last.
ion exchange chromatography - Correct answer--stationary phase is made of either
negatively or positively charged beads (attract & bind compounds that have
opposite charge)
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
