DHN 311 COMPREHENSIVE EXAM 2025/2026 QUESTIONS
WITH SOLUTIONS RATED A+
✔✔Epigenetics - ✔✔- The influence of environment/lifestyle (diet), age and disease
conditions on changes in gene expression without changing the DNA sequence ("above
genetics")
- Heritable; can be passed down to next generations
✔✔What are the proteins called that bind to distinct sites on DNA that controls DNA
transcription to RNA? - ✔✔Transcription Factors
✔✔Primary structure bonds - ✔✔- Covalent peptide bonds between amino acids
✔✔Secondary structure bonds - ✔✔- Covalent peptide bonds between amino acids
- Hydrogen bonds
✔✔Tertiary structure bonds - ✔✔-Covalent peptide bonds between amino acids
- Hydrogen bonds
- Disulfide bridges
- Ionic bonds between charged R-groups
- Hydrophobic interactions (hydrophobic R-groups arrange themselves towards the
inside)
✔✔Quaternary structure bonds - ✔✔- Quaternary structure arises from the bonding of
2+ proteins
- Same bonds that are found in tertiary structure
✔✔At which level of protein folding do the side chains (R) interact? - ✔✔Tertiary
✔✔What are the different functions of proteins in the body? - ✔✔- Structure
- Movement
- Transport
- Catalysis
- Hormones
- Protection
- Storage
- Regulation
✔✔A dehydrogenase enzyme indicates which type of reaction is going to take place? -
✔✔A redox reaction
✔✔Non-competitive inhibition - ✔✔- Inhibitor and substrate bind at different sites on the
enzyme
, - The inhibitor can either bind to the free enzyme OR the enzyme-substrate complex to
prevent the reaction from occurring
- Decreases Vmax
- No change in Km
✔✔Competitive Inhibition - ✔✔- Inhibitor binds reversibly to the same site that the
substrate would normally bind and thereby competes with the substrate for that binding
site
- No effect on Vmax
- Increases Km (decreased affinity for the substrate)
✔✔What does having a high or low Km mean for an enzyme? - ✔✔- Low Km = high
affinity for substrate
- High Km = low affinity for substrate
✔✔How do high and low substrate concentrations influence the rate of reaction to form
the Michaelis-Menton curve? - ✔✔- As substrate concentration increases, the rate of
reaction also increases
- The rate will increase until Vmax is reached, and all enzymes are saturated with
enzyme
✔✔What is the purpose of the two sites on an allosteric enzyme? - ✔✔- Allosteric
enzymes function through reversible, noncovalent binding of regulatory compounds
called allosteric modulators
- Catalytic/active site is where the substrate binds
- Regulatory site is where the effector/modulator/regulator binds
✔✔What is the difference between a homotropic and heterotropic enzyme? - ✔✔-
Homotropic: the modulator/effector/regulator is the same molecule as the substrate
- Heterotrophic: the modulator/effector/regulator is a different molecule than the
substrate
✔✔What type of curve do allosteric regulators generate? - ✔✔Sigmoidal curve
✔✔What is cooperativity? - ✔✔- Cooperativity - refers to the observation that binding of
a substance to one binding site increases or decreases the binding to another site
- Binding of a substance affects the affinity of other sites for their substances
✔✔Where is the majority of the NADH/FADH generated that goes to the ETC? -
✔✔Kreb's Cycle
✔✔Which pathway generates CO2? - ✔✔- Kreb's Cycle
- Oxidative pathways
- Glycolysis
WITH SOLUTIONS RATED A+
✔✔Epigenetics - ✔✔- The influence of environment/lifestyle (diet), age and disease
conditions on changes in gene expression without changing the DNA sequence ("above
genetics")
- Heritable; can be passed down to next generations
✔✔What are the proteins called that bind to distinct sites on DNA that controls DNA
transcription to RNA? - ✔✔Transcription Factors
✔✔Primary structure bonds - ✔✔- Covalent peptide bonds between amino acids
✔✔Secondary structure bonds - ✔✔- Covalent peptide bonds between amino acids
- Hydrogen bonds
✔✔Tertiary structure bonds - ✔✔-Covalent peptide bonds between amino acids
- Hydrogen bonds
- Disulfide bridges
- Ionic bonds between charged R-groups
- Hydrophobic interactions (hydrophobic R-groups arrange themselves towards the
inside)
✔✔Quaternary structure bonds - ✔✔- Quaternary structure arises from the bonding of
2+ proteins
- Same bonds that are found in tertiary structure
✔✔At which level of protein folding do the side chains (R) interact? - ✔✔Tertiary
✔✔What are the different functions of proteins in the body? - ✔✔- Structure
- Movement
- Transport
- Catalysis
- Hormones
- Protection
- Storage
- Regulation
✔✔A dehydrogenase enzyme indicates which type of reaction is going to take place? -
✔✔A redox reaction
✔✔Non-competitive inhibition - ✔✔- Inhibitor and substrate bind at different sites on the
enzyme
, - The inhibitor can either bind to the free enzyme OR the enzyme-substrate complex to
prevent the reaction from occurring
- Decreases Vmax
- No change in Km
✔✔Competitive Inhibition - ✔✔- Inhibitor binds reversibly to the same site that the
substrate would normally bind and thereby competes with the substrate for that binding
site
- No effect on Vmax
- Increases Km (decreased affinity for the substrate)
✔✔What does having a high or low Km mean for an enzyme? - ✔✔- Low Km = high
affinity for substrate
- High Km = low affinity for substrate
✔✔How do high and low substrate concentrations influence the rate of reaction to form
the Michaelis-Menton curve? - ✔✔- As substrate concentration increases, the rate of
reaction also increases
- The rate will increase until Vmax is reached, and all enzymes are saturated with
enzyme
✔✔What is the purpose of the two sites on an allosteric enzyme? - ✔✔- Allosteric
enzymes function through reversible, noncovalent binding of regulatory compounds
called allosteric modulators
- Catalytic/active site is where the substrate binds
- Regulatory site is where the effector/modulator/regulator binds
✔✔What is the difference between a homotropic and heterotropic enzyme? - ✔✔-
Homotropic: the modulator/effector/regulator is the same molecule as the substrate
- Heterotrophic: the modulator/effector/regulator is a different molecule than the
substrate
✔✔What type of curve do allosteric regulators generate? - ✔✔Sigmoidal curve
✔✔What is cooperativity? - ✔✔- Cooperativity - refers to the observation that binding of
a substance to one binding site increases or decreases the binding to another site
- Binding of a substance affects the affinity of other sites for their substances
✔✔Where is the majority of the NADH/FADH generated that goes to the ETC? -
✔✔Kreb's Cycle
✔✔Which pathway generates CO2? - ✔✔- Kreb's Cycle
- Oxidative pathways
- Glycolysis
