48 Questions
Which of the following is NOT a level of protein structure?
Octet
What is the term for the disruption in folding or shape of a protein?
Denaturation
Which of the following can cause protein denaturation?
All of the above
What type of bonds within proteins can be disrupted by heavy metal ions?
Ionic binds
Which of the following heavy metals can denature proteins based on charge?
Both mercury and lead
What type of amino acid side chain can heavy metals like mercury and lead bind to?
Charged side chains
Which of the following interactions within a protein would be disrupted by heavy metals?
Sulfhydryl group
Which of the following is NOT a way in which cofactors and coenzymes can help enzymes speed up reactions?
Prevent the formation of enzyme-substrate complexes
What effect does temperature have on enzyme activity?
Increases enzyme activity
Which types of bonds between the enzyme and substrate would potentially be disrupted by a change in pH?
Hydrogen bonds
What is the function of a lysosome?
Main site of intracellular enzymatic degradation
At what pH are lysosomal enzymes active?
pH of ~4.5
What type of enzyme modification alter the structure of an enzyme making or breaking covalent bonds?
Covalent modification
What is the main type of covalent modification that can alter the structure of an enzyme?
Phosphorylation
Which of the following is the basis of lead poisoning?
Binding to sulfhydryl (SH) groups
Enzymes speed up a reaction by lowering the __________ of the reaction.
Activation energy (Ea)
The highest energy configuration formed when changing from reactants to products is called the __________.
Transition state (TS)
Enzymes are highly specific because __________.
They have a special cleft called the active site
Which amino acid side chain can easily function as an acid or a base?
Serine (Ser)
Which nucleophilic side groups can form a temporary covalent bond with the substrate in enzyme active sites?
Serine (Ser) and Cysteine (Cys)
What is the role of magnesium in glycolytic enzymes involving ATP?
To position the ATP in the enzyme active site
Which enzyme catalyzes the phosphorylation in glycogen metabolism?
Glycogen phosphorylase kinase
Which enzyme is inhibited by covalent modification in glycogen metabolism?
Glycogen synthase
What type of modification is involved in irreversible covalent modification of enzymes?
Cleavage of peptide bonds
Which type of modification changes the conformation and activity of the enzyme by binding to its allosteric site?
Allosteric modification
What is the effect of an effector molecule binding to an allosteric enzyme?
Activating or inhibiting binding of the substrate to the enzyme
Which enzyme is allosterically inhibited by high levels of ATP?
Phosphofructokinase-1
Which enzyme is allosterically activated by high levels of AMP?
Phosphofructokinase-1
What is the purpose of compartmentalization of enzymes via membrane-bound organelles?
To create unique microenvironments
At what pH do lysosomal enzymes function?
Around 4.5-5
What is the term for the disruption in folding or shape of a protein?
Denaturation
Which of the following interactions within a protein would be disrupted by heavy metals?
Disulfide bridges
What is the function of a lysosome?
Intracellular digestion
Which amino acid side chain can easily function as an acid or a base?
Histidine
What type of amino acid side chain can heavy metals like mercury and lead bind to?
Basic
At what pH do lysosomal enzymes function?
Acidic
Which of the following is the basis of lead poisoning?
Binding to enzymes and interfering with their function
Which of the following can cause protein denaturation?
All of the above
Which type of protein is generally long and rod-shaped, providing strength and often insoluble in water?
Fibrous Protein
Which type of protein is generally compact and spherical, often soluble in water, and has dynamic functions such as catalyzing reactions?
Globular Protein
Which level of protein structure refers to the linear sequence of amino acids in a protein?
Primary Structure
Which level of protein structure refers to the folding and twisting of the polypeptide chain due to hydrogen bonding between amino acids?
Secondary Structure
Which level of protein structure refers to the overall 3D arrangement of a single polypeptide chain?
Tertiary Structure
Which level of protein structure refers to the arrangement of multiple polypeptide chains in a protein complex?
Quaternary Structure
What is the term for the process of unfolding or disruption in the shape of a protein, resulting in loss of function?
Denaturation
Which type of catalysis involves the transfer of a proton from an acid to a base?
Acid-Base Catalysis
Which type of catalysis involves the formation of a covalent bond between the enzyme and substrate?
Covalent Catalysis
What are small molecules or ions that are required for the proper functioning of some enzymes called?
Cofactors
Test your knowledge on cofactors and coenzymes with this quiz. Learn about their role in speeding up reactions and their ability to accept or donate electrons in redox reactions. Discover how they help position the substrate in the active site and stabilize negative charges for nucleophilic attacks.
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