BISC 261 Microbiology Ch 6 Test with
Questions Solved with 100% Correct
Answers
Ribozymes - Answer Thomas Cech and Sidney Altman discovered that some
RNA molecules also can catalyze reactions
E.g.
-Catalyze peptide bond formation
-Self-splicing
-Involved in self-replication
Regulation of Metabolism - Answer Important for conservation of energy and materials
Maintenance of metabolic balance despite changes in environment
3 major mechanisms:
-Metabolic channeling
-Regulation of the synthesis of a particular enzyme (transcriptional and translational)
-Direct controlling of the activity of enzymes (posttranslational regulation)
Metabolic Channeling - Answer Different localization of enzymes and metabolites
, Compartmentation
-Differential distribution of enzymes and metabolites among separate cell structures
or organelles
-Can generate marked variations in metabolite concentrations
Posttranslational Regulation of enzyme activity - Answer 2 important reversible control
measures:
-Allosteric regulation
-Covalent modification
Allosteric Regulation (reversible) - Answer Most regulatory enzymes
Activity altered by small molecule known as an allosteric effector
What happens when it binds?
-Positive and negative effectors (more or less able to accept the substrate after altered)
Covalent modification of enzymes (reversible) - Answer Reversible on and off switch
-Addition or removal of a chemical group (phosphoryl, methyl, adenylyl)
Advantages of this method?
-Respond to more stimuli in varied/sophisticated ways
Feedback Inhibition - Answer Also called end product inhibition
End product (substrate) prevents an earlier substrate from being synthesized,
which causes all substrates following the earlier substrate from being created
Questions Solved with 100% Correct
Answers
Ribozymes - Answer Thomas Cech and Sidney Altman discovered that some
RNA molecules also can catalyze reactions
E.g.
-Catalyze peptide bond formation
-Self-splicing
-Involved in self-replication
Regulation of Metabolism - Answer Important for conservation of energy and materials
Maintenance of metabolic balance despite changes in environment
3 major mechanisms:
-Metabolic channeling
-Regulation of the synthesis of a particular enzyme (transcriptional and translational)
-Direct controlling of the activity of enzymes (posttranslational regulation)
Metabolic Channeling - Answer Different localization of enzymes and metabolites
, Compartmentation
-Differential distribution of enzymes and metabolites among separate cell structures
or organelles
-Can generate marked variations in metabolite concentrations
Posttranslational Regulation of enzyme activity - Answer 2 important reversible control
measures:
-Allosteric regulation
-Covalent modification
Allosteric Regulation (reversible) - Answer Most regulatory enzymes
Activity altered by small molecule known as an allosteric effector
What happens when it binds?
-Positive and negative effectors (more or less able to accept the substrate after altered)
Covalent modification of enzymes (reversible) - Answer Reversible on and off switch
-Addition or removal of a chemical group (phosphoryl, methyl, adenylyl)
Advantages of this method?
-Respond to more stimuli in varied/sophisticated ways
Feedback Inhibition - Answer Also called end product inhibition
End product (substrate) prevents an earlier substrate from being synthesized,
which causes all substrates following the earlier substrate from being created
