BIOD 171 PORTAGE LEARNING EXAM 2 QUESTIONS AND 100%
CORRECT ANSWERS WITH COMPLETE SOLUTIONS
What is cellular metabolism?
Cellular metabolism is a set of biochemical reactions that occur in living organisms to
maintain life.
What is the primary function of enzymes and how are they regulated?
Enzymes speed up chemical reactions and they are regulated by a co factor.
What is the difference between catabolism and anabolism?
Catabolism is the breaking down of larger molecules into energy sources where
anabolism is the building up of macromolecules from smaller molecules.
ATP has the energy to _______ while ADP has the capacity to _________ energy.
ATP has the energy to DONATE while ADP has the capacity to ACCEPT energy.
Chemotrophs can be subdivided into what two subgroups?
Chemotrophs can be divided by organotrophs and lithotrophs.
Organotrophs remove electrons from organic molecules such as glucose.
Lithographs remove electrons from inorganic molecules.
Chemotrophs utilize which form of phosphorylation?
Chemotrophs use oxidative phosphorylation. Oxidative phosphorylation utilizes the
energy released by the chemical oxidation of nutrients to reform ATP.
What are the three distinct stages in the catabolism of glucose?
Glycolsis is the first step and yields 2 molecules of ATP.
Fermentation or respiration, 2 additional molecules of ATP can be produced.
Last, the electron transport chain produces 34 ATP via oxidative phosphorylation event
at the plasma membrane.
What are the reactants of glycolysis?
, The reactants are any molecules present and involved at the beginning of glycolysis.
The reactants of glycolysis are glucose, NAD+ and ATP.
The reactants are everything located at the left of the arrow.
What are two main strategies for replenishing cellular concentrations of NAD+
and when are these strategies utilized?
Fermentation and respiration are the two strategies used by cells to convert NADH back
to NAD+.
Fermentation occurs when there is no oxygen and respiration occurs when there is
oxygen.
Respiration is more efficient than fermentation.
How are the TCA and ETC related?
The end products of TCA (Krebs) are used to fuel the ETC (electron transport chain).
The TCA produces reduced electron carriers and it fuels the ETC.
In the absence of sugars, are entirely different metabolic pathways used to
process alternative sugar sources (fructose or lactose?)
No.
Proteases are used to catabolize what?
Proteases are used to breakdown proteins.
Lipases are used to breakdown lipids.
Excluding sugars, what are the other sources of energy? Which is highest in
energy?
Carbohydrates, proteins and lipids are all sources of energy. Lipids are rich in energy
and can be used in TCA and ETC cycles.
In what organelle does photosynthesis take place?
Photosynthesis takes place in the chloroplast.
CORRECT ANSWERS WITH COMPLETE SOLUTIONS
What is cellular metabolism?
Cellular metabolism is a set of biochemical reactions that occur in living organisms to
maintain life.
What is the primary function of enzymes and how are they regulated?
Enzymes speed up chemical reactions and they are regulated by a co factor.
What is the difference between catabolism and anabolism?
Catabolism is the breaking down of larger molecules into energy sources where
anabolism is the building up of macromolecules from smaller molecules.
ATP has the energy to _______ while ADP has the capacity to _________ energy.
ATP has the energy to DONATE while ADP has the capacity to ACCEPT energy.
Chemotrophs can be subdivided into what two subgroups?
Chemotrophs can be divided by organotrophs and lithotrophs.
Organotrophs remove electrons from organic molecules such as glucose.
Lithographs remove electrons from inorganic molecules.
Chemotrophs utilize which form of phosphorylation?
Chemotrophs use oxidative phosphorylation. Oxidative phosphorylation utilizes the
energy released by the chemical oxidation of nutrients to reform ATP.
What are the three distinct stages in the catabolism of glucose?
Glycolsis is the first step and yields 2 molecules of ATP.
Fermentation or respiration, 2 additional molecules of ATP can be produced.
Last, the electron transport chain produces 34 ATP via oxidative phosphorylation event
at the plasma membrane.
What are the reactants of glycolysis?
, The reactants are any molecules present and involved at the beginning of glycolysis.
The reactants of glycolysis are glucose, NAD+ and ATP.
The reactants are everything located at the left of the arrow.
What are two main strategies for replenishing cellular concentrations of NAD+
and when are these strategies utilized?
Fermentation and respiration are the two strategies used by cells to convert NADH back
to NAD+.
Fermentation occurs when there is no oxygen and respiration occurs when there is
oxygen.
Respiration is more efficient than fermentation.
How are the TCA and ETC related?
The end products of TCA (Krebs) are used to fuel the ETC (electron transport chain).
The TCA produces reduced electron carriers and it fuels the ETC.
In the absence of sugars, are entirely different metabolic pathways used to
process alternative sugar sources (fructose or lactose?)
No.
Proteases are used to catabolize what?
Proteases are used to breakdown proteins.
Lipases are used to breakdown lipids.
Excluding sugars, what are the other sources of energy? Which is highest in
energy?
Carbohydrates, proteins and lipids are all sources of energy. Lipids are rich in energy
and can be used in TCA and ETC cycles.
In what organelle does photosynthesis take place?
Photosynthesis takes place in the chloroplast.
