BIOD 171 Module 2 Exam (Version-3, Latest-.
What is cellular metabolism? - (answer)Metabolism is a controlled set of biochemical reactions that
occur in living organisms in order to maintain life
What is the primary function of enzymes, and how are they regulated? - (answer)Enzymes speed up
chemical reactions. Most notably, the enzyme is not consumed during the reaction and can be used
repeatedly by the cell. Enzymes can also be regulated by a cofactor such that in the absence of the
proper cofactor, enzymes are inactive while in its presence enzymes are active.
What is the difference between catabolism and anabolism? - (answer)Catabolism is the process of
breaking down larger molecules into useful energy sources whereas anabolism is the building up or
biosynthesis od macromolecules from smaller molecular units into larger complexes, most often
associated with cellular growth and repair
ATP has the energy to ______, while ADP has the capacity to ______ energy. - (answer)Donate, accept
Chemotrophs can be subdivided into what two additional subgroups? - (answer)Chemotrophs, which
acquire energy from preformed chemicals found in the environment, can be divided into either
organotrophs (removing electrons from organic molecules such as glucose) or lithotrophs, which remove
electrons from inorganic molecules
Chemotrophs utilize which form of phosphorylation? - (answer)Chemotrophs use oxidative
phosphorylation (may also accept substrate level 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? - (answer)Glycolysis is the first step of
this process and yields 2 molecules of ATP. Next, by either fermentation (or respiration) 2 additional
molecules of ATP can be produces. Last, the electron transport chain (ETC) produces 34 ATP via an
oxidative phosphorylation event at the plasma membrane.
What are the reactants of glycolysis? - (answer)Reactants are defined as any molecules present and
involved at the beginning of a specific chemical reaction (ie) glycolysis. In terms of writing out a chemical
reaction, the reactants are everything located to the left of the arrow. The reactants of glycolysis are
glucose, the co-enzyme NAD+ and ATP.
, BIOD 171 Module 2 Exam (Version-3, Latest-.
How are the TCA and ETC related? - (answer)The end products of the Kreb's (TCA) cycle are used to fuel
the electron transport chain. In other words, as the Kreb's cycle (TCA) produces an abundance of
reduced electron carriers (NADH and FADH2), it fuels the ETC. As the electrons are transferred from
NADH/FADH2 to terminal electron acceptors a proton motor force is generated, ATP synthase is
activated and up to 34 molecules of ATP can be produced.
In the absence of sugars, are entirely different metabolic pathways used to process alternative sugar
sources (fructose or lactose)? - (answer)No. Additional enzymatic steps are simply required at the
beginning of catabolism to convert complex sugars into usable forms of either glucose or a glucose
intermediate (glucose-6-phosphate)
Proteases are used to catabolize what? - (answer)Proteases are used to breakdown proteins (whereas
lipases are used to breakdown lipids)
Excluding sugars, what are the other sources of energy? Which is highest in energy? -
(answer)Carbohydrates, proteins, and lipids can all serve as potential energy sources in the absence of
sugar. Lipids are rich in energy, often having several reduced carbon molecules (high in hydrogen
content) that can be used in both the TCA and ETC cycles
In what organelle does photosynthesis take place? - (answer)Photosynthesis, the process of capturing
sunlight and converting it into a usable energy source, occurs in the chloroplasts. Chloroplasts are
double-membrane enclosed organelles. Each chloroplast contains the green photosynthetic pigment
chlorophyll.
What are the two main strategies for replenishing cellular concentrations of NAD+, and when are these
strategies utilized? - (answer)Fermentation and respiration are the two strategies used by the cell to
convert NADH (end product of glycolysis) back to NAD+. Fermentation occurs in the absence of oxygen
(anaerobic conditions) while respiration occurs under aerobic (presence of oxygen) conditions. Notably,
respiration is more efficient than fermentation.
In phosphorylation, the light reactions always occur where? - (answer)The process of converting light
energy into chemical energy (photophosphorylation) always occurs in the membrane. Similar to the
electron transport chain, one of its main functions is to generate a proton concentration gradient to
generate ATP.
What is cellular metabolism? - (answer)Metabolism is a controlled set of biochemical reactions that
occur in living organisms in order to maintain life
What is the primary function of enzymes, and how are they regulated? - (answer)Enzymes speed up
chemical reactions. Most notably, the enzyme is not consumed during the reaction and can be used
repeatedly by the cell. Enzymes can also be regulated by a cofactor such that in the absence of the
proper cofactor, enzymes are inactive while in its presence enzymes are active.
What is the difference between catabolism and anabolism? - (answer)Catabolism is the process of
breaking down larger molecules into useful energy sources whereas anabolism is the building up or
biosynthesis od macromolecules from smaller molecular units into larger complexes, most often
associated with cellular growth and repair
ATP has the energy to ______, while ADP has the capacity to ______ energy. - (answer)Donate, accept
Chemotrophs can be subdivided into what two additional subgroups? - (answer)Chemotrophs, which
acquire energy from preformed chemicals found in the environment, can be divided into either
organotrophs (removing electrons from organic molecules such as glucose) or lithotrophs, which remove
electrons from inorganic molecules
Chemotrophs utilize which form of phosphorylation? - (answer)Chemotrophs use oxidative
phosphorylation (may also accept substrate level 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? - (answer)Glycolysis is the first step of
this process and yields 2 molecules of ATP. Next, by either fermentation (or respiration) 2 additional
molecules of ATP can be produces. Last, the electron transport chain (ETC) produces 34 ATP via an
oxidative phosphorylation event at the plasma membrane.
What are the reactants of glycolysis? - (answer)Reactants are defined as any molecules present and
involved at the beginning of a specific chemical reaction (ie) glycolysis. In terms of writing out a chemical
reaction, the reactants are everything located to the left of the arrow. The reactants of glycolysis are
glucose, the co-enzyme NAD+ and ATP.
, BIOD 171 Module 2 Exam (Version-3, Latest-.
How are the TCA and ETC related? - (answer)The end products of the Kreb's (TCA) cycle are used to fuel
the electron transport chain. In other words, as the Kreb's cycle (TCA) produces an abundance of
reduced electron carriers (NADH and FADH2), it fuels the ETC. As the electrons are transferred from
NADH/FADH2 to terminal electron acceptors a proton motor force is generated, ATP synthase is
activated and up to 34 molecules of ATP can be produced.
In the absence of sugars, are entirely different metabolic pathways used to process alternative sugar
sources (fructose or lactose)? - (answer)No. Additional enzymatic steps are simply required at the
beginning of catabolism to convert complex sugars into usable forms of either glucose or a glucose
intermediate (glucose-6-phosphate)
Proteases are used to catabolize what? - (answer)Proteases are used to breakdown proteins (whereas
lipases are used to breakdown lipids)
Excluding sugars, what are the other sources of energy? Which is highest in energy? -
(answer)Carbohydrates, proteins, and lipids can all serve as potential energy sources in the absence of
sugar. Lipids are rich in energy, often having several reduced carbon molecules (high in hydrogen
content) that can be used in both the TCA and ETC cycles
In what organelle does photosynthesis take place? - (answer)Photosynthesis, the process of capturing
sunlight and converting it into a usable energy source, occurs in the chloroplasts. Chloroplasts are
double-membrane enclosed organelles. Each chloroplast contains the green photosynthetic pigment
chlorophyll.
What are the two main strategies for replenishing cellular concentrations of NAD+, and when are these
strategies utilized? - (answer)Fermentation and respiration are the two strategies used by the cell to
convert NADH (end product of glycolysis) back to NAD+. Fermentation occurs in the absence of oxygen
(anaerobic conditions) while respiration occurs under aerobic (presence of oxygen) conditions. Notably,
respiration is more efficient than fermentation.
In phosphorylation, the light reactions always occur where? - (answer)The process of converting light
energy into chemical energy (photophosphorylation) always occurs in the membrane. Similar to the
electron transport chain, one of its main functions is to generate a proton concentration gradient to
generate ATP.
