BIOD 171 MODULE 2 EXAM | QUESTIONS AND ANSWERS |
VERIFIED AND WELL DETAILED ANSWERS (3 VERSIONS) |
LATEST EXAM UPDATE
What is cellular metabolism?
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?
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?
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.
Donate, accept
Chemotrophs can be subdivided into what two additional subgroups?
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?
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?
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?
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.
How are the TCA and ETC related?
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)?
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?
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?
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?
, 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?
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?
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 are the byproducts of light reactions used for in dark reactions?
The ATP and NADPH produced via light reactions are used in dark
reactions to convert carbon dioxide and water into organic carbon
compounds as well as useful carbohydrates (a process called carbon
fixation)
What is the chemical reaction for the Calvin cycle?
6 CO2 + 18 ATP + 12 NADPH + 12 H2O --> C6H12O6 + 18 ADP + 12
NADP+
What determines the specificity of an enzyme?
The specificity of an enzyme is heavily influenced by its active site - a
unique chemical structure bound only by select target molecules. The
structure is influenced by the amino acid composition of the protein as this
in turn influences the fold, shape, and 'appearance' of the enzyme. The
active site (and its target protein) can be thought of as a lock-and-key
relationship. The active site provides specificity (like a lock) that only
specific target proteins can bind - much like how only a specific key will fit
into, unlock, and 'activate' a lock
Do catabolic reactions release or consume energy?
VERIFIED AND WELL DETAILED ANSWERS (3 VERSIONS) |
LATEST EXAM UPDATE
What is cellular metabolism?
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?
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?
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.
Donate, accept
Chemotrophs can be subdivided into what two additional subgroups?
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?
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?
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?
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.
How are the TCA and ETC related?
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)?
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?
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?
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?
, 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?
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?
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 are the byproducts of light reactions used for in dark reactions?
The ATP and NADPH produced via light reactions are used in dark
reactions to convert carbon dioxide and water into organic carbon
compounds as well as useful carbohydrates (a process called carbon
fixation)
What is the chemical reaction for the Calvin cycle?
6 CO2 + 18 ATP + 12 NADPH + 12 H2O --> C6H12O6 + 18 ADP + 12
NADP+
What determines the specificity of an enzyme?
The specificity of an enzyme is heavily influenced by its active site - a
unique chemical structure bound only by select target molecules. The
structure is influenced by the amino acid composition of the protein as this
in turn influences the fold, shape, and 'appearance' of the enzyme. The
active site (and its target protein) can be thought of as a lock-and-key
relationship. The active site provides specificity (like a lock) that only
specific target proteins can bind - much like how only a specific key will fit
into, unlock, and 'activate' a lock
Do catabolic reactions release or consume energy?
