Smartbook CH. 8 Flashcards
ffacillThe term “metabolism” includes which type(s) of cellular reactions?
Both anabolic and catabolic
Enzymes serve as catalysts for:
anabolic and catabolic reactions
Which best describes the function of enzymes?
Facilitate metabolic pathways
Which of the following macromolecules can commonly act as a catalyst?
proteins
The minimum amount of energy required for a reaction to proceed is termed the energy of
activation; energy of activation
The combination of all reactions (catabolic + anabolic) within a cell is termed
metabolism
Enzymes are typically ____ than substrates.
larger
______ act as catalysts in virtually all metabolic pathways.
enzymes
Most enzymes are a functional type of ______ (a type of macromolecule).
protein
What term refers to a biological catalyst that lacks an essential cofactor?
Apoenzyme
An enzyme acts as a biological ______ that alters the rate of a reaction without being changed by the reaction.
catalyst
For an apoenzyme to become a functional holoenzyme, it must ______.
bind to a cofactor
What term is used to describe the minimum amount of energy required for a reaction to proceed?
Activation energy
Which of the following is needed for an apoenzyme to be fully functional?
Cofactor
Substrates are generally ______ than the enzymes to which they bind.
smaller
Which aspect of an enzyme’s structure gives rise to the specificity for its substrate?
Folding to produce a 3-D structure
Which feature of an enzyme is the “most” unique?
Active site
A non-functional enzyme which needs a cofactor is called a(n)
apoenzyme
An enzyme with its apoenzyme and cofactors is referred to as a(n) _____ , or a conjugated enzyme.
holoenzyme
Enzymes are named and classified according to their
Site of action
Type of action
Substrate
is an organic molecule or inorganic element that may be required for an enzyme to become functional.
cofactor
Protein folding determines the 3-D shape in enzymes needed for their ______ for a particular substrate.
specificity
An enzyme’s ______ site is unique for each substrate.
active
What term is used to describe enzymes which work outside the cell?
Exoenzymes
Most enzymes are named to reflect which of the following?
action of the enzyme
describes any enzyme that works within a cell in which it was produced.
endoenzyme
needed for optimal function of an enzyme?
Temperature, pressure, and pH can cause the loss of a protein’s native conformation.
Labile means which of the following?
Chemically unstable
What term is used to describe proteins losing their three dimensional structure as a consequence of changes in the environmental conditions such as excessive heat or salt?
Denaturation
Changes in environmental conditions can cause the denaturation of cellular enzymes, resulting in blocks to metabolic reactions and ultimately in cell death.
true
Typically, each reaction (step) in a metabolic pathway will require
one enzyme
Which of the following can result in the denaturation of enzymes?
High temperatures
Changes in pH
Chemicals
Compounds are called ______ when they can be easily denatured, distorted and/or degraded by mild changes to the environment.
labile
The product of one reaction may act as the ______ for the next reaction in a metabolic pathway.
substrate, reactant, or precursor
The loss of the normal or native shape of a protein due to chemical or physical disruption of tertiary structure is called protein ______.
denaturation
In ______ inhibition, a molecule occupies the active site which prohibits the substrate from binding and therefore, inhibits the enzyme’s activity on the substrate.
competitive, competitive inhibition
If internal cellular enzymes are denatured, it can lead to:
cell death
______ enzyme inhibition is a mechanism of regulation where the active site is blocked by a molecule that resembles the true substrate.
Competitive
Each reaction in a metabolic pathway is catalyzed by a separate ______
enzyme
Negative feedback is a process that ______ enzyme activity when a certain concentration of ______ is produced.
decreases; product
Which is NOT a physical condition needed for optimal function of an enzyme?
Substrate concentration
In ______ enzyme inhibition, a regulatory molecule binds to a site other than the active site.
noncompetitive, feedback, or allosteric
All living cells require a constant input and expenditure of usable
energy
Competitive inhibition decreases the activity of an enzyme by
Blocking the active site of the enzyme
Preventing the enzyme-substrate interaction
Competitive inhibition decreases the activity of an enzyme by
Blocking the active site of the enzyme
Preventing the enzyme-substrate interaction
Inhibitors that share binding affinity with the substrate is termed a ______ inhibitor.
competitive
Energy management in a cell most often involves the making or breaking of chemical ______ and the transfer of ______ from one molecule to another.
bonds, electrons
A mechanism that can slow down enzymatic activity once a certain concentration of product is produced is called
negative feedback
Collective reactions which transfer hydrogens/electrons from one compound to another are termed
redox reactions
An inhibitor which binds to a site other than the active site and controls enzyme activity is called a ____ inhibitor.
noncompetitive
Oxidation reactions are coupled with ______ reactions.
reduction
All cells need a constant input and expenditure of ________ in a usable form.
energy
Which is NOT a common cellular coenzyme that carries electrons?
ADP
In ______ inhibition, a molecule occupies the active site which prohibits the substrate from binding and therefore, inhibits the enzyme’s activity on the substrate.
competitive
Which of the following couples (links) anabolic reactions with catabolic reactions?
ATP
Ways that cells manage the energy needed for metabolic reactions?
Making and breaking chemical bonds
Transferring electrons
In ATP there are ____ phosphate groups?
3 phosphate groups
AMP has how many phosphate groups? (Mono = 1)
1 phosphate group
ADP has how many phosphate groups? (Di = 2)
2 phosphate groups
Paired reactions where an electron donor transfers electrons to an electron acceptor are called ______ reactions. (LeO, GeR)
redox
How many bonds must be broken in ADP to form AMP?
1
Compounds that are oxidized will ______ electrons
lose electrons (LeO, GeR)
Which of the following is best associated with the electron transport system?
Oxidative phosphorylation
common coenzymes acting as electron carriers in your cells:
FAD or NAD
The three coupled pathways that many organisms utilize during the catabolism of fuel molecules are
glycolysis
Krebs cycle
Respiratory chain or electron transport
____ is the energy currency of the cells, coupling energy releasing reactions with energy requiring electrons.
ATP
For aerobic respiration, which is the final electron acceptor?
oxygen
To form ADP, a total of ______ phosphate bond(s) must be broken from ATP.
one
An electron transport system and chemiosmosis are used to produce ATP in non photosynthetic microorganisms via
oxidative phosphorylation
Which of the following is NOT a terminal electron acceptor in anaerobic respiration?
oxygen
Which of the following is an energy-poor product of aerobic respiration?
CO2 and Water H2O
Which is an energy-rich product of aerobic respiration?
ATP
Which two of the following macromolecules have the most accessible energy stored within their structures?
Carbohydrates
Lipids
In ______ respiration, electrons are transferred from fuel molecules to oxygen which acts as the terminal electron acceptor.
aerobic
Which of the following metabolic pathways begins with glucose and yields two pyruvates?
Glycolysis
The NET output of glycolysis is ____ ATP, ____ NADH, and ____ pyruvic acid molecules per glucose.
2 ATP
2 NADH
2 Pyruvic acid molecules per glucose
____ is the useful final product of aerobic respiration.
ATP
In strict aerobes and some anaerobes, pyruvic acid enters the ____, or citric acid cycle.
Krebs
Energy-rich ______ (i.e. glucose) and ______ (i.e. fatty acids) can both enter respiration pathways.
carbohydrates, sugars or glucose
lipids
The location of the Krebs cycle enzymes in eukaryotes is in the ______ matric, while in prokaryotes the enzymes are found in the ______?
mitochondrial
cytoplasm
During the Krebs cycle, ____ CO2, ____ FADH2, ____ NADH, and ____ ATP are produced per initial glucose that enters glycolysis.
4 CO2
2 FADH2
6 NADH
2 ATP
In the last step of the ETS, the electrons are passed to _____ along with hydrogen which results in the formation of ____.
oxygen
water
For each glucose that enters glycolysis, the NET output is?
2 ATP
2 NADH
2 Pyruvic acid
What is the typical “next step” for pyruvate at the end of glycolysis following normal aerobic or anaerobic respiration?
Krebs cycle
ATP ____ is an enzyme in the mitochondrial cristae that harnesses the flux of hydrogen ions across the membrane during oxidative phosphorylation.
ATP synthase
ATP is synthesized via ______ phosphorylation during the electron transport phase of respiration
oxidative phosphorylation
For each glucose that enters glycolysis, the Kreb’s cycle produces:
6 NADH
4 CO2
2 FADH2
2 ATP
The final step of the ETS in aerobic respiration occurs when electrons are passed to ________.
O2 or oxygen
______ is the generation of a proton motive force by the pumping of hydrogen ions to the outer side of the membrane during electron transport and the movement of those hydrogen ions down their electrochemical gradient through the ATP synthase enzyme.
Chemiosmosis
The active pumping of hydrogen ions across the cristae membrane sets up a concentration gradient of hydrogen ions called the _____ _____ _____
proton motive force
ATP synthase is principally composed of _____.
amino acids
In bacteria, protons are moved from the cytoplasm to the ____ space during chemiosmosis.
periplasmic space
What term is used to describe the process of ATP production from the ETS?
Oxidative phosphorylation
The electron transport chain is located in the ______ membrane of eukaryotic cells and the ______ membrane of bacteria.
inner mitochondrial; plasma
Which enzymes neutralize toxic products of respiration in aerobic organisms?
Dismutase
Peroxidase
Catalase
Production of ATP occurs by the process of ______, where hydrogen ions travel down their concentration gradient through channels in ATP synthase complexes.
chemiosmosis
What is the maximum yield of ATP from aerobic respiration in prokaryotes?
38
As hydrogen ions accumulate between the inner and outer membranes of the mitochondrion, a(n) _____ is generated which powers ATP production.
proton motive force
In prokaryotes, the protons are pumped actively across the ______ membrane by the electron transport carriers.
cellular (plasma)
True or false: Fermentation uses an organic compound for the electron acceptor.
true
When _____ supplies have been depleted in human muscle cells, ATP can be produced by _____ acid fermentation for short periods of time.
oxygen, lactic
Which is NOT a toxic product generated by side reactions during aerobic respiration?
Superoxide dismutase
Typically, ____ ATP are netted by fermentation.
2
At best, cells can generate ____ ATP from the complete oxidation of one glucose molecule during aerobic cellular respiration.
38
Fermentation results in the production of ____ ATPs than aerobic and anaerobic respiration.
fewer
Identify two different fermentation pathways
Alcoholic fermentation
Acidic fermentation
Which serves as a terminal electron acceptor in fermentation?
organic compounds
When would human cells use fermentation as opposed to respiration to produce ATP?
When oxygen is low
What term is used to describe the link between anabolic and catabolic reactions where intermediate metabolites can move between the reactions?
Amphilbolism
How many net ATP are generated during fermentation?
2
When the process of anabolism synthesizes sufficient macromolecules to support two cells and the chromosome has been duplicated, a bacterial cell will divide by a process called?
binary fission
Fermentation allows survival and growth in the absence of ______ and allows colonization of ____ environments.
oxygen
anaerobic
______ describes a metabolism where the intermediate products of a catabolic reactions can be used in anabolic reactions.
Amphibolism
Which energy-requiring process results in the formation of a new cell?
binary fission
