MICRO230 Ch8
bonds; electrons
Energy management in a cell most often involves the making or breaking of chemical _____ and the transfer of _____ from one molecule to another.
2 ATP, 2 pyruvic acid, 2 NADH
For each glucose that enters glycolysis, the NET output is...
ATP, substrate, cofactor/coenzyme, water
Identify all the possible needs for an enzyme to work...
ATP, CO2, NADPH
Identify the direct components used to generate sugar in the Calvin cycle
oxidized, reduced
In a redox reaction, one compound is ____ and another compound is ______.
energy, water
Most condensation reactions require an input of _____ and result in a loss of _____
true
T/F: PS680 refers to photosystem II
false
T/F: in photosynthesis, the light-independent reactions provide the energy and reducing power needed for the light-dependent reactions
true (during photosynthesis, water is split)
T/F: light-dependent photosynthetic reactions are catabolic
true
T/F: metabolic pathways are interconnected
False
T/F: photosynthetic pigments harvest chemical energy and convert it to light energy
false (aquatic ecosystems)
T/F: plants are the principle producers of oxygen on earth
false (occurs in the light INDEPENDENT reactions)
T/F: the calvin cycle is part of the light-dependent reactions of photosynthesis
true
T/F: the souring of milk is primarily due to the activity of certain bacteria and is called homolactic fermentation
mitochondria, cell
The ETS is found embedded in the inner membrane of the _____ of eukaryotes while the ETS is found embedded in the _____ membrane of prokaryotes.
mitochondrion, cytoplasm
The Krebs cycle occurs in the __ of eukaryotic cells and the __ of bacteria.
lock and key
Which model is sometimes used to describe enzyme-substrate interactions?
Glycolysis
Which of the following metabolic pathways begins with glucose and yields 2 pyruvates?
1. Enzymes bind their substate but are not changed in the reaction 2. Enzymes lower the energy of activation for the reaction they catalyze 3. Enzymes are not consumed in the reaction they catalyze
Which of the following statements about enzymes are true?
nitrate, sulfate, carbonate, nitrate
Which oxidized compound can be used as a final electron acceptor in anaerobic respiration?
Enzymes
_____ act as catalysts in virtually all metabolic pathways
bacteria
_____ are a domain of life which contains anoxygenic organisms
carbohydrates (readily oxidized = give up electrons)
_____ are used as cellular energy sources because they are superior electron donors
Autotrophs
_____ can synthesize all macromolecules from carbon dioxide and minerals
Amphibolism
_____ describes a metabolism where the intermediate products of a catabolic reaction can be used in anabolic reactions
Amphibolism
_____ describes a metabolism where the intermediate products of a catabolic reactions can be used in anabolic reactions
competitive
_____ enzyme inhibition is a mechanism of regulation where the active site is blocked by a molecule that resembles the true substrate.
Chlorophyll
_____ is a pigment found in both PS680 and PS700
dentrification
_____ is an important process that is involved in the recycling of the nitrogen contained in organisms back into the biosphere
NAD
_____ is the most common redox (electron) carrier in cells
photolysis
_____ is the splitting of water using light energy during photosynthesis
Oxygen
_____ is the terminal electron acceptor in aerobic respiration
oxygen
_____ is the terminal electron acceptor in aerobic respiration
transamination
_____ reactions involve the transfer of an amino group an amino acid to a carbohydrate
simple, conjugated
a _____ enzyme consists of protein alone, while a _____ enzyme (or holoenzyme) consists of protein and nonprotein components
cofactor
a _____ is an organic or inorganic enzyme accessory molecule (must bind to apoenzyme in order for the enzyme to be fully functional. can be organic molecules like vitamins [coenzymes] or inorganic elements like metal ions copper and zinc)
endergonic (requires energy, anabolism) exergonic (releases energy, catabolism)
a chemical reaction that requires energy to proceed is referred to as a _____ reaction
coenzyme
a complex organic molecule, often derived from vitamins, that acts in conjunction with an enzyme is known as a....
Apoenzyme
a non-functional enzyme which needs a cofactor is called a:
photon
a quantum of light energy
Deamination
a(n) _____ reaction results in the removal of the amino group from an amino acid
Cytochromes
a(n) ______ is an iron containing (heme) protein electron carrier in the last phases of aerobic respiration
acetaldehyde
after the generation of pyruvate, pyruvate is converted into _____ which is typically reduced to form ethanol during alcohol fermentation
energy
all of life must use _____ in order to do work
constitutive enzymes
always present in relatively constant amounts regardless of the amount of substrate
catalyst
an enzyme acts as a biological _____ that alters the rate of a reaction without being changed by the reaction
ATP synthase
an enzyme in the mitochondrial cristae that harnesses the flux of hydrogen ions across the membrane during oxidative phosphorylation
Holoenzyme
apoenzyme + cofactor, conjugated enzyme
proton-motive force
as hydrogen ions accumulate between the inner and outer membranes of the mitochondrion, a _____ is generated which powers ATP production
slime layer, cell wall, capsule, nucleic acids, glycogen
carbohydrates are important in the structure of which cellular components?
accessory
carotenoids are _____ photosynthetic pigments that trap light and shuttle it to chlorophyll
ATP, NADPH
compared to oxygenic photosynthesis, anoxygenic photosynthestic pathways produce less ____ and may not produce _____
preventing the enzyme-substrate interaction, blocking the active site of the enzyme
competitive inhibition decreases the activity of an enzyme by...
labile
compounds are called _____ when they can be easily denatured, distorted, and/or degraded by mild changes to the environment
Catabolism
decomposition of complex compounds during cellular metabolism
oxygenic
during _____ photosynthesis, chlorophyll-containing organisms produce O2 as a waste product
loss of protein 3-D shape
during denaturation, which happens first to proteins?
propionic acid, ethanol, acetic acid, lactic acid
during fermentation, different organisms reduce pyruvate to a variety of chemical compounds including...
enzyme
each reaction in a metabolic pathway is catalyzed by a separate _____
protons and electrons
electron carriers shuttle both ____ and _____
protons and eletrons
electron carriers shuttle both _____ and _____
carbohydrates, lipids
energy-rich _____ (ie glucose) and _____ (ie fatty acids) can both enter respiration pathways
Induction
enzyme _____ is a type of control of enzyme synthesis where enzymes are made only when suitable substrates are present.
conjugated enzyme
enzyme with another molecule such as a metal or vitamin cofactor bonded covalently to it is called a:
site of action, type of action, substrate
enzymes are named based on.....
much larger
enzymes are typically ____ than substrates
weakly
enzymes bond ____ with their substrates
6
eventually, _____ carbon dioxide molecules will be produced from one molecule of glucose by the end of respiration
Acetyl CoA
feeds directly into the krebs cycle (Acetyl coenzyme A; the entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme.)
Bind to a cofactor
for an apoenzyme to become a functional holoenzyme, it must...
2 CO2 and 2 NADH
for each glucose that enters glycolysis, acetyl CoA formation results in the production of _____.
2
for each molecule of glucose that enters glycolysis, the last 5 reactions (of glycolysis) occur _____ times.
fructose (its isomer)
glucose-6-phosphate is converted into _____ -6-phosphate in the second reaction of glycolysis
9
glycolysis has _____ steps
anoxygenic
green and purple bacteria undergo photolithotropic or _____ photosynthesis
50 (6- carbon sugar yields 38)
how many ATPs can be synthesized from the oxidation of one 6-carbon fatty acid?
1
how many bonds must be broken in ADP to form AMP? (*think monophosphate)
2
how many net ATP are generated during fermentation?
6
how many oxygen molecules are consumed during electron transport for each glucose during aerobic respiration?
8 (citrate formation to oxaloacetate)
how many steps compose the Krebs cycle?
oxygen
Aerobic respiration requires _____, whereas fermentation and anaerobic respiration occur without this molecule
butanol, carbon dioxide, isopropanol, ethanol
Alcoholic fermentation in bacteria could result in the production of...
Metabolism
All of the chemical reactions that occur within a cell (catabolic + anabolic)
active
An enzyme's _____ site is unique for each substrate
Enzymes
Catalysts for chemical reactions in living things
alcoholic fermentation, acidic fermentation
identify 2 different fermentation pathways
water and CO2
identify what serves as energy-poor products of aerobic respiration
cell death
if internal cellular enzymes are denatured, it can lead to...
loss of proton motive force
if the membranes of the mitochondria were permeable to protons then what would happen?
substrate-level
in _____ _____ phosphorylation, phosphate groups are transferred from one molecule to AMP or ADP to form ATP
noncompetitive
in _____ enzyme inhibition, a regulatory molecule binds to a site other than the active site
competitive
in _____ inhibition, the regulator is often a product of the enzymatic reaction
Aerobic
in _____ respiration, electrons are transferred from fuel molecules to oxygen which acts as the terminal electron acceptor
Acetyl CoA
in aerobic respiration the first release of carbon dioxide occurs during the formation of ____ _____
oxygen
in anaerobic respiration, _____ is NOT used as a final electron acceptor
periplasmic
in bacteria, protons are moved from the cytoplasm to the _____ space during chemiosmosis
on the inner membrane of the mitochondria
in eukaryotes, ATP synthase enzymes are found...
mitochondrial
in eukaryotic cellular respiration, the change gradient that exists between the inner and outer _____ membranes during chemiosmosis is called proton motive force.
Glyceralhyde 3-Phosphate (G3P)
in glycolysis, _____ donates the electrons that reduce NAD to NADH
substrate (reactant)
in metabolic pathways, the products of one enzymatic reaction may act as the _____ for the next step in the pathway
acetic, lactic, succinic, formic acids, lower pH to 4.0
in mixed acid fermentation, pyruvic acid is converted into some combination of:
oxygen, water
in the last step of the ETS, the electrons are passed to _____ along with hydrogen which results in the formation of _____
aquatic ecosystems
in which ecosystem is more than 80% of the oxygen on earth produced by photosynthetic organisms?
enzyme repression
inhibits at the genetic level by controlling synthesis of key enzymes
Krebs cycle
intermediates of _____ can ultimately lead to purine and pyrimidine synthesis
Denaturation
loss of normal shape of a protein due to heat or other factor
cyclic
metabolic pathways in which the starting molecule is regenerated through the series of reactions are called _____ pathways
water
most condensation reactions involve the loss of:
aerobic
most heterotrophic organisms use _____ respiration to obtain energy
aerobic
most heterotropic organisms use _____ respiration to obtain energy
Glycolysis
multi-step, energy-yielding conversion of glucose to pyruvic acid
Adenine
nitrogen base found in DNA and RNA that component of ATP; pairs with thymine in DNA and with uracil in RNA
pece
often, regulation of metabolic pathways occurs with activation or repression of the ____ - maker enzyme.
pace
often, regulation of metabolic pathways occurs with activation or repression of the _____ - maker enzyme.
lose electrons
oxidation
Photophosphorylation
photosynthetic organisms use a sunlight-driven electron transport chain to generate ATP via _____
Denitrification
process by which bacteria convert nitrates into nitrogen gas
Specificity
protein folding determines the 3-D shape in enzymes needed for their _____ for a particular substrate (protein folding determines the 3-D shape in enzymes that is required for substrate specificity. during denaturation, the first thing proteins lose is their 3-D shape and active sites where substrates would bind)
ATP synthase
protons can only cross the mitochondrial inner membrane through _____ _____
Hydrolysis
reactions that involve the breaking of bonds and an input of water are called _____ reactions
Substrate
regulated enzyme activity is completely dependent on _____ concentration.
Endoenzymes
retained intracellularly and function there Most enzymes are endoenzymes
induced fit
slight changes occur in the shape of the enzyme in order to guide the substrate into the active site. this is referred to as an...
Anabolism
small --> large Constructive metabolism; the process of building up larger molecules from smaller ones through biosynthesis.
heterotrophs
some ____ can synthesize all cellular macromolecules from minerals and one organic carbon source
redox reaction
supply electrons to the electron transport system A chemical reaction involving the transfer of one or more electrons from one reactant to another
organic compounds
terminal electron acceptor in fermentation?
substrate level
the ATP generated in the Krebs cycle is produced by _____ phosphorylation
acetyl
the ____ group that starts the Krebs cycle can be used to synthesize lipids and proteins
carotenoids
the _____ are red, orange, and yellow pigments
regulatory site
the activity of an enzyme can be controlled through the binding of molecules to a site other than the active site is called a....
Phosphorylation
the addition of a phosphate group to a molecule
fixation
the addition of carbon dioxide to ribulose-1,5-biphosophate to begin the calvin cycle is known as carbon _____
hydrogen
the atom ___ is added to NAD to reduce it
dependent on the products from the light-dependent reactions to work
the calvin cycle is....
violet
the color of light closest to the 400 nm end of the visible light spectrum is _____
Hydrolysis
the digestion of larger substrates into smaller molecules, involving the use of water, is usually the result of ____ reactions
lactic acid
the end product of fermentation by human muscle cells is _____ _____
one
to form ADP, a total of _____ phosphate bond must be broken from ATP
lowers
typically, the presence of enzymes _____ the activation energy for a reaction to proceed
increased rate of glycolysis
what adaptation explains how some fermentative bacteria can grow as fast as they would in the presence of oxygen?
purines and pyrimidines
what can be anabolically produced with intermediates from the Krebs cycle?
oxygen
what is NOT a terminal electron acceptor in anaerobic respiration? oxygen, nitrate, carbonate, sulfate
promotes growth in oxygen rich areas of host benefits: 1 permits survival and growth in absence of oxygen 2 allows colonization of anaerobic environments 3 adapt to variations in availability of oxygen
what is NOT an advantage of fermentation to microbial survival and growth?
frees electrons, gives off O2
what is released upon photolysis (splitting water with light) during photosynthesis?
Krebs cycle
what is the "next step" for pyruvate at the end of glycolysis following normal aerobic or anaerobic respiration?
thylakoid membrane
what is the cellular location of photosynthetic pigments in eukaryotes?
phosphorylation of glucose (glucose added to phosphate)
what is the first step in glycolysis?
Vitamins
what is the most common component of coenzymes?
acetaldehyde
what is typically reduced to form ethanol during fermentation?
Apoenzyme
what term refers to a biological catalyst that lacks an essential cofactor?
anoxygenic
what type of photosynthesis does green and purple bacteria undergo?
oxygen, lactic
when ____ supplies have been depleted in human muscle cells, ATP can be produced by _____ acid fermentation for short periods of time
coenzyme
when combined with its apoenzyme, a _____ is an organic compound that functions to move (carry) functional groups from one substrate to another
binary fission
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 _____ _____
cyclic
when the starting molecule of a biochemical pathway is regenerated through the series of connected reactions, it is referred to as a(n) _____ pathway.
cell membranes
where are the photosynthetic regions in prokaryotic cells?
lipids and carbohydrates
which 2 macromolecules have the most accessible energy stored within their structures?
facilitate metabolic pathways
which best describes the function of enzymes?
beta oxidation
which catabolic pathway is used by fatty acids?
cyanide
which compound blocks cytochrome oxidase, causing a termination of aerobic respiration and death?
NADP
which compound is reduced via electrons from PS700?
catalase, peroxidase, superoxide dismutase
which enzymes neutralize toxic products of respiration in aerobic organisms?
light-dependent reactions
which generates ATP and NADPH? light dependent or light independent reactions?
ADP
which is NOT a common cellular coenzyme that carries electrons?
ADP (NAD+ is most common carrier then FAD)
which is NOT a common cellular coenzyme that carries electrons? NAD, ADP, FAD
annihilation
which is NOT a possible fate for a photon striking a photosynthetic pigment? absorbance, transmission, annihilation, reflection
oxygen
which is NOT associated with fermentation?
NOT: supplying energy for the reaction ARE: activation of the enzyme, orienting the enzyme and substrate
which is NOT function of metallic cofactors?
NADH is oxidized to NAD+
which occurs during fermentation?
1. NADH oxidized to NAD+
which occurs during fermentation? 1. NADH oxidized to NAD 2. NAD reduced to NADH 3. NADH reduced to NAD
coenzyme
which of the following acts as a carrier to move a chemical group from one substrate molecule to another? coenzyme, ATP, or metallic cofactor
high temperature, changes in pH, chemicals
which of the following can result in the denaturation of enzymes?
glucose will yield 2 pyruvates
which of the following identifies best the reason the Krebs cycle must occur twice per glucose molecule?
proteins
which of the following macromolecules can commonly act as a catalyst?
metal ions, coenzymes, small organic molecules
which of the following represent cofactors?
nitrate, sulfate, carbonate
which oxidized compounds can be used as a final electron acceptor in anaerobic respiration?
cytochrome a/a3 (cytochrome oxidase - receives electrons from cytochrome c, pick up hydrogen ions from solution, and react with oxygen to form molecule of water)
which part of the electron transport system catalyzes the terminal step of aerobic respiration?
presence of O2
which substance is a reminder that oxygenic photosynthesis is the dominant type of photosynthesis on the planet?
ribose (plus adenine and 3 phosphate groups)
which sugar is part of the structure of ATP?
Fermentation
which term describes the incomplete breakdown of glucose due to the absence of an electron acceptor for the electron transport system?
amination
which term is used to describe an addition of an amino group to a carbon skeleton?
Exoenzymes
which term is used to describe enzymes which work outside the cell?
oxidative phosphorylation
which term is used to describe the process of ATP production from the ETS? (The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.)
heterolactic fermentation
which type of acidic fermentation produces mixed acid products?
700nm
which type of light do the pigments of PS700 use for photosynthesis?
glucose is split into 2 intermediate molecules so must occur twice
why do the last 5 reactions of glycolysis occur twice for each glucose substrate?
2 pyruvates released during glycolysis
why must the Krebs cycle occur twice per glucose molecule?
ATP
(acronym) is the useful final product of aerobic respiration
ATP
(adenosine triphosphate) main energy source that cells use for most of their work coupling energy release with energy requiring reactions
Chemiosmosis
A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.
oxidation and reduction
A redox reaction involves the coupling of which 2 types of reactions?
noncompetitive
A(n) _____ inhibitor binds to a site on the enzyme that is not the active site
synthase
ATP _____ is an enzyme in the mitochondrial cristae that harnesses the flux of hydrogen ions across the membrane during oxidative phosphorylation
Calvin Cycle
ATP and NADPH are used to form high-energy intermediates in which cycle?
3
ATP has ____ phosphate groups.
photo
ATP is produced by the process of _____ - phosphorylation (prefix) in the light-dependent phase of photosynthesis
Adenosine Triphosphate (ATP)
ATP stands for...
38
At best, cells can generate _____ ATP from the complete oxidation of one glucose molecule during aerobic cellular respiration
Ubiquinone
Coenzyme Q is also known as
oxygen (NOT in fermentation!)
Consider the simplified aerobic respiration formula: sugar + O2 ---> ATP + CO2 + Heat (_____ is simply NOT part of the fermentation pathway)
ATP
Links anabolic reactions with catabolic reactions
lock and key
One type of enzyme fits one type of molecule. Change its shape and the enzyme will no longer work
wavelength (PS1 absorbs longer wavelengths above 680 nm VS PS2 absorbs shorter = 680 nm and below) (both are stationed in antennae [clusters of chlorophyll molecules in the thylakoid membranes] that absorb and send light to reaction centers)
PS700 and PS680 are named for the ____ of light to which they have the most sensitivity
photosystem 1 (PS680 = photosystem II)
PS700 refers to.....
Chemiosmosis
Production of ATP occurs by the process of _____, where hydrogen ions travel down their concentration gradient through channels in ATP synthase complexes.
Catabolism
Refers to the decomposition of complex compounds during cellular metabolism, usually with the release of energy (Metabolic pathways that break down molecules, releasing energy.)
active site
Region of an enzyme where the substrate binds (a region on an enzyme that binds to a protein or other substance during a reaction.)
inner mitochondrial, plasma
The electron transport chain is located in the __ membrane of eukaryotic cells and the __ membrane of bacteria.
Mitochondria, cytoplasm
The location of the Krebs cycle enzymes in eukaryotes is in the _____ matrix, while in prokaryotes the enzymes are found in the _____.
Substrate
The reactant on which an enzyme works.
Bioenergetics
The study of the mechanisms of cellular energy release, including catabolic and anabolic pathways, is called.... (the study of how energy flows through living organisms)
6 NADH, 2 FADH2, 4 CO2, 2 ATP
What are the products of the Krebs Cycle?
green
What color is reflected by chlorophyll?
increase substrate concentration, increase enzyme concentration, increase temperature (could be too hot), decrease temperature
What could INCREASE the rate of an enzymatic reaction which is currently not at optimal conditions?
ATP forms by substrate-level phosphorylation
What occurs in the last 3 steps of glycolysis?
green plants
Which are the primary photosynthesizers in terrestrial ecosystems?
citric acid
the first step of the Krebs cycle results in the formation of _____
phosphate
the high energy of ATP is located in the bonds of the _____ groups.
protons
the impermeability of the inner cristae membrane to ___ is crucial for the maintenance of the chemioosmotic gradient
fermentation
the incomplete breakdown of glucose in the absence of oxygen that yields only a small amount of ATP and produces a variety of byproducts is a process called...
sunlight sunlight --> CO2 & H2O = glucose (sugar for energy) photosynthesis anabolic process means product (sugar) contains more stored energy than substrates (CO2 & H2O) also, photosynthesis costs more ATP to make the sugar than ATP is produced from the catabolism of sugar in cellular respiration
the light-dependent reactions of photosynthesis are dependent on:
using or not using oxygen
the major difference between aerobic and anaerobic respiration is...
activation (activation energy: addition of an enzyme lowers reaction's activation energy which allows reaction to proceed at faster pace w/ reduced energy input)
the minimum amount of energy required for a reaction to proceed is termed the energy of _____
dependent
the phase of photosynthesis that is catabolic (energy releasing) is the light ____ reactions
dependent
the phase of photosynthesis that is catabolic (energy releasing) is the light _____ reactions
cell membranes
the photosymthetic pigments of photosynthesis are found in the _____ _____ of prokaryotes.
Glycolysis, krebs, respiratory
the primary catabolism of molecules by most organisms would include which of the 3 following pathways? respiratory chain, calvin cycle, krebs cycle, fermentation, glycolysis
heterolactic fermentation
the production of mixed acids, one being lactic acid, during fermentation is a good definition of ____ fermentation
Substrate
the specific molecule on which an enzyme acts
400 nm (violet) to 700 nm (red)
the spectrum of visible light is best described by the range between which two wavelengths?
Grana
the stacks of thylakoids embedded in the stroma of a chloroplast.
Gluconeogenesis (the formation of glucose from noncarbohydrate sources such as protein or fat...glycolysis in reverse: "making new sugar" or making glucose from pyruvate)
the synthesis of glucose from metabolic intermediates occurs through a process called _____
anoxygenic
the term _____ photosynthesis refers to photosynthesis in which bacteria use H2H4S1 or elemental sulfur rather than H2O as a source of electrons and therefore do not produce oxygen
repression (no longer being synthesized)
the term enzyme _____ refers to an inhibition of the genetic apparatus that synthesizes new copies of the enzyme which results in a decrease in the number of enzyme molecules.
primary
the term used to describe protein structure which consists of just the simple sequence of amino acids is called _____ structure
pyruvic acid
the three-carbon compound that is produced during glycolysis (needed for both the aerobic and anaerobic pathways of cellular respiration that follow glycolysis)
alcoholic and acidic
the two general categories of fermentation pathways are...
the sun
the ultimate source of most chemical energy in cells is from:
