MICRO TEST 3
In order to utilize fatty acids for energy, fatty acids are typically linked to coenzyme A and then 2-carbon units are removed during each cycle and sent to the TCA reactions. What is the name of this pathway?
Beta-oxidation
The green wavelength is irrelevant to photosynthetic organisms that use chlorophyll-a and -b because they mainly absorb which two colors of light?
blue red
Autotrophs use the molecule____________ as their sole or principal source of carbon.
carbon dioxide
True or false: Most of the photosynthesis on Earth is carried out by plants.
FALSE
True or false: Fermentation reactions involve synthesis of ATP by oxidative phosphorylation.
False
Which two of the following are metabolic principles that save energy for the cell?
Forming biological macromolecules from simple monomers Using the same enzymes for both catabolic and anabolic pathways
Which pathway synthesizes glucose from noncarbohydrate precursors?
Gluconeogenesis
Compared to eukaryotic electron transport chains, which of these characteristics describe the ETC of E. coli?
It functions under aerobic conditions. It is shorter. ATP yield is lower. ATP yield varies with environmental conditions.
Fermenting bacteria can generate a proton motive force by reversing the normal activity of ATP synthase. Which of these statements best explain how the enzyme accomplishes this?
It hydrolyzes ATP to ADP and phosphate.
Identify all correct statements regarding the pentose phosphate pathway.
It is also called the hexose monophosphate pathway. It can occur in the absence of oxygen. It provides important precursor metabolites.
Which three statements reflect the six basic principles of anabolism?
Large molecules are made from small molecules. Anabolism consumes energy. Many enzymes do double duty.
Select all of these components that participate in cyclic photophosphorylation.
Proton motive force Photosystem I A series of electron carriers Reaction center pair P700
The reductive TCA cycle is a mechanism for ____.
carbon fixation
Bacteria that use anoxygenic photosynthesis have light-absorbing pigments called ______.
bacteriochlorophylls
Which types of microbes are particularly likely to secrete proteases, which allow them to use proteins as an energy and carbon source?
soil microorganisms fungi pathogens
Triglycerides
fatty acids often oxidized via β-oxidation pathway; common energy sources
Which metabolic pathway does not require oxygen and does not use a proton motive force to generate ATP energy?
fermentation
Because all electron bifurcation systems discovered thus far require a flavoenzyme, they are commonly called _____________- electron bifurcation (FBEB).
flavin-based
One of the basic principles guiding anabolism is that some enzymes in amphibolic pathways ____.
function in one direction only
Starch and glycogen are long chains of _____.
glucose
Any of the pathways that catabolize glucose to pyruvate can be referred to as______________
glycolysis
The pathway that synthesizes glucose from noncarbohydrate precursors is called
glyconeogenesis
As a result of electron transport, a proton gradient is formed, and ATP is synthesized by a process known as _____________phosphorylation.
oxidative
Deamination
the removal of an amino group from an amino acid
Compared to aerobic respiration, less ATP is produced during anaerobic respiration because ______.
the anaerobic electron acceptors used have less positive reduction potentials compared to oxygen
Photosystem II
P680
Compared to the P/O ratio of eukaryotic ETC, which ranges from 2.5 (for NADH) to 1.5 (for FADH2), the P/O ration of the E. coli ETC ranges from 1.3 to ______.
.67
During the catabolism of glucose by the Entner-Douderoff pathway, the organism "invests" how many ATP?
1
Chlorophyll-a absorbs light with a peak wavelength of 665 nm; the peak absorption wavelength of chlorophyll-b is ______.
645
During the complete catabolism of a molecule of glucose by aerobic cellular respiration, oxidative phosphorylation accounts for how many times more ATP than does substrate-level phosphorylation?
7
Disaccharide
A double sugar molecule made of two monosaccharides bonded together through dehydration synthesis.
n both aerobic and anaerobic respiration, ___________ is synthesized from ADP and phosphate, using a type of potential energy called the _____________ motive force.
ATP, Proton
Which of the following correctly describe electron bifurcation processes?
All systems reported to date feature a cytoplasmic enzyme that uses a flavin cofactor called a flavoenzyme. Electron flow is branched: one electron (or electron pair) moves in the endergonic direction, while the other moves in the exergonic direction.
Polysaccharides
Carbohydrates that are made up of more than two monosaccharides
The most common pathway used for degradation of glucose to pyruvate is the ______.
Embden-Meyerhof pathway
Select all correct descriptions of anoxygenic photosynthesis.
Energy from the sun is captured and converted to reducing power. Only one photosystem is used. No oxygen is produced.
Which metabolic pathways result in the catabolism of glucose to pyruvate?
Entner-Douderoff Pentose phosphate Embden-Meyerhof
Which two of the following are products of noncyclic photophosphorylation?
NADPH and A
Photosystem I
P700
Which of these are reasons why photosynthesis is one of the most significant metabolic processes on Earth?
Photosynthetic organisms are producers that serve as the base of most food chains. Almost all energy of living organisms is ultimately derived from solar energy.
Select all correct statements regarding photosystems I and II.
Photosystem II absorbs light at a shorter wavelength. Both photosystems are active in oxygenic photosynthesis. Photosystem II transfers energy to reaction center P680.
Select all correct statements about accessory pigments of photosynthesis.
Some serve to protect microbes from intense sunlight. They typically absorb light in the blue-green through yellow range. After absorption, they transfer light energy to chlorophyll.
Bacteria that use the Entner-Douderoff pathway also use which part of the Embden-Meyerhof pathway?
The second, 3-carbon phase.
Archaeorhodopsin, initially called bacteriorhodopsin, is responsible for ______.
a chlorophyll-independent photosynthesis
Because of their role in photosynthesis, carotenoids and phycobiliproteins are called pigments.
accessory
The complete catabolism of a reduced organic energy source to CO2, using glycolytic pathways and the TCA cycle, with oxygen as the terminal electron acceptor for electron transport, is called _________ respiration.
aerobic
Select the organisms that utilize lactic acid fermentation.
algae of the genus Chlorella mammals (skeletal muscle) some water molds bacteria of the genus Bacillus
Most bacteria and archaea incorporate nitrogen from _____.
ammonia nitrate
One of the basic principles guiding anabolism is that some enzymes in__________ pathways function in one direction only.
amphibolic
One of the basic principles guiding anabolism is that some enzymes in____________ pathways function in one direction only.
amphibolic
Starch and glycogen are hydrolyzed by enzymes called________ .
amylase
Precursor metabolites are central to the functioning of _____ reactions.
anabolic
Nitrification is a form of chemolithotrophy, whereas denitrification is a result of ______.
anaerobic respiration
Which metabolic pathway does not require oxygen and uses a proton motive force to generate ATP energy?
anaerobic respiration
Some bacteria carry out a type of photosynthesis in which molecules other than water are used as an electron source, called _________ photosynthesis.
anoxygenic
In order to capture many photons, about 300 molecules of chlorophyll are arranged into highly organized arrays called
antennas
Some bacteria and archaea perform chlorophyll-independent phototrophy using a light-powered proton pump called ______.
archaeorhodopsin
One of the basic principles guiding anabolism is that large molecules ____.
are made from small molecules
Organisms that use CO2 as their sole or principal carbon source are called ____.
autotrophs
Which two of these pigments are most important in photosynthetic eukaryotes?
chlorophyll b chlorophyll a
The most important light-absorbing pigments involved in oxygenic photosynthesis are the
chlorophylls
The light-absorbing pigments of some anoxygenic phototrophs are located in membranous vesicles called ______.
chlorosomes
During oxygenic photosynthesis, light energy is captured by photosystem I, and electrons move from reaction center P700, through a series of electron carriers, and back to P700 in a process called__________ photophosphorylation.
cyclic
Where does the Embden-Meyerhof pathway occurs in the bacterial cell?
cytoplasm
Select all of these conditions that will cause some chemoorganotrophic microbes to rely on fermentation.
environment lacks terminal electron acceptor some lack an electron transport chain (ETC) repression of ETC component synthesis under anoxic conditions
Most of the ATP generated during respiration is derived specifically from the ________.
etc
Many bacteria, archaea, and fungi secrete__________ to hydrolyze a variety of polysaccharides that are too large to cross their plasma membrane.
exoenzymes
Protease
hydrolyzes protein to amino acids
ransaminase can transfer the alpha-_______ group on glutamate to other carbon skeletons.
ketogluturate
The most common single type of fermentation is ______ __________fermentation.
lactic acid
Select all of these that are structural features of chlorophylls.
large, planar molecules four central nitrogen atoms long hydrophobic tail four substituted pyrrole rings
Compared to aerobic respiration, anaerobic respiration produces ______ ATP.
less
the two sources of energy available to organisms.
light and certain chemicals
One of the basic principles guiding anabolism is that small molecules are used to construct ____.
macromolecules
Due to the activity of the electron transport chain, which of these conditions are found in the mitochondrial matrix, compared to the intermembrane space?
more alkaline, more negative
Select all of these organisms that carry out oxygenic photosynthesis.
most plants, most algae, cyanobacteria
Compared to the oxidation of glucose by chemoorganotrophs, the amount of energy available from the oxidation of inorganic molecules by chemolithotrophs is ______.
much less
In general, electron transport chains operate by transferring electrons from carriers with more_______ reduction potentials, to those with more____________ reduction potentials.
negative, positive
The process of some bacteria to oxidize ammonia to nitrates is called ____________.
nitrification
The oxidation of ammonia to nitrate is known as ________; the reduction of nitrate to nitrogen gas is called_________ .
nitrification, denitrification
Those bacteria that can use nitrogenous compounds as a source of electrons are often called ______ bacteria.
nitrifying
Photosynthetic eukaryotes and cyanobacteria carry out a type of photosynthesis called___________ photosynthesis.
oxygenic
N-acetylglucosamine is a building block for the synthesis of_____ .
peptidoglycan
Carbon skeletons used as the starting substrates for the synthesis of the monomers needed to make macromolecules are ____.
precursor metabolites
Select all choices that are components of the aerobic respiration of glucose.
production of CO2. the TCA cycle a glycolytic pathway generation of pyruvate
In order to digest proteins for use as a source of energy and carbon, many microbes secrete enzymes called __________
protease
The combined chemical and electrical potential differences that are created across membranes (the inner mitochondrial membrane of eukaryotes or the plasma membrane of prokaryotes) are called the ______ _________ force.
proton motive
A key tenet of the chemiosmotic hypothesis is that electron transport chains move___________ across the inner mitochondrial membrane (or the bacterial plasma membrane).
protons
The TCA (also known as Krebs) cycle serves which of these functions?
provides one ATP or GTP for each acetyl-CoA molecule oxidized provides NADH to the electron transport chain
Lactic acid fermentation involves the reduction of ___________to lactate.
pyruvate
During oxygenic photosynthesis, light energy is captured by photosystem I, and electrons are used to _____.
reduce NADP+ to NADPH
Which of these are the most common energy sources used by chemolithotrophic microbes?
reduced nitrogen compounds reduced sulfur compounds hydrogen ferrous iron
Although sources of energy, electrons, and carbon are diverse, all are used to generate which three main products?
reducing power precursor metabolites ATP
Some autotrophic bacteria fix carbon using the ________TCA cycle.
reductive
When ammonia concentration is high, the________ amination pathway forms glutamate from α-ketoglutarate.
reductive
Another name for the Calvin-Benson cycle is the ______.
reductive pentose phosphate cycle
Long chains of glucose monomers are stored by the cell as _____.
starch or glycogen
Select any condition that applies to all microbial fermentation reactions.
the yield of ATP is relatively low compared to respiration pathways NADH is oxidized to NAD+ oxygen is not needed
Even when they are not using an electron transport chain (ETC), fermenting bacteria need a proton motive force (PMF) for ______.
transport
True or false: Some chemoorganotrophic bacteria do not respire.
true
