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