bio test 2

Which of these is NOT a product of glycolysis?

FADH2

Which of the following molecules is broken down in cellular respiration, providing fuel for the cell?

Glucose

The light reactions of photosynthesis generate high-energy electrons, which end up in __________. The light reactions also produce __________ and __________.

NADPH : ATP : oxygen

The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of______

active transport.

Which of the following is an INCORRECT pairing between a photopigment and its characteristic or function?

chlorophyll a: absorbs mainly green wavelengths

A(n) _____ , which is often a vitamin, binds to an enzyme and plays a role in catalysis.

coenzyme

Azidothymidine (AZT) is an antiretroviral drug used in the treatment of HIV. It shares a structural similarity to a nucleotide. What might be the mode of action for this drug?

competitive inhibition

You are interested in measuring the effects of increased levels of CO2 on plant growth. Which of the following would allow you the most control over the independent variables?

growth chambers

Which of these are by-products of cellular respiration?

heat and water

Which element of a photosystem becomes reduced and then directly passes electrons to NADP+ to form NADPH?

primary electron acceptor of Photosystem I

What is the function of the sodium-potassium pump in nerve cells?

pump Na+ out of the cell and K+ into the cell

Which method of transport uses coated pits?

receptor-mediated endocytosis

In eukaryotes, most of the high-energy electrons released from glucose by cellular respiration __________.

reduce NAD+ to NADH, which then delivers them to the electron transport chain

In photosynthesis, CO2 is _______ while H2O is _________.

reduced to C6H12O6: oxidized to O2

Both mitochondria and chloroplasts _____.

use an H+ gradient to produce ATP

Aquaporins are proteins that facilitate the transport of __________ across the membrane.

water

What transports electrons from the light reactions to the Calvin cycle?

NADPH

For each glucose that enters glycolysis, _____ NADH enter the electron transport chain.

10

How many NADH are produced by glycolysis?

2

The splitting of one molecule of H2O in the light reactions yields which of the following?

2 electrons, 2 H+, ½ O2

In 2015, almost _____countries forged an agreement to limit global warming to less than ____ by the year 2100.

200: 2ºC

How many molecules of ATP are produced in 1) glycolysis; 2) the citric acid cycle; and 3) oxidative phosphorylation?

2: 2: 28

Each turn of the citric acid cycle yields which of the following molecules that will go on to donate their electrons to the electron transport chain?

3 molecules of NADH and 1 molecule of FADH2

Visible light occupies wavelengths of about ______ to _______ on the electromagnetic spectrum. In general, longer wavelengths of light have photons with ______ energy than shorter wavelengths.

380 to 750 nm: lower

Numbers matter in science! Plants use about _____ % of the carbohydrates they make as fuel for cellular respiration. The burning of fossil fuel has led to an increase of more than ____% in the concentration of CO2 in the atmosphere since the start of the Industrial Revolution. Deforestation accounts for about ____% of greenhouse gas emissions.

50%: 45%: 10%

There are about ______ chloroplasts in 1mm2 of leaf surface. Chloroplasts "live" in _______ cells. The thick fluid inside chloroplasts is called the _____. What occurs in this fluid?

500,000: mesophyll: stroma: the Calvin cycle

Which of the following equations represents photosynthesis?

6CO2 + 6H2O → C6H12O6 + 6O2

An hour of walking at 3 mph consumes approximately _____ times as much energy as an hour of sitting and writing.

8

In glycolysis, what starts the process of glucose breakdown?

ATP

Which energy-rich molecule produced by cellular respiration directly powers cell work?

ATP

What two molecules are produced by the light reactions and used to power the Calvin cycle?

ATP and NADPH

The product of Photosystem II is ______. The product of Photosystem I is _____.

ATP: NADPH

Which of the following is a difference between active transport and facilitated diffusion?

Active transport requires the expenditure of cellular energy, and facilitated diffusion does not

Which of the following is the first event after a photysynthetic pigment absorbs a photon of light?

An electron in the pigment molecule jumps to a higher energy level.

What connects the two photosystems in the light reactions?

An electron transport chain

What is meant by the term "enzyme specificity"?

An enzyme catalyzes only one type of reaction.

What is the major diference between autotrophs and heterotrophs?

Autotrophs make their own food: heterotrophs consume or decompose other organisms.

Which of the following do C4 plants and CAM plants have in common?

Both fix CO2 into an initial 4-carbon compound.

Which of the following is an INCORRECT statement comparing lactic acid fermentation and alcohol fermentation?

Both reduce pyruvate to lactate.

Which of the following statements about brown fat is INCORRECT?

Brown fat produces more heat and more ATP than white fat.

Which of the following is the summary equation for cellular respiration?

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP + heat

The bubbles in dough that arise after yeast has been added are ______.

CO2, a product of alcohol fermentation

What provides the carbon atoms that are incorporated into sugar molecules in the Calvin cycle?

Carbon dioxide (CO2)

________ energy is the type of ________ energy used to power the work of the cell.

Chemical: potential

In which of the following organelles does photosynthesis take place?

Chloroplast

Which of the following is a CORRECT statement about aquaporins?

Each aquaporin molecule allows billions of molecules of water to cross the plasma membrane each second.

Which of the following best describes the electron transport chain?

Electrons pass from one carrier to another, releasing a little energy at each step.

The pesticide malathion and some drugs used as anesthetics both block an enzyme that is critical for transmitting nerve impulses. Why don't patients die like insects when they undergo surgery?

Enzyme inhibition with malathion is irreversible but with anesthetics, reversible.

Imagine a U-shaped tube with a membrane at the bottom of the "U". The membrane is permeable to glucose, sucrose and water. You place a concentrated glucose solution on Side A and an equally concentrated sucrose solution on Side B. Describe the movement of each solute across the membrane during the first few hours.

Glucose will move into Side B down its concentration gradient, and sucrose will move into Side A down its concentration gradient

_______ generates the ATP created in fermentation reactions.

Glycolysis

What provides electrons for the light reactions?

H2O

What is the main cause of the current amplification of global climate change?

Human activity is increasing the concentration of greenhouse gases, which delays the escape of heat from the planet.

What is one way of reducing the effectiveness of a competitive enzyme inhibitor?

Increase the concentration of the substrate.

One model of the cell membrane is that it is a "fluid mosaic." What does this mean?

It consists of proteins suspended in a fluid phospholipid bilayer.

What is the "fate" of oxygen after it is created in photosynthesis?

It diffuses out of the thylakoid and eventually exits the leaf through stomata.

What is the role of oxygen in the electron transport chain?

Its high electronegativity makes it the final electron acceptor.

Which of the following leaf types would be the most efficient at absorbing sunlight?

Large, broad leaves

What is the meaning of the phrase "greenhouse gases" in reference to climate change?

Methane, water vapor, and carbon dioxide trap heat, as do greenhouses

Given the relatively modest number of calories burned by anything but the most vigorous activities, why can people consume over 2,000 kilocalories a day, yet maintain a healthy body weight?

Most of the energy consumed in food is spent maintaining the body's functions, so only a fraction of food energy needs to be burned in exercise.

During electron transport, energy from _____ is used to pump hydrogen ions into the _____.

NADH and FADH2 ... intermembrane space

Which of the following statements about NADH and NAD+ is correct?

NADH delivers electrons to the electron transport chain in oxidative phosphorylation and becomes oxidized to NAD+.

Oxygen is the final electron acceptor for cellular respiration. What is the final electron acceptor in the light reactions of photosynthesis?

NADP+

Photorespiration consumes ____ and releases ____. It uses the enzyme _____.

O2: CO2: rubisco

Current evidence indicates that the process of photosynthesis arose more than three billion years ago. Its origin had a huge impact on existing organisms and on the physical characteristics of the biosphere. Which major physical change could be attributed to photosynthesis?

Photosynthesis drastically increased the oxygen content of the atmosphere.

Which of the following is a correct statement about photosynthetic pigments?

Photosynthetic pigments are located within the thylakoid membrane bilayer

In what way, if any, does osmosis differ from simple diffusion?

Polar water molecules cluster with hydrophilic molecules, so only free water diffuses down its concentration gradient

Which of these statements is TRUE with regard to this animation?

Sodium and potassium ions are transported against their concentration gradients.

At what point in photosynthesis is sugar made? Where does this occur?

Step 2 of the Calvin cycle: in the stroma of the chloroplasts

Which of the following structures allows for gas exchange between the tissues of a leaf and the atmosphere?

Stomata

When you hear "Substance X is moved against its concentration gradient," what do you think of?

Substance X has moved from a region of lower to a region of higher concentration with the help of ATP.

What benefits do scientists think might result from increasing the amount of brown fat in people who are obese or who have type 2 diabetes?

Such people might benefit from a higher proportion of brown to white fat, which would reduce the amount of stored fat.

Although the reactions of the Calvin cycle are not directly dependent on light, they usually do not occur at night. Why?

The Calvin cycle depends on products of the light reactions.

What is the consequence of this inhibition as Product X accumulates?

The concentration of Molecule B increases.

What was the main difference between the experimental and control study plots in the Free-Air CO2 Enrichment (FACE) experiment concerning the effects of atmospheric gases on plant growth?

The experimental plots were exposed to levels of CO2 that were about 150% of present-day levels

Which of the following is a correct statement about the relationship between photosynthesis and cellular respiration?

The products of photosynthesis are the reactants of cellular respiration, and the products of cellular respiration are the reactants of photosynthesis.

A red chemical dye known as phenol red changes to yellow when CO2 is present. A small green plant seedling is placed in phenol red and then placed in the dark. Which of the following is most likely to occur?

The solution is red to begin with, and it will turn yellow because respiration is occurring.

Lactase is essential for digesting lactose in milk. This enzyme is specific for this sugar. Why?

There is a precise compatibility between the active site and the lactose molecule.

Researchers used frog eggs to learn more about aquaporins. What characteristic of normal frog eggs was essential in these studies?

They are largely impermeable to water.

Which of the following statements about coenzymes is correct?

They are organic cofactors with enzymes in reactions.

Why do fats make such excellent cellular fuel?

They contain many hydrogen atoms.

In what sense are living cells more efficient than internal combustion engines?

They convert a greater proportion of fuel to useful energy

True or false. Guard cells open during the day to allow gases to flow through the stomata.

True

Through respiration, humans breathe in O2 and breathe out CO2. However, what would happen if we did not breathe in O2?

We would not make enough ATP to meet our energy requirements

Which of the following processes must be present before ATP can be generated in oxidative phosphorylation?

a higher concentration of H+ within the mitochondrial intermembrane space than within the mitochondrial matrix

In this diagram of the plasma membranes of two adjoining cells, identify the protein indicated by the white arrow, including its function.

a receptor protein that binds with a signaling molecule and relays the message into the cell by activating other molecules inside the cell

Which of these is exhibiting kinetic energy?

a space station orbiting Earth

Walking at 3 mph burns about 245 kcal/hour. A slice of pizza contains about 474 kcal. How far would you have to walk to burn off the calories in that slice of pizza?

about 6 miles

Which of these enters the citric acid cycle (also called the Krebs cycle)?

acetyl CoA

Which of these is NOT a product of the citric acid cycle (also called the Krebs cycle)?

acetyl CoA

An enzyme speeds up reactions by lowering the _____

activation energy

An enzyme is specific because the shape of its _____ matches only particular reactants

active site

When in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. This molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. Using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane?

active transport

Utah's Great Salt Lake has an average salinity seven times higher than that of the oceans. Very few multicellular organisms live in this harsh environment. An example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. These brine shrimp must _____.

actively pump water back into their cells to counter its loss due to osmosis

What type of organism was used in Calvin's experiments?

algae

Which of the following links Photosystem II and Photosystem I in the light reactions of photosynthesis?

an electron transport chain

A plant cell placed into an isotonic solution _______. An animal cell placed into an isotonic solution _______.

becomes flaccid: neither swells nor shrivels

Energy defined as

capacity to cause change (do work)

In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive carbon. The mice were closely monitored, and in a few minutes, radioactive carbon atoms showed up in __________.

carbon dioxide

The Calvin cycle describes the conversion of ___.

carbon dioxide to carbohydrates

The radioactive isotope used in the Calvin experiments was ____.

carbon-14

An enzyme is considered a(n) _____ because it speeds up a chemical reaction without being used up.

catalyst

In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?

cellular respiration

Before refrigeration, meat was preserved by adding ________. What effect did this have on any contaminating bacteria or fungi?

concentrated salt solutions: plasmolysis

A single glucose molecule produces about 38 molecules of ATP through the process of cellular respiration. However, this only represents approximately 34% of the chemical energy present in this molecule. The rest of the energy from glucose is __________.

converted to heat

In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells.

cytoplasm

High temperatures or changes in pH can _____ an enzyme, causing it to lose its shape and biological activity.

denature

At which stage of cellular respiration is the first molecule of CO2 released?

during the oxidation of pyruvate to acetyl CoA

Building a molecule of ATP is an ________process. Hydrolyzing a molecule of ATP is an _______ process. This cycle is an example of _________.

endergonic: exergonic: energy coupling

Photosynthesis is an _______ process. Energy from ______ allows the production of products with ________.

endergonic: the sun: higher potential energy than the reactants

The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of

endocytosis.

"Conservation of energy" refers to the fact that _____.

energy cannot be created or destroyed but can be converted from one form to another

Oxidative phosphorylation ocurs in the ______ and produces _____.

inner mitochondrial membrane: ATP

A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of______

facilitated diffusion.

Energy cannot be created or destroyed

first law of thermodynamics

At what stage of active transport is ATP needed?

for the transport protein to change its shape

Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________.

four; 3 NADH and 1 FADH2

Which out of the listed choices is the earliest metabolic pathway to have developed in living things?

glycolysis

What is the correct order of the stages of cellular respiration?

glycolysis, citric acid cycle, oxidative phosphorylation with chemiosmosis

Chemical energy is a form of _____ energy.

potential

A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to treat people with bacterial infections. However, he can't do this because _____.

human cells also perform glycolysis; the drug might also poison them

A plant cell placed in a(n) _______ solution will lose water and plasmolyze.

hypertonic

There is a net diffusion of water out of an animal cell when it is placed in a(n) _____ solution.

hypertonic

This cell is in a(n) _____ solution.

hypertonic

You know that this cell is in a(n) _____ solution because it _____.

hypertonic solution ... lost water

An animal cell placed in a(n) _____ solution will gain water, swell, and possibly burst.

hypotonic

The ideal osmotic environment for a plant cell is a(n) _______environment.

hypotonic

You know that this cell is in a(n) _____ solution because the cell _____.

hypotonic ... swelled

We inhale O2 and we exhale CO2. Carbon dioxide is produced __________.

in the reaction that creates acetyl CoA (coenzyme A) from pyruvate

The _____ between an active site and its substrate often strains bonds and helps the reaction proceed.

induced fit

A plant cell surrounded by a(n) ______ solution will be flaccid (limp).

isotonic

The ideal osmotic environment for an animal cell is a(n) _____ environment.

isotonic

The proximate (immediate) source of energy for oxidative phosphorylation is _____.

kinetic energy that is released as hydrogen ions diffuse down their concentration gradient

In muscle cells, fermentation produces _____.

lactate and NAD+

Sports physiologists at an Olympic training center want to monitor athletes to determine at what point their muscles begin to function anaerobically. They could do this by checking for a buildup of _____.

lactic acid

Which is the correct sequence of events in the transfer of energy in a photosystem after a plant has been exposed to light?

light-harvesting complex to chlorophyll a molecules to primary electron acceptor

As an energy source, photoautotrophs use ______; chemoautotrophs use _______; and heterotrophs use ________.

light; inorganic chemicals; photoautotrophs

Enzymes ______ the activation energy of a reaction. The energy change between products and reactants is _______ for a reaction that is catalyzed versus one that is not.

lower: the same

A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell would she use as a source of these enzymes?

mitochondrial matrix

In active transport,_____

molecules move across the plasma membrane against their concentration gradient.

When molecules move down their concentration gradient, they move from where they are ______ to where they are _____

more concentrated; less concentrated.

Which of the following prevents the cells of a freshwater fish from becoming hypotonic and bursting?

osmoregulation

What name is given to the process by which water crosses a selectively permeable membrane?

osmosis

The two-carbon compound that enters the citric acid cycle joins with which of the following molecules before it begins its turn around the cycle?

oxaloacetate, a 4-carbon molecule

In cellular respiration, most ATP molecules are produced by _____.

oxidative phosphorylation

Some human cells, such as nerve cells, are restricted to aerobic respiration to recycle NADH and FADH2. If these cells are deprived of oxygen, then __________.

oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain

The final electron acceptor of cellular respiration is _____.

oxygen

Both a living cell and an automobile convert fuel and ______ to the waste products ___________. In the process, ______ is produced, which represents the entropy of the reaction.

oxygen: CO2 and water: heat

Diffusion across a biological membrane is called

passive transport

In C3 plants the conservation of water promotes _____.

photorespiration

Bacteria have no membrane-enclosed organelles. However, some still generate ATP through cellular respiration. Where might the electron transport chain be found in these organisms?

plasma membrane

Endergonic reactions _______ energy and result in products that have _____ potential energy than the reactants.

require: higher

Energy can be transferred or transformed, always increases disorder of randomness, is the

second law of thermodynamics

Paper chromatography is used to _____.

separate components in a material of interest

In a catalyzed reaction, a reactant is often called a(n) _____

substrate

In glycolysis, ATP molecules are produced by _____.

substrate-level phosphorylation

In the citric acid cycle (also called the Krebs cycle), ATP molecules are produced by _____.

substrate-level phosphorylation

Which is the most inclusive and correct list of substances that use facilitated diffusion to cross cell membranes?

sugars, amino acids, ions, water

What is the driving force for the production of ATP in the light reactions?

the H+ concentration gradient across the thylakoid membrane

In the Calvin cycle, the source of CO2 is ______. The source of energy is _____ and the source of electrons for the reduction reactions is ______.

the air: ATP: NADPH

In addition to providing fuel in the form of ATP, the intermediates of cellular respiration also provide ______.

the building blocks of proteins, fats, and carbohydrates

Most NADH molecules generated during cellular respiration are produced during __________.

the citric acid cycle

Several genetic disorders of mitochondria have now been identified. If such a defect resulted in a less active electron transport chain, what would you predict might occur? (Note: think of this in terms of basic mechanisms: genetic disorders rarely affect just one process.)

the concentration of ADP within the mitochondrial matrix would increase

Which of the following events takes place in the cell's cytosol?

the formation of ATP by substrate phosphorylation

Which of the following is the best description of substrate-level phosphorylation in glycolysis?

the transfer of a phosphate group from a substrate molecule to ADP

Water crosses the plasma membrane_____

through facilitated diffusion or diffusion.

The light reactions take place in the _________ and the Calvin cycle takes place in the _________.

thylakoids; stroma

C4 plants differ from C3 and CAM plants in that C4 plants _____.

transfer fixed carbon dioxide to cells in which the Calvin cycle occurs

In glycolysis there is a net gain of _____ ATP.

two

Glycolysis is a series of reactions that can be divided into two phases: an "energy investment" and an "energy payoff" phase. Which of the following is produced at the end of the "energy investment" phase in the metabolism of one molecule of glucose?

two molecules of glyceraldehyde-3-phosphate (G3P), a 3-carbon sugar

Two competing theories about the source of oxygen in photosynthesis were tested in the 1940s-50s using radioactive isotopes. About what did the theories disagree?

whether O2 released in photosynthesis originated in H2O or in CO2