Bio test 2

The induced fit model of enzyme catalysis states that __________.

the active site of the enzyme changes shape after substrate binds to it

The citric acid cycle is considered a cycle because __________.

the last product is used in the first reaction to start the cycle over again

Entropy means that __________.

the quantity of usable energy declines with each energy transformation

Stroma is the __________.

thick fluid found inside the chloroplast

Water crosses the plasma membrane

through facilitated diffusion or diffusion.

ATP drives work in cells by __________.

transferring its phosphate group to other cell molecules

Which of the following depicts the correct order of the light reactions of photosynthesis?

light capture -> electron excitation -> electron transport -> making ATP -> making NADPH

An animal cell placed in a hypertonic solution will __________.

lose water by osmosis and shrivel

A drug that blocks the electron transport chain would probably cause the organism to ___________.

make insufficient ATP to survive

Diploid cells become haploid during __________.

meiosis I

The region of an enzyme called the active site has the shape and chemistry that fits one specific substrate molecule.

relationship of structure to function

If you are shipwrecked, it is not a good idea to drink seawater because .

seawater is hypertonic to the body's cells and tissues; therefore, the cells will lose water through osmosis, making you even more thirsty

In meiosis II, __________.

sister chromatids are separated into different daughter cells

Which component of the following reaction is the enzyme?sucrose + sucrase + water → sucrase + glucose + fructose

sucrase

Which component of the following reaction is the substrate?sucrose + sucrase + water → sucrase + glucose + fructose

sucrose

While serving as a visiting professor on the planet Freedonia, with infinite resources available to you, you decide to try implanting mitochondria into alien bacterial cells that can perform only glycolysis. Assuming your experiment is successful, what result would you predict?

An increase in ATP yield per glucose molecule

What is an autotroph?

An organism that utilizes light energy or inorganic compounds to meet their energy requirements

_________________ occurs when ________________.

Anaerobic respiration; oxygen is not present

How are combustion and cellular respiration similar?

At the end of both chemical reactions, carbon dioxide and water are produced.

Why are enzymes so critical to cell functioning?

Enzymes enable and regulate cellular reactions.

How do enzymes affect activation energy?

Enzymes lower the amount of energy required to activate a chemical reaction.

Because all cells have a plasma membrane, it is logical to infer that membranes first developed in the earliest forms of life on Earth.

Evolution

Which type of passive diffusion is involved in ion transport across cell membranes?

Facilitated diffusion

What is the role of fermentation in muscle metabolism?

Fermentation ensures a steady supply of NAD+ for proper glycolytic functioning during periods of low oxygen levels in muscles.

Which molecules can be broken down to generate ATP?

Glucose Fats Proteins Glycerol

Which of the following depicts the correct order of how molecules move through cellular respiration?

Glucose ->pyruvic acid -> acetic acid -> acetyl CoA

In which stage of cellular respiration is pyruvic acid produced?

Glycolosis

What is the correct order of cellular respiration?

Glycolysis -> citric acid cycle -> electron transport chain

Which of the following allows for ATP to be produced with the electron transport chain?

H+ concentration gradient

What is a difference between fermentation in human muscles and fermentation in yeast?

In human muscle cells lactic acid is produced, while yeast produces ethyl alcohol.

Where is chlorophyll found in chloroplasts?

In thylakoids

There is more oxygen gas in the air of our lungs than in the blood. Therefore, oxygen moves by passive transport from the air into the bloodstream.

Interactions within biological systems

Not all of the energy harvested during the chemical breakdown of food molecules is captured and stored in ATP. What happens to the rest of the energy?

It is released as heat.

What is a true statement about cellular respiration?

It occurs in both producers and consumers.

Which of the following is false about glycolysis?

It requires oxygen

Imagine that you synthesize a molecule that resembles the substrate of a particular enzyme but has a different chemical composition. You discover that this "substrate imposter" can bind to the enzyme's active site. What effect will the "substrate imposter" have on the reaction that is normally catalyzed by the enzyme?

It will inhibit the reaction.

Which of the following is not produced by yeast fermentation?

Lactic Acid

What part of a plant can be termed its "food factory"?

Leaves

What are the products of photosynthesis?

O2 and glucose

Which of the following best describes the process of facilitated diffusion?

Passive movement of solutes across a membrane down their concentration gradients with the involvement of membrane proteins

ATP energizes other molecules in cells by transferring phosphate groups to those molecules.

Pathways that transform energy and matter

Which of the following occurs in the first photosystem?

Photons excite electrons for transfer to an electron transport chain

Which of the following is the process that ultimately feeds the world?

Photosynthesis

Which metabolic pathways directly involve oxygen?

Photosynthesis and the electron transport chain

Which of the following features explains why plant cells do not explode as a result of osmosis?

Plant cells have a cell wall that prevents the cell from absorbing too much water.

Both animal and plant cells accumulate water through osmosis when placed in hypotonic solutions. This causes the cells to swell. Why can plant cells better tolerate this?

Plant cells, but not animal cells, have rigid cell walls that limit how far cells can expand and prevent them from bursting.

What is the end result of the Calvin cycle?

Produces sugar

Which is a true statement about the ATP cycle?

A single muscle cell needs only about one minute to recycle all of its ATP.

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

osmosis

Diffusion across a biological membrane is called

passive transport

There are three main types of cellular work: chemical, transport, and movement. Most of this work is powered by the transfer of a phosphate group from one molecule to another in a process known as

phosphorylation

You decide to try your hand at canning pickles. You immerse freshly picked cucumbers in a solution that has a solute concentration twice that found in the cucumber cells. You allow your preparation to cure for several months in a sealed jar. When you later open the jar, you find that the fluid surrounding the pickles is more dilute than when you started. This change in concentration is due to .

pickles in a hypertonic solution losing water through osmosis

When oxygen is released as a result of photosynthesis, what is its source?

Splitting of H2O

What provides the energy to drive the photosynthesis chemical reaction?

Sunlight

A plant requires which of the following for growth?

Sunlight, H2O, and CO2

What pathway in photosynthesis captures carbon dioxide?

The Calvin cycle

Which part of a reaction is changed by an enzyme?

The activation energy

What is cellular respiration?

The aerobic harvesting of chemical energy from organic fuel molecules

The enzyme lactase participates in what reaction?

The breakdown of lactose

Why are leaves green?

The chlorophyll and other pigments reflect green light while absorbing other light.

The region on an enzyme where a substrate binds is called the .

active site

The concentration of calcium in a cell is 0.3%. The concentration of calcium in the surrounding fluid is 0.1%. How could the cell obtain more calcium?

active transport

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

Photosynthetic organisms include __________.

both protists and bacteria

An enzyme is a protein that __________.

changes the rate of a metabolic reaction without being consumed by the reaction

The movement of atoms, ions, or molecules from a region of higher concentration to regions of lower concentration is called _____.

diffusion

Crossing over between homologous chromosomes normally occurs __________.

during prophase I

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

Calories are units of __________.

energy

Through energy coupling, cells use ___________, or energy-releasing, reactions to drive __________, or energy-requiring, reactions. The molecule __________ is the energy shuttle between these two types of reactions.

exergonic, endergonic, ATP

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

facilitated diffusion

The preferred source of energy for glycolysis is ___________.

glucose

Which stage of cellular respiration takes place in the cytosol?

glycolysis

In osmosis, water moves across a selectively permeable membrane toward the __________ solution; that is, toward the solution with the __________ solute concentration.

hypertonic ... greater

Which of the following is a true statement about ATP and cellular work?

ATP consists of adenosine and three phosphate groups.

Which of the following are needed for the Calvin cycle?

ATP, NADPH, and carbon

Which of the following conditions represent(s) stored (potential) energy: (1) table sugar ready to be ingested, (2) a diver about to dive off the ten-meter platform at the Olympics, or (3) a gerbil running on its exercise wheel in its cage?

1 and 2

A Calorie displayed on the nutritional label of a candy bar is equal to

1000 calories

About _________ of the energy produced by your body each day is used to sustain your brain.

20%

Which wavelength(s) of light is/are best absorbed by the chlorophyll in plants?

Blue and red

What do cell respiration and photosynthesis have in common?

Both produce (and use) ATP.

Compare the electron transfer process of photosynthesis with the electron transfer chain of cellular respiration. Which of the following are similarities?

Both use electrons to generate ATP. Both use electron carriers to donate electrons. Both involve transformation of energy. Both are found in eukaryotes.

What are the reactants for photosynthesis?

CO2 and H2O

The mass of a plant comes from __________.

Carbon

What is the difference between the use of the terms cellular respiration and respirationin biology?

Cellular respiration refers only to the breakdown of energy-rich molecules to produce ATP; respiration can refer to breathing.

Using the energy from light, what is the initial electron donor in photosynthesis?

Chlorophyll

Which stage is responsible for completing the breakdown of glucose all the way to CO2which is then released as a waste product?

Citric acid cycle

Match the following step of cellular respiration with the appropriate outputs.

Citric acid cycle - 2 CO2, ATP, 3 NADH, FADH2

Which stage of cellular respiration yields the greatest amount of ATP?

Electron transport chain

How are photosynthesis and cellular respiration connected?

The products of photosynthesis are the reactants in cellular respiration and vice versa.

Why are protons (H+) pumped across the inner mitochondrial membrane?

Their movement back across the membrane generates ATP.

What best explains the observation that enzymes are selective in the reactions they catalyze?

There is a precise compatibility between an enzyme's active site and the substrate molecule.

How do enzyme inhibitors work?

They bind to an enzyme, which alters the active site so a substrate cannot bind.

What do glycolysis and the citric acid cycle have in common?

They both directly produce 2 ATP

For what purpose(s) might a cell transport materials across its plasma membrane?

To import nutrients, to get rid of wastes, or to secrete proteins

How is breathing related to cellular respiration?

When you inhale you breathe in O2 which is delivered to your cells and is used during cellular respiration. CO2 is a waste product of cellular respiration and is exhaled.

Which of the following is an example of potential energy?

a bowling ball placed on the top shelf of a closet

In active transport,

molecules move across the plasma membrane against their concentration gradient.