6

Energy-Driven Inventions

 

6.1

Living Systems Require a Flow of Energy

 

 

In a phrase, how do physicists define “energy” ?

the ability to do work

 

How would a cell biologist define “energy” ?

the ability to make specific changes occur

 

The physicist’s definition of energy is not ____________ for use in defining energy changes within a living cell.

comprehensive

 

List 5 major sorts or categories of energy change within the cell.

Biosynthesis, movement, concentration, electrical potential, and heat

 

On a cold day, which of the following processes do your cells depend on to maintain an operating temperature of 37 degrees Celsius?

a.       shivering

b.       muscle contraction

c.        respiration energy production

d.       metabolic heat generation

e.        all of the above

all of the above ( A. SHIVERING ,B.)

 

Sometimes the cell pumps substances against diffusion forces that would carry those substances the other way. What term would you give to this process?

energy of concentration

6.2

Laws of Energy Flow in the Living World

 

 

____________ is freely convertible from one form to another, but ____________ can never be created or destroyed.

energy, energy

 

Systems that convert energy from one form to another are not 100% efficient, thus the amount of useful energy ____________.

decreases

 

In nature, as energy freely changes from one form to another, the total amount of energy ____________ ____________.

becomes useless

 

In living things, energy conversion is inefficient, with much energy being lost in the form of ____________.

Heat

 

What form of energy do producers use when they set about to generate chemical energy—the energy of C―H and C―O―H bonds?

solar energy

 

A producer organism is called a “producer” because it produces usable ____________ ____________.

solar energy to chemical energy

 

When your car engine burns the octane in gasoline, in what form does at least 50% of the energy of the octane end up?

engine block ( HEAT ENERGY)

 

A lit match cannot continue to burn when the wood of the matchstick is consumed. This statement illustrates what general law of energy flow?

law of conservation of matter & energy

 

In a crowded, unventilated room, what causes the temperature to rise?

people burning glucose to maintain cell life but exchange  isn’t 50% efficient ( ENERGY IS LOST IN  A ROOM AS HEATED)

6.3

Energy Flows in Chemical Reactions

 

 

Existing chemical bonds between atoms are broken and new ones are formed between different atoms. In the broadest sense this is the definition for a ____________ ____________.

chemical reaction

 

Give an example of a chemical reaction.

BACTERIA

 

Whenever chemical bonds are broken, energy is ____________. Whenever chemical bonds form, energy is ____________.

required, given off

 

Does an endergonic reaction require the input of energy, or does it give off energy?

Imput (ENERGY)

 

What term is given to the amount of energy required to break the bonds in reactant molecules?

Photosynthesis (ACTIVATION ENEREGY)

 

What is true of the bonds in reactant molecules that keeps most chemical reactions in nature from occurring?

not enough energy to break bonds 

 

When ____________ energy is not available for a given chemical reaction, the reaction will not go.

Activation

6.4

Enzymes Direct Energy Flow

 

 

How is the activation energy of desired reactions lowered in living things so that the desired reactions are able to go forward?

Enzymes ( BY PUTTING STRESS ON THE BOND)

 

What words best describe the way in which enzymes bind to reactant molecules?

active site

 

What exactly does an enzyme do to the chemical bonds within the reactant molecule?

They catalize chemical reactions. P. 130

 

By binding to reactant molecules, what effect does an enzyme have on the activation energy for a given reaction?

Catalyzes, increases

6.5

Energy Flow in Reaction Pathways: Metabolism

 

 

What name would you give to sequences of chemical reactions within cells?

metabolic pathways

 

In a(n) ____________, the product of one reaction becomes the reactant of the next reaction, and so on.

metabolic pathway

 

If the final end product of a metabolic pathway is continually removed and used elsewhere, then the reactions of the entire pathway will be pulled in the direction of making more ____________ ____________.

Polymers( END PRODUCT)

 

Suppose an excess amount of product accumulates at the end of a metabolic pathway. The product then binds to the allosteric site of the first enzyme along the pathway, shutting down the pathway. What do we call this regulatory process?

allosteric site (FEEDBACK INHIBITION)

 

An allosteric enzyme has a second binding site other than its own active site for converting substrate to product. What does this second site bind to?

specifically binds to the product of the last enzyme in the pathway(REGULATE MOLECULES)

 

If the final product of a metabolic pathway begins to build up in excess, the pathway can often be slowed down by a process called ____________ ____________.

feedback inhibition

 

A single regulatory molecule can shut down multiple metabolic pathways if it is able to add ____________ groups that alter the active site of the first enzyme in each pathway.

phosphate

6.6

Energy Pools in the Cell: ATP

 

 

Three phosphate groups are linked to a ribose sugar which, in turn, is linked to a pyrimidine base known as adenine; this phrase describes the structure of ____________.

ATP Adenosine triphosphate

 

Where in the ATP molecule is the “high energy” bond that carries potential energy and is easily broken?

last two phosphates

 

To derive energy from an ATP molecule, what bond must be broken?

high energy bond

 

Energy-releasing reactions drive biosynthetic ones forward by contributing to a pool of ____________ molecules.

ATP ENERGY STOREAGE

 

The substance ____________ would most likely enable a flagellum to drive a bacterium forward through the medium in which it is swimming.

CELLUAR ATP

6.7

Energy Flow from Carbohydrates to ATP: Respiration

 

 

In respiration, chemical energy is transferred from glucose to ATP. The energy transfer, however, is not 100% efficient. In the transfer, some of the energy is lost as ____________ (review Section 6.2, above).

Heat

 

In what major cellular process are three interrelated, exergonic pathways and oxygen used to generate large amounts of ATP from glucose molecules?

aerobic respiration

 

The term ____________ could be defined as about 30 individual, sequential chemical reactions that form three metabolic pathways: one in the cytoplasm and two within the mitochondrion.

Respiration(AEROBIC)

 

List the reactants and products of the summary reaction for aerobic respiration.

glucose, oxygen, ADP —> carbon dioxide, water, ATP

 

Write out the summary reaction for aerobic respiration.

Figure 6.15 Cytoplasm, mitochondrion, and transfer of electrons (p. 136)

 

Name the 3 stages of aerobic respiration.

glycosis, Krebs cycle, electron transfer

Glycolysis, krebs cycle, electron transfer phosphorylation

 

 

 

 

The three metabolic pathways that make up aerobic respiration are really all parts of one larger pathway because the products of early pathways (like NADH) become ____________ in the last one.

?REACTANTS

 

Aerobic Respiration: Stage 1 – Glycolysis

 

 

What is the first stage of aerobic respiration?

Glycosis

 

In the process of glycolysis, one molecule of ____________ is converted to two molecules of ____________.

glucose, pyruvate

 

Is carbon dioxide a reactant in or product of glycolysis?

Product

 

Glycolysis is valuable to a cell because it produces ____________ for driving biosynthetic processes.

ATP

 

Glycolysis is valuable to a cell because it supplies minimal energy without requiring the presences of ____________ as a reactant.

Oxygen

 

Glycolysis is valuable to a cell because it generates ____________ that can be exchanged for ATPs later.

NADH

 

Glycolysis is valuable to a cell because it produces ____________, which the Krebs cycle can further degrade for more energy.

Pyruvate

 

Aerobic Respiration: Stage 2 – The Krebs Cycle

 

 

All of the six carbon atoms in each glucose molecule leave respiration in the form of carbon dioxide. Most of them leave during which part of aerobic respiration?

Krebs cycle

 

Which of the following is not a product of the Krebs cycle?

a.       FADH2

b.       carbon dioxide

c.        ATP

d.       NAD

e.        NADH

NAD

 

The Krebs cycle’s NADH products are of value. In what way?

they contain potential energy

 

The most energetic and useful product of the Krebs cycle is ____________.

in the electrons bound to 8 carrier molecules of NADH & 2 FADH

 

Aerobic Respiration: Stage 3 – Electron Transfer Phosphorylation

 

 

What is the immediate source of electrons for electron transfer phosphorylation?

from substrates around the Krebs cycle

 

The final stage of aerobic respiration involves the phosphorylation of ____________ to ____________ by transfer of electrons.

ADP, ATP

 

During the electron transfer reactions, protons (H+ ions) are pumped (moved) to one side of the inner membrane of the mitochondrion. The value of this pumping is that the resulting proton gradient is then used to ____________.

insulate the inside from the outside & build charge

 

What is the most valuable product, energetically, of electron transfer phosphorylation?

ATP

 

The value of the three stages of aerobic respiration is their ability to break down glucose, a single molecule, with the resultant production of about ____________ ATP molecules.

Three

6.9

Energy Flow from Photons to Carbohydrates: Photosynthesis

 

 

____________ organisms build their own energy-rich molecules using solar energy.

Dead

 

Plants are considered autotrophic because their cells contain what critical molecule?

ATP

 

Name a process that uses chlorophyll molecules to produce high-energy carbohydrates.

photosynthesis

 

List the reactants and products for the overall process of photosynthesis.

carbon dioxide + H2O = glucose + oxygen

 

In photosynthesis, the H atoms used to make high-energy carbohydrates like glucose come from which reactant molecule?

carbon dioxide

 

Photosynthesis: Stage 1 – Light-Dependent Reactions

 

 

The wavelengths of light used in photosynthesis are found in the ____________ portion of the electromagnetic spectrum.

Light

 

Each wavelength of light has its own ____________ level.

Energy

 

When light of the correct wavelength hits a photosynthetic pigment molecule, an electron within one of its atoms becomes ____________.

Quinone

 

What is the value of accessory pigments within the chloroplast’s structure?

they transfer the energy of absorption to nearby chlorophyll molecules

 

Accessory pigments and chlorophylls work together within the thylakoid membrane in clusters called ____________.

photosystems

 

Photosystems harvest light energy and use it to transfer electrons to ____________ molecules.

Quinones

 

The light-dependent reaction is like the last stage of aerobic respiration in that both reaction sequences carry out ____________ ____________ phosphorylations.

electron transfer

 

The light-dependent reaction is like the last stage of aerobic respiration in that both processes generate the energy-rich ____________ molecule.

ATP

 

The light-dependent reaction is like the last stage of aerobic respiration in that both processes involve the flow of ____________.

Oxygen

 

The light-dependent reaction is like the last stage of aerobic respiration in that both systems are lodged with a ____________ surface.

 

 

What is the role of NADPH in the process of photosynthesis? What does it carry? From where to where?

NADPH carries high-energy electrons to the second stage of photosynthesis where they are used to create energy-rich bonds.

 

NADPH is formed when it accepts high-energy ____________ from an excited photosystem.

Electrons

 

List 3 products of the light-dependent reaction.

water, chloroplasts, oxygen

 

Photosynthesis: Stage 2 – Light-Independent Reactions

 

 

In the chloroplast, light-dependent reactions take place in the ____________ membrane, while light-independent reactions take place in the fluid of the ____________.

thykaloid, stroma

 

Where, within the chloroplast, are new molecules of glucose generated?

Cytoplasm

 

The immediate product of photosynthesis, three-carbon PGALs can be assembled together to generate ____________ molecules.

Starch RIBULOSE 1,5 BISPHOSPHATE

 

The immediate product of photosynthesis, three-carbon PGALs can also find their way into ____________ sugar molecules.

Second

 

The immediate product of photosynthesis, three-carbon PGALs may eventually become part of the subunits of ____________ polymers.

STARCH

 

The immediate product of photosynthesis, three-carbon PGALs are used to generate transport and ____________ forms of carbohydrates.

GENERATE

6.10

Energy Flow: An Integrated Picture

 

 

The overall process that uptakes energy-poor molecules (CO2 and H2O) from their reservoirs in nature and converts them into energy-rich molecules is ____________.

Photosynthesis ( CARBON CYCLE)

 

What 2 processes complement each other within the global carbon cycle?

photosynthesis & respiration

 

____________ organisms specialize in capturing energy.

autotrophic bacteria & plants

 

____________ organisms are highly efficient at handling energy.

autotrophic bacteria & plants (PLANTS)

 

____________ organisms generate far more C―H bond energy than they themselves utilize.

autotrophic bacteria & plants (SERVANT)

 

 

 

7

Information and Its Expression in the Cell

 

7.1

The Need for Biological Information

 

 

Biological information must exist because cell structure is ____________ enough to require information for its construction.

REQUIRE INFORMATION

EXPRESSED IN CELLUAR STRUCTURE

7.2

The Nature of Biological Information

 

 

Who discovered DNA and from what source did he isolate it?

Friederick Miescher, the nuclei of pus cells (nuclein) 1844-1895 ( A CRUDE FRACTION FROM THE NUCLEI OF PUS CELLS ) 

 

What was the principle tool Rosalind Franklin used to unravel the structure of DNA?

x-ray ( CRYSTALLOGRAPHY)

 

DNA contains two chains of nucleotides in which ____________ and ____________ alternate in supporting each chain structurally.

Sugars, phosphates

 

Where in the DNA molecule’s structure is the genetic information located?

sequence of bases

 

Where in the cell is DNA stored?

nucleus, mitochondria

 

DNA is stored within a partially-condensed fiber called ____________.

Bacteria

 

Griffith exposed weak living bacteria to just the fluids from heat-killed virulent bacteria. Some of these weak bacteria became virulent and could now kill mice. What control experiment did he do to argue that his weak bacteria changed to virulence in these studies? Select a choice from below.

a.       He grew his non-virulent bacteria for several years before infecting mice with them.

b.       He injected viruses into his mice to test their resistance to viral infection.

c.        He injected virulent bacteria into rabbits to see if they would die.

d.       He injected heat-killed virulent bacterial fluids into a mouse to make sure the mouse would survive.

e.        He isolated two strains of bacteria and maintained them in colonies.

B