Metabolism/Photosynthesis

Summary of the calvin cycle: -6 CO2 enter and are..... - 12 NADPH from the light reactions...... - 18 ATP from the light reactions..... - NADP+ and ADP are regenerated to....

- Converted into glucose - Are used to reduce Carbon atoms - Provide energy for - Return to the light reactions

Visible light spectrum

- Includes colors of light we can see - Includes wavelengths that drive photosynthesis

Phase 3: Regeneration of CO2 acceptor

- The remaining G3P used to regenerate RuBP to use CO2 and other

First law of Thermodynamics

- Total amount of energy in the universe remains constant -Energy is not created nor destroyed, but can change forms

Steps in light reactions

- When a pigment absorbs light, it goes from a ground state to an excited state, which is unstable - The electron is excited to the primary acceptor - Water then splits replacing the electrons that just left the photosystem - H+ are stored in the thylakoid space -1/2 O2 is released from leaf

Structure of ATP

-5-carbon sugar - Nucleotide base - Triphosphate tail

Induced fit

-An enzymes active site can conform to fit substances that are similar to, but not exactly the same shape as the active site - The polar/non-polar regions and charged regions of the substrate alter the folding of the enzyme

Phase 1: Carbon fixation

-CO2 enters and joins RuBP (5-carbon sugar) to become a 6-carbon sugar - 3-phosphoglycerate a 3-carbon sugar is formed when 6 carbon sugar splits

Second law of Thermodynamics

-Energy is lost as heat as it changes forms -Entropy disorder is increasing over time

ATP and ADP

-Enzymes can break bond between outermost pond tail - This releases energy which can be transferred to an endergonic reaction

Photolysis

-In the thylakoid membranes of a chloroplast during light-dependant reactions, two molecules of water are split to form oxygen, hydrogen ions, and electrons. -a process of photosynthesis in which water is split into H+ and OH-; the hydrogen ion is then joined to NADP

Phase 2: Reduction

-NADPH transfers electrons to PGA reducing it and forming G3P - Some G3P will go on to form glucose and other materials for the plant

Photosynthesis

-Process that converts solar energy into chemical energy -occurs in plants, algae, certain other protists, and some prokaryotes -these organisms are called photoautotrophs - they use the energy of sunlight to make organic molecules from water and carbon dioxide

What are two possible explanations for the existence of photorespiration, a process that can result in the loss of as much as 50% of the carbon fixed in the Calvin Cycle?

-Said to be an evolutionary relic. The early atmosphere in which primitive plants originated contained very little oxygen, so it's hypothesized that the early evolution of RuBisco was not influenced by its lack of discrimination between O2 and CO2. - It may function as a safety valve, preventing excess NADPH and ATP from reacting with oxygen and producing free radicals, as these can damage the metabolic functions of the cell by subsequent reactions with lipids or metabolites of alternate pathways.

Why does ATP give up energy so easily?

-The three phosphate groups clustered together puts negative charges in close proximity - The negative charges repel each other destabilizing the molecule - Removing the phosphate group makes the more stable ADP

The active site can lower and E sub A barrier by.....

-orienting substrates correctly - straining substrate bonds - providing a favorable microenvironment - covalently bonding to the substrate

Activity of an enzyme is affected by.....

-temperature and pH -

1st or 2nd law of thermodynamics: A hydroelectric plant at a waterfall, producing electricity

1

1st or 2nd law of thermodynamics: Apple trees absorbing energy from the sun and storing the energy in the chemical bonds of starch and sugar

1

1st or 2nd law of thermodynamics: Egyptian pyramids crumbling slowly to dust over long periods of time

1

1st or 2nd law of thermodynamics: The glow of a firefly

1

1st or 2nd law of thermodynamics: The glow of an incandescent bulb following the flow of electrons through a wire

1

1st or 2nd law of thermodynamics: The movement of a gasoline-powered automobile

1

1st or 2nd law of thermodynamics: Earth's sun is continuously losing energy to its surroundings

2

1st or 2nd law of thermodynamics: Humans running the 100-meter dash following usual food intake

2

1st or 2nd law of thermodynamics: The death and decay of an organism

2

Transformed energy results in increasing disorder is....

2nd law of thermodynamics

Overall equation of photosynthesis......

6CO2+6H2O+ Light energy-------C8H12O6 + 6O2

Entropy

A measure of disorder, or randomness

Anabolism

A metabolic pathway that consumes energy to synthesize a complex molecule from simpler molecules

Metabolic pathways

A series of chemical reactions that either builds a complex molecule (anabolic) or breaks down a complex molecule to simpler molecules (catabolic) -catalyzed by enzymes

In the metabolic pathway A-B-C-D-E, what effect would molecule E likely have on the enzyme that catalyzes A-B? a. Allosteric inhibitor b. Allosteric activator c. Competitive inhibitor d. Feedback activator e. Coenzyme

A. Allosteric inhibitor

One way in which a cell maintains metabolic disequilibrium is to a. Siphon products of a reaction off to the next step in a metabolic pathway b. Provide a constant supply of enzymes for critical reactions c. Use feedback inhibition to turn off pathways d. Use allosteric enzymes that can bind to activators or inhibitors e. Use the energy from anabolic pathways to drive catabolic pathways

A. Siphon products of a reaction off to the next step in a metabolic pathway

What happens to ADP?

ADP can be sued to reform ATP when more energy is available

Accessory pigments

Absorb energy in the yellow portion of the spectrum to utilize some of the lost energy

Catalytic cycle of an enzyme: Step 3

Active site (and R groups of its amino acids) can lower E sub A and speed up a reaction

Catalytic cycle of an enzyme: Step 6

Active site available for 2 new substrate molecules

ATP, adenosine triphosphate

Adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells.

Explain why this reaction releases so much energy

All three phosphate groups are negatively charged. These like charges are crowded together and their mutual repulsion contributes to instability of this region of ATP. Triphosphate tail of ATP is chemical equal of compressed spring

Cooperativity is a form of....

Allosteric regulation that can amplify activity

Stoma

Allow exchange of carbon dioxide and oxygen between the surrounding air and photosynthetic cells inside the leaf. Also avenues for evaporative loss of water

Carotenoids

An accessory pigment, either yellow or orange, in the chloroplasts of plants and some prokaryotes. By absorbing wavelengths of light that chlorophyll count, carotenoids.............................. - Absorb violet and blue wavelengths but transmit red, orange, and yellow

System with low free energy: Equilibrium

At equilibrium

Which of the following terms best describes this reaction? a. Nonspontaneous b. -AG c. Endergonic d. Coupled reaction e. Anabolic reaction

B. -AG

When glucose and O2 are converted to carbon dioxide and water changes in total energy, entropy, and free energy are correctly represented as a. -AH, -AS, -AG b. -AH, +AS, -AG c. -AH, +AS, +AG d. +AH, -AS, +AG e. -AH, -AS, +AG

B. -AH, +AS, -AG

Zinc, an essential trace element, may be found bound to the active site of some enzymes. Such zinc ions most likely function as a. A coenzyme derived from a vitamin b. A cofactor necessary for catalysis c. A substrate of the enzyme d. A competitive inhibitor of the enzyme e. An allosteric activator of the enzyme

B. A cofactor necessary for catalysis

At equilibrium, a. No enzymes are functioning b. Free energy is decreasing c. The forward and backward reactions have stopped d. The products and reactants have equal values of H e. AG is 0

B. Free energy is decreasing

When a cell breaks down glucose, only about 34% of the energy is captured in ATP molecules. The remaining 66% of the energy is a. Used to increase the order necessary for life to exist b. Lost as heat, in accordance with the second law of thermodynamics c. Used to increase the entropy of the system by converting kinetic energy into potential energy d. Stored in starch or glycogen for later use by the cell e. Released when the ATP molecules are hydrolyzed

B. Lost as heat, in accordance with the second law of thermodynamics

An endergonic reaction could be described as one that a. Proceeds spontaneously with the addition of activation energy b. Produces products with more free energy than the reactants c. Is not able to be catalyzed by enzymes d. Releases energy e. Produces ATP for energy coupling

B. Produces products with more free energy than the reactants

Spongy layer (mesophyll)

Below palisades. More loosely arranged with labyrinth of air spaces through which carbon dioxide and oxygen circulate around the cells and up to the palisade region

Non-competitive inhibitors (allosteric inhibition)

Bind to another part of an enzyme changing the function and shape of active site

Competitive inhibitors

Bind to the active site of an enzyme, competing with the substrate

Allosteric control

Binding of a regulatory molecule to a protein at one site that affects the function of the protein at a different site

Allosteric

Binds to enzyme, some place other than active site

Which bond in ATP is likely to break? by what chemical mechanism is the bond broken?

Bonds between phosphate groups broken by hydrolysis

Cyclic or non-cyclic: ATP produced

Both

Cyclic or non-cyclic: Photosystem I involved

Both

Cyclic or non-cyclic: Uses ADP and Pi as reactants

Both

Cyclic or non-cyclic: Uses NADP+ as a reactant

Both

Vein

Branches throughout mesophyll. Brings xylem and phloem into close contact with photosynthetic tissue

Which line in the diagram indicates the activation energy of the noncatalyzed reaction?

C

What is meant by an induced fit? a. The binding of the substance is an energy-requiring process b. A competitive inhibitor can outcompete the substrate for the active site c. The binding of the substrate changes the shape of the active site, which can stress or bend substrate bonds d. The active site creates a microenvironment ideal for the reaction e. The binding of an activator to an allosteric site induces a more active form of the subunits of an enzyme

C. The binding of the substrate changes the shape of the active site, which can stress or bend substrate bonds

The formation of ATP from ADP and inorganic phosphate a. Is an exergonic process b. Transfers the phosphate to an intermediate that becomes more reactive c. Produces an unstable energy compound that can drive cellular work d. Has a AG of -7.3 kcal/mol under standard conditions e. involves the hydrolysis of a phosphate bond

C. Produces an unstable energy compound that can drive cellular work

Catabolic and anabolic pathways are often coupled in a cell because a. The intermediates of a catabolic pathway are used in the anabolic pathway b. Both pathways use the same enzymes c. The free energy released from one pathway is used to drive the other pathway d. The activation energy of the catabolic pathway can be used in the anabolic pathway e. Their enzymes are controlled by the same activators and inhibitors

C. The free energy released from one pathway is used to drive the other pathway

According to the first law of thermodynamics, a. For every action there is an equal and opposite reaction b. Every energy transfer results in an increase in disorder or entropy c. The total amount of energy in the universe is conserved or constant d. Energy can be transferred or transformed, but disorder always increases e. Potential energy is converted to kinetic energy, and kinetic energy is converted to heat

C. The total amount of energy in the universe is conserved or constant

In cooperativity, a. A cellular organelle contains all the enzymes needed for a metabolic pathway b. A product of a pathway serves as a competitive inhibitor of an enzyme early in the pathway c. A molecule bound to the active site of one subunit of an enzyme affects the active site of other subunits d. The allosteric site is filled with an activator molecule e. The product of one reaction serves as the substrate for the next reaction in intricately ordered metabolic pathways

C. A molecule bound to the active site of one subunit of an enzyme affects the active site of other subunits

Why does C4 photosynthesis require more ATP than does C3 photosynthesis?

C4 fixation is an elaboration of the more common C3 carbon fixation. There are more chemical steps in this process and therefore it requires more ATP to complete the process. C3 is a more efficient means of carbon fixation.

Stomata closing creates a problem because _______cannot get into cells and _______accumulates because it can not get out

CO2 O2

Energy is defined as.....

Capacity to cause change

4 examples of accessory pigments

Carotenoids-orange Xanthophylls-yellow Phycobilins-blue and red Anthocyanins-blue and red

Induced-fit molecules

Caused by entry of substrate, the change in shape of the active site of an enzyme so that it binds more snugly to the substrate

Where does the Calvin Cycle take place in a C4 plant?

Chloroplast

Reflected light

Color we see

Reaction center

Complex of proteins associated with a special pair of chlorophyll a molecules and a primary electron acceptor. Located in a photosystem, triggers light reactions of photosynthesis

Substrate and active site must be _______to each other to _______together -Fit like______

Complimentary Bind Puzzle pieces

Intermediates

Compounds formed between the beginning and end of a metabolic pathway

Mesophyll

Consists of parenchyma cells specialized for photosynthesis

Energy is.....

Constant (1st law of thermodynamics)

Energy is neither....

Created nor destroyed (1st law of thermodynamics)

Which line in the diagram indicates the AG of the enzyme-catalyzed reaction L-M+N?

D

When amino acids join to form a protein, which of the following energy and entropy changes apply? a. -AH, +AS, +AG b. -AH, -AS, +AG c. -AH, +AS, +AG d. +AH, -AS, +AG e. -AH, +AS, -AG

D. +AH, -AS, +AG

An enzyme raises which of the following parameters? a. AG b. AH c. The free energy of activation d. The speed of a reaction e. The equilibrium of a reaction

D. The speed of a reaction

Outside of the optimal temperature and pH an enzyme will......

Denature and cease to function

Stroma

Dense fluid within the chloroplast surrounding the thylakoid membrane and containing ribosomes and DNA; involved in the synthesis of organic molecules from carbon dioxide and water

Wavelength

Distance between crests of waves, such as those of the electromagnetic spectrum

A negative AG means that a. The quantity G of energy is available to do work b. The reaction is spontaneous c. The reactants have more free energy than the products d. The reaction is exergonic e. All of the above are true

E. All of the above are true

When substance A was added to an enzyme reaction, product formation decreased. The addition of more substrate did not increase product formation. From this we conclude that substance A could be a. Product molecules b. A cofactor c. An allosteric enzyme d. A competitive inhibitor e. A noncompetitive inhibitor

E. A noncompetitive inhibitor

Which of the following characteristics is most directly responsible for the specificity of a protein enzyme? a. Its primary structure b. Its secondary and tertiary structures c. The shape and characteristics of its allosteric site d. Its cofactors e. The R groups of the amino acids in its active site

E. The R groups of the amino acids in its active site

In an experiment, changing the pH from 7 to 6 resulted in an increase in product formation. From this we could conclude that a. The enzyme became saturated at pH 6 b. The enzyme's optimal pH is 6 c. This enzyme works best at a neutral pH d. The temperature must have increased when the pH was changed to 6 e. The enzyme was in a more active shape at pH 6

E. The enzyme was in a more active shape at pH 6

Light is a form of.....

Electromagnetic energy which travels in waves

How is ATP produced by cyclic electron flow?

Electrons begin at acceptor molecule and are passed to an electron transport chain. This ETC, like the one connecting the 2 photosystems, is a series of receptor molecules able to pass along electrons but the flow is from ps I directly back tp ps 1. Electrons begin at acceptor molecule for ps I and wind up back as ps 1 again. As the electrons slide along this chain of receptor molecules in cyclic electron flow, they lose energy. This energy is in stored in ATP molecules. Eneergy from electrons involved in cyclic electrons flow is used to produce ATP.

Exergonic or endergonic: The products of a chemical reaction have more energy than the reactants

Endergonic

Chemical energy

Energy available in molecules for release in a chemical reaction; a form of potential energy

Endergonic reactions

Energy goes in to build molecules

Exergonic reactions

Energy goes out to break down molecules

Potential energy is.....

Energy matter possesses because of its location or structure such as arrangement of electrons in bonds between atoms -chemical potential

Kinetic energy is....

Energy of motion such as light and heat

ATP/ADP cycle

Energy released by breakdown reactions in the cell is used to phosphorylate ADP, regenerating ATP. Chemical potential energy stored in ATP drives most cellular work.

G-3-P

Energy-rich molecule produced in the calvin cycle

Electromagnetic spectrum

Entire spectrum of electromagnetic radiation, ranging in wavelength from less than a nanometer to more than a kilometer

Some energy converted to heat as in....

Entropy

Transformed energy results in increasing disorder called.....

Entropy

The electron is....

Excited to the primary acceptor

Exergonic or endergonic: Burning wood at a campfire

Exergonic

Exergonic or endergonic: Glucose and oxygen produce carbon dioxide, and water plus energy

Exergonic

Exergonic or endergonic: The reactants of a chemical reaction have more energy than the product

Exergonic

Exergonic or endergonic: The reaction releases energy

Exergonic

Cells need to use energy given off from an _________ reaction to start _______reactions _______is used to couple these reactions

Exergonic Endergonic ATP

Thylakoid

Flattened membranous sac inside a chloroplast. Thylakoids often exist in stacks called grana that are interconnected. Their membranes contain molecular machinery used to convert light energy to chemical energy

When a pigment absorbs light, it......

Goes from a ground state to an excited state which is unstable

System with high free energy: Work capacity

Great work

Chlorophylls

Green pigment located in membranes within the chloroplasts of plants and algae and in the membranes of certain prokaryotes. Participates directly in light reactions, which convert solar to chemical energy - Absorb violet-to blue and red wavelengths; the reason leaves appear green

This energy is later used to pump....

H+ across the membrane and produce ATP

Chemical equilibrium

In a chemical reaction, the state in which the rate of the forward reaction equals the rate of the reverse reaction, so that the relative concentrations of the reactants and products do not change with time

Light reaction occur....

In the grana

Carbon fixation

Initial incorporation of carbon from CO2 into an organic compound by an antorophic organism

Most photosynthesis occurs...

Inside the chloroplasts located in the mesophyll of the leaves

Energy may be....

Kinetic or potential

System with low free energy: Work capacity

Less work capacity

Photosystems

Light capturing unit located in thylakoid membrane at chloroplast membrane of some prokaryotes, consisting of a reaction center complex surrounded by numerous light harnessing complexes I and II absorb light at different wavelengths

Cyclic/noncyclic.....

Light reactions

Calvin cycle is...

Light-independent reaction

Enzymes

Macromolecule serving as a catalyst, a chemical agent that increases the rate of a reaction without being consumed by the reaction. Most enzymes are proteins. - speed up metabolic reactions by lowering activation energy -proteins (usually) that catalyze reactions

Energy carriers

Mainly ATP; donate energy to reactions

Chemical reaction

Making and breaking of chemical bonds, leading to changes in the composition of matter

Transport proteins

Membrane-bound substances that adjust concentration gradients in ways that influence the direction of metabolic reactions

Catabolism

Metabolic pathway that releases energy by breaking down complex molecules to simpler molecules

Most reactions occur in orderly sequences called.... Each reaction is mediated by an......

Metabolic pathways Enzyme

Regulation of enzyme activity helps control.....

Metabolism

Feedback inhibition

Method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway -end product shuts down the pathway -end product comes back and binds to one of the enzymes in the pathway stopping it from functioning

Stomata

Microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant

NonCyclic electron flow produces..... is ________what occurs

NADPH, ATP, and O2 Usually

Cyclic or non-cyclic: Produces a net gain of water as a product

Neither

Cyclic or non-cyclic: Uses CO2 as a reactant

Neither

Cyclic or non-cyclic: NADPH produced

Non cyclic

Cyclic or non-cyclic: Causes H+ to be shunted into the thylakoid compartments from the stroma

Noncyclic

Cyclic or non-cyclic: Photosystem II involved

Noncyclic

Cyclic or non-cyclic: Produces H+ by breaking apart H2O

Noncyclic

Cyclic or non-cyclic: Produces O2 as a product

Noncyclic

Cyclic or non-cyclic: Uses water as a reactant

Noncyclic

P1, P2, P3: Produces H2O as a product

None

System with high free energy: Equilibrium

Not at equilibrium

System with low free energy: Spontaneous

Not spontaneous

Palisades layer (mesophyll)

One or more layers of elongated parenchyma cells on upper part of leaf

Chloroplasts

Organelle found in plants and photosynthesis protists that absorb sunlight and use it to drive synthesis of organelle compounds from carbon dioxide and water - The two stages of photosynthesis occur here

Degradative pathways (catabolic)

Organic compounds are broken down in stepwise reactions

Coenzymes

Organic molecule serving as a cofactor. Most vitamins function as coenzymes in metabolic reactions

Heterotrophs

Organisms that obtain organic food molecules by eating other organisms or substances derived from them

P1, P2, P3: Produces PGA

Phase 1: CO2 fixation alone

P1, P2, P3: Requires CO2 as a reactant

Phase 1: CO2 fixation alone

P1, P2, P3: Requires RuBP as a reactant

Phase 1: CO2 fixation alone

P1, P2, P3: Produces G3P

Phase 2: Production of G3P

P1, P2, P3: Produces NADP+ as a reactant

Phase 2: Production of G3P

P1, P2, P3: Requires NADPH as a reactant

Phase 2: Production of G3P

P1, P2, P3: Produces ADP as a product

Phase 2: Production of G3P Phase 3: Regeneration of RuBP

P1, P2, P3: Produces Pi as a product

Phase 2: Production of G3P Phase 3: Regeneration of RuBP

P1, P2, P3: Requires ATP as a reactant

Phase 2: Production of G3P Phase 3: Regeneration of RuBP

P1, P2, P3: Requires G3P as a reactant

Phase 3: Regeneration of RuBP

Cyclic electron flow: when ATP is in low supply....

Photoexcited electrons take on alternative path

High levels of oxygen in leaves triggers_________ This decreases the plants _______

Photorespiration CO2

Chlorophyll a and b absorb red/blue wavelengths of light. these are the wavelengths they're using for.....

Photosynthesis

Why is neither O2 nor NADPH generated by cyclic electron flow?

Photosystem II is not used. Not enough energy to produce NADPH. O2 is apart of photolysis in PS II.

Chlorophyll b and carotenoids

Pigments that transfer energy to chlorophyll a

C4 plants

Plant in which the Calvin Cycle is preceded by reactions that incorporate CO2 into 4-carbon compound, the end product of which supplies CO2 for the Calvin Cycle

C3 plants

Plant that uses the Calvin Cycle for the initial steps that incorporate CO2 into organic material, forming a 3-carbon compound as the first stable intermediate

Electron transport systems

Process in which the NADH and [FADH2] produced during glycolysis, β-oxidation, and other catabolic processes are oxidized thus releasing energy in the form of ATP. The mechanism by which ATP is formed in the ETC is called chemiosmotic phosphorolation.

Catalytic cycle of an enzyme: Step 5

Products released from active site

Xylem

Provides waters and minerals from roots

Photons

Quantum or discrete quantity of light energy that behaves as if it were a particle - Packets of energy that have an undulating motion through space

Absorption spectrum

Range of a pigment's ability to absorb various wavelengths of light; also a graph of such a range

Substrates (reactants)

Reactant on which an enzyme works -substances able to enter into a reaction

Light dependent reactions

Reactions of photosynthesis that use energy from light to produce ATP and NADPH

Phycobilins

Red and blue pigments

Guard cell

Regulate opening and closing of the pore (stoma)

The absorption spectra of chloroplasts pigments provides clues to the........

Relative effectiveness of different wavelengths for driving photosynthesis

1/2 O2 is....

Released from leaf

Water then splits.......

Replacing the electrons that just left the photosystem

RuBP

Ribulose biphosphate, carboxylase, the enzyme that catalyzees the first step of the Calvin Cycle (addition of CO2 to RuBP)

Rubisco

Ribulose biphosphate, carboxylase, the enzyme that catalyzees the first step of the Calvin Cycle (addition of CO2 to RuBP)

Autotrophs

Self-feeders. Sustain themselves without eating anything derived from other living beings. Produce organic molecules from CO2 and other materials from environment. Ultimate sources of organic compounds. Almost all plants are.

Epidermis

Single tissue, layer of tightly packed cells

Cofactors

Small molecules and metal ions that assist enzymes or serve as carriers

Biosynthetic pathways (anabolic)

Small organic molecules are assembled into larger organic molecules

Active sites

Specific region of an enzyme that binds the substrate and that forms the pocket in which catalysis occurs

light dependent is.....

Splitting water

System with high free energy: Spontaneous

Spontaneous

System with low free energy: Stability

Stable

Thylakoid membrane or stroma: Carbon dioxide provides the carbon

Stroma

Thylakoid membrane or stroma: Light-independent reactions

Stroma

Thylakoid membrane or stroma: NADPH delivers the hydrogen received from water

Stroma

Thylakoid membrane or stroma: Sugars are assembled

Stroma

Pigments

Substances that absorb or reflect visible light - molecules that can absorb light

Catalytic cycle of an enzyme: Step 4

Substrates are converted into products

Catalytic cycle of an enzyme: Step 1

Substrates enter active site, enzyme changes shape so its active site embraces the substrates (induced fit)

Catalytic cycle of an enzyme: Step 2

Substrates held in active site by weak interactions such as hydrogen bonds and ionic bonds

Parts of ATP molecule

Sugar ribose Nitrogenous base adenine Chain of three phosphate groups

Phloem

Sugars and other organic products loaded into phloem for transport to other parts of plants

End products

That which is produced as the final result of an activity/process, especially the finished article in a manufacturing process

Activation energy

The amount of energy that reactants must absorb before a chemical reaction will start - Every chemical reaction between molecules involves both bond breaking and bond forming. This takes energy - The activation energy E sub A, is the initial amount of energy needed to start changing the bonds - E sub A is often supplied in the form of heat from the surroundings in a system

The electrons move through....

The electron transport chain

At the end of the electron transport chain......

The electrons enter photosystem I

Kinetic energy

The energy associated with the relative motion of objects. Moving matter can perform work by imparting motion to other matter

Potential energy

The energy that matter possess as a result of its location or spatial arrangement

Main idea of light reactions

The light reactions convert solar energy to the chemical energy of ATP and NADPH

Chlorophyll a

The main pigment of photosynthesis

Calvin cycle

The second of two major stages in photosynthesis involving fixation of atmospheric CO2 and reduction of fixed carbon into carbohydrate

Granum

The site of the first stage of photosynthesis

What happens to stomata on hot dry days? Why?

The stomata closes to conserve water. Limits access to CO2

H+ are stored in......

The thylakoid space

Each time they move,....

They lose a little energy

How can C4 plants successfully utilize the Calvin Cycle in hot, dry conditions when C3 plants would be undergoing photorespiration?

They pump CO2 into bundle sheath cells, keeping the CO2 concentration in the bundle sheath cells, keeping the CO2 concentration in the bundle sheaths high enough for RuBisco to fix CO2 rather than oxygen to minimize photo respiration

Thylakoid membrane or stroma: ATP production

Thylakoid membrane

Thylakoid membrane or stroma: Granum

Thylakoid membrane

Thylakoid membrane or stroma: Light-dependent reactions

Thylakoid membrane

Thylakoid membrane or stroma: Oxygen is formed

Thylakoid membrane

Thylakoid membrane or stroma: Sunlight energy is absorbed

Thylakoid membrane

Thylakoid membrane or stroma: The coenzyme NADP+ picks up liberated hydrogen and electrons

Thylakoid membrane

Thylakoid membrane or stroma: Water molecules are split

Thylakoid membrane

Thylakoid membrane or stroma: Where the first stage of photosynthesis proceeds

Thylakoid membrane

A cell's metabolic pathways must be.....

Tightly regulated

A molecule binds....

To the enzyme and stabilizes it in an active form

Heat

Total amount of kinetic energy due to the random motion of atoms or molecules in a body of matter; also called thermal energy. Heat is energy in its most random form

Metabolism

Totality of an organism's chemical reactions, consisting of catabolic and anabolic pathways, which manage the material and energy resources of the organism

Phosphorylation

Transfer of a phosphate group to a molecule

Oxidation-reduction reaction

Transfer of one or more electrons from one reactant to another. Loss of electrons from one substance is oxidation. Addition of electrons to another substance is reduction.

Energy may be.....

Transformed

Leaf hair

Trichomes, hairlike outgrowths of the shoot epidermis. -reduce water loss and reflect excess light -provides defense against insects

System with high free energy: Stability

Unstable

Only photosystem I is.... and only _____is produced

Used and only ATP is prodcued

Absorbed light

Used for photosynthesis

Calvin cycle main idea, occurs in the _____

Uses ATP and NADPH to convert CO2 to sugar -occurs in the stroma

CAM plants

Uses Crassulacean acid metabolism, an adaptation for photosynthesis in arid conditions. In this process, CO2 entering open stomata during the night is converted to organic acids, which release CO2 for Calvin Cycle during day, when stomata are closed

Violet-blue-green-yellow-red

Visible light portion of the electromagnetic spectrum

Light reactions split ____, release _____, produce_____ and form ______

Water Oxygen ATP NADPH

Anthocyanins

Water soluble pigments located in the vacuole that give red, purple, blue and pale yellow colors to berries, grapes, apples, red cabbage, radishes, eggplant

Cuticle

Waxy covering on stems/leaves that prevents water loss

We see these other pigments in leaves when.....

Weather gets cooler and color breaks down. Other pigments don't break down

They are missing out on any energy from the......

Yellow and orange wavelengths of light

Chloroplasts can make carbohydrate in the dark if provided with, a. ATP, NADPH, and CO2 b. an artificially induced proton gradient c. organic acids or four-carbon compounds d. a source of hydrogen e. photons and CO2

a. ATP, NADPH, and CO2

Photosynthesis is a redox process in which, a. CO2 is reduced and water is oxidized b. NADP+ is reduced and RuBP is oxidized c.CO2, NADP+, and water are reduced d. O2 acts as an oxidizing agent and water acts as a reducing agent e. G3P is reduced and the electron transport chain is oxidized

a. CO2 is reduced and water is oxidized

Oxidative phosphorylation a. respiration b. photosynthesis c. both respiration and photosynthesis d. neither respiration nor photosynthesis

a. respiration

Reduction of NAD+ a. respiration b. photosynthesis c. both respiration and photosynthesis d. neither respiration nor photosynthesis

a. respiration

Reduction of oxygen a. respiration b. photosynthesis c. both respiration and photosynthesis d. neither respiration nor photosynthesis

a. respiration

A spectrophotometer can be used to measure, a. the absorption spectrum of a substance b. the action spectrum of a reaction c. the amount of energy in a photon d. the wavelength of visible light e. the efficiency of photsynthesis

a. the absorption spectrum of a substance

Again light excites the electron to a primary acceptor......

and then passes the electron to NADP+ to form NADPH -2 electrons bond NADP+ to H+

Accessory pigments within chloroplasts are responsible for, a. driving the splitting of water molecules b. absorbing protons of different wavelengths of light and passing that energy to P680 or P700 c. providing electrons to the reaction-center chlorophyll after photoexcited electrons pass to NADP+ d. pumping H+ across the thylakoid membrane to create a proton-motive force e. anchoring chlorophyll a within the reaction center

b. absorbing protons of different wavelengths of light and passing that energy to P680 or P700

In the chemiosmotic synthesis of ATP in a chloroplast, H+ diffuses through the ATP synthase, a. from the stroma into the thylakoid space b. from the thylakoid space into the stroma c. from the intermembrane space into the matrix d. from the cytoplasm into the intermembrane space e. from the matrix into the stroma

b. from the thylakoid space into the stroma

Reduction of CO2 a. respiration b. photosynthesis c. both respiration and photosynthesis d. neither respiration nor photosynthesis

b. photosynthesis

Six molecules of G3P formed from the fixation of 3CO2 in the Calvin cycle are used to produce, a. three molecules of glucose b. three molecules of RuBP and one G3P c. one molecule of glucose and four molecules of 3-phosphoglycerate d. one G3P and three four-carbon intermediates e. none of the above, because three molecules of G3P result from three turns of the Calvin Cycle

b. three molecules of RuBP and one G3P

Chemiosmotic synthesis of ATP a. respiration b. photosynthesis c. both respiration and photosynthesis d. neither respiration nor photosynthesis

c. both respiration and photosynthesis

A difference between electron transport in photosynthesis and respiration is that in photosynthesis, a. NADPH rather than NADH passes electrons to the electron transport chain b. ATP synthase releases ATP into the stroma rather than into the cytosol c. light provides the energy to push electrons to the top of the electron chain, rather than energy from the oxidation of food molecules d. an H+ concentration gradient rather than a proton-motive force drives the phosphorylation of ATP e. Both a and c are correct

c. light provides the energy to push electrons to the top of the electron chain, rather than energy from the oxidation of food molecules

The chlorophyll known as P680 has its electron "holes" filled by electrons from, a. photosystem i b. photosystem ii c. water d. NADPH e. accessory pigments

c. water

Light independent reactions

calvin cycle 2nd stage of photosynthesis, occurs in stroma Set of reactions in photosynthesis that do not require light; energy from ATP and NADPH us used to build high-energy compounds such as sugar; also called the Calvin Cycle

How many turns of the Calvin Cycle does it take to produce one molecule of glucose? a. 1 b. 2 c. 3 d. 6 e. 12

d. 6

Which of the following processes or structures is mismatched with its location? a. light reactions- grana b. electron transport chain- thylakoid membrane c. Calvin cycle- stroma d. ATP synthase- double membrane surrounding chloroplast e. splitting of water- thylakoid space

d. ATP synthase- double membrane surrounding chloroplast

Which of the following statements is false? a. When isolated chlorophyll molecules absorb photons, their electrons fall back to ground state, giving off heat and light b. Accessory pigments, cyclic electron flow, and photorespiration may all contribute to photoprotection, protecting plants from the detrimental effects of intense light c. In the cyclic electron flow of purple sulfur bacteria, the electron transport chain pumps H+ across a membrane, creating a proton-motive force used in ATP synthesis d. In both photosynthetic prokaryotes and eukaryotes, ATP synthase catalyze the production of ATP within the cytosol of the cell e. In sulfur bacteria, H2S is the hydrogen (and this electron) source for photosynthesis

d. In both photosynthetic prokaryotes and eukaryotes, ATP synthase catalyze the production of ATP within the cytosol of the cell

In C4 plants, a. initial carbon fixation takes place in the mesophyll cells b. photorespiration requires more energy than it does in C3 plants c. the Calvin cycle, which takes place in the bundle-sheath cells, uses PEP carboxylase instead of rubisco because of its greater affinity for CO2 d. a and b are correct e. a and c are correct

d. a and b are correct

Rubisco, a. reduces CO2 to G3P b. regenerates RuBP with the aid of ATP c. combines electrons and H+ to reduce NADP+ to NADPH d. adds CO2 to RuBP in the carbon fixation stage e. transfers electrons from NADPH to 1, 3-phosphoglycerate to produce G3P

d. adds CO2 to RuBP in the carbon fixation stage

How does cyclic electron flow differ from linear electron flow? a. no NADPH is produced by cyclic electron flow b. no O2 is produced by cyclic electron flow c. the cytochrome complex in the electron transport chain is not involved in cyclic electron flow d. both a and b are correct e. a, b, and c are correct

d. both a and b are correct

Oxidation of NADP+ a. respiration b. photosynthesis c. both respiration and photosynthesis d. neither respiration nor photosynthesis

d. neither respiration nor photosynthesis

In green plants, most of the ATP for synthesis of proteins, cytoplasmic streaming, and other cellular activities comes directly from, a. photosystem I b. photosystem II c. the Calvin Cycle d. oxidative phosphorylation e. photophosphorylation

d. oxidative phosphorylation

Both NADPH and ATP from the light reactions are needed, a. in the carbon fixation stage to provide energy and reducing power to rubisco b. to regenerate three RuBP from five G3P c. to combine two molecules of G3P to produce glucose d. to reduce 3-phosphoglycerate to G3P e. to reduce the H+ concentration in the stroma and contribute to the proton-motive force

d. to reduce 3-phosphoglycerate to G3P

A photosystem may have 200-300 .......

different pigment molecules

Linear electron flow along with chemiosmosis in the chloroplast results in the formation of.... a. ATP only b. ATP and NADPH c. ATP and G3P d. ATP and O2 e. ATP, NADPH, and O2

e. ATP, NADPH, and O2

Which of the following substances is/are the final electron acceptors for the electron transport chains in the light reactions of photosynthesis and in cellular respiration? a. O2 in both b. CO2 in both c. H2O in the light reactions, and O2 in respiration d. P700 and NAD+ in the light reactions, and NAD+ or FAD in respiration e. NAD+ in the light reactions, and O2 in respiration

e. NAD+ in the light reactions, and O2 in respiration

CAM plants avoid photorespiration by, a. keeping their stomata closed during the day b. performing the Calvin cycle at night c. fixing CO2 into four-carbon compounds in the mesophyll, which then release CO2 in the bundle-sheath cells d. storing water in their succulent stems and leaves e. fixing CO2 into organic acids during the night, which then provide CO2 during the day

e. fixing CO2 into organic acids during the night, which then provide CO2 during the day

Which of the following parts of an illuminated plant cell would you expect to have the lowest pH? a. nucleus b. cytosol c. chloroplast d. stroma of chloroplast e. thylakoid space

e. thylakoid space

Each enzyme has an......

optimal temperature and pH in which it can function

When a photon of light excites a pigment it generally ......

passes it on to a neighboring pigment

it donates an electron to an electron acceptor molecule that......

starts the electron transport system

A chlorophyll a is.....

the reaction center

What happens to the absorbed energy? Energy flows randomly among pigments of a photosystem until......

trapped by reaction center