BIO EXAM 3

How does the reduction of pyruvate to lactate during fermentation allow glycolysis to continue in the absence of oxygen? A) Water is formed during this reaction. B) This reaction is an endergonic reaction. C) This reaction is coupled to the oxidation of NADH to NAD+. D) This reaction is coupled to the formation of ADP and Pi. E) This reaction is coupled to the reduction of NAD+ to NADH.

C) This reaction is coupled to the oxidation of NADH to NAD+. -would be oxidation since there's a loss of electron/hydrogen In muscle cells, NAD+ is regenerated by converting the pyruvate into lactate which returns to the liver to be reconverted to glucose for later use.

Which parts or tissues of a plant allow transport of water and sugar respectively? A) Stoma and xylem B) Leaf and stem C) Xylem and phloem D) Phloem and xylem E) Chloroplast and mitochondrion

C) Xylem and phloem water-Xylem elements in veins help transport water and minerals. sugar-large and small veins contain phloem to transport sugars

When a suspension of algae is incubated in a flask in the presence of light and CO2 and then transferred to the dark, the reduction of 3-phosphoglycerate to glyceraldehyde 3-phosphate is blocked. This reaction stops when the algae are placed in the dark because A) the reaction requires CO2. B) the reaction is exergonic. C) the reaction requires ATP and NADPH D) the reaction requires O2. E) chlorophyll is not synthesized in the dark.

C) the reaction requires ATP and NADPH ATP and NADH during the light reactions and are used in the Calvin cycle. ATP needed because the Calvin cycle reaction is endergonic and NADPH is needed for reduction.

What is the single most important chemical bond that supplies energy for the majority of the transportation we use today and what process make such bond?

C-H bonds• Generated by photosynthesis to fix CO2 to make carbohydrate, which is then converted to other organic molecules.

Jane Doe ate a cheese burger. Select three molecules from this meal that will provide energy and list the process in which each molecule from this burger would enter the process of respiration.

Carbohydrates from bun: Enter at glycolysis, form pyruvate, will go through Acetyl CoA formation, Krebs cycle and oxidative phosphorylation. Fat from meat and cheese: Enter at Acetyl CoA formation by beta oxidation process and then Krebs cycle followed by oxidative phosphorylation. Proteins meat and cheese: Amino acids will need to be deaminated and then enter Krebs cycle followed by oxidative phosphorylation.

When does cyclic electron flow (at Photosystem I) occur instead of non-cyclic electron flow? A) When there is abundant ATP. B) When there is shortage of NADPH. C) When there is shortage of ATP. D) When there is abundance of NADPH. E) When there is equal amount of ATP and NADPH

D) When there is abundance of NADPH. EXP: cyclic electron flow can only be in photosystem 1 while non-cyclic in Bothe PS 1 and PS 2 -occurs only in primitive plants and when NADPH is derived from the pathways and when NADPH is abundant and NADP+ is limiting (i.e. in a high NADPH/NADP+ environment).

When RuBisCO enzyme was modified to reduce the binding of oxygen to minimize photorespiration, the enzyme activity to fix CO2 to carbohydrate was also decreased. A possible explanation to this result is A)carbon fixation reaction requires O2. B)modified enzyme prefers O2 and not CO2. C)modified enzyme prefers CO2 and not O2. D) modified enzyme lost the binding to both O2 and CO2. E) carbon fixation reaction requires light and water.

D) modified enzyme lost the binding to both O2 and CO2. -CO2 decreases as it is fixed in the Calvin cycle. O2 increases as a result of light reactions (PS II). RUBISCO has the same active (binding) site for O2 and CO2. -When you decrease O2 binding, you also reduce CO2 binding

Develop a hypothesis as to why cells use ATP as their main energy source. How will you test this hypothesis?

Hypothesis: ATP structure is compatible with the enzyme active site and enzymes could use the energy released by ATP hydrolysis. Test ATP, GTP, TTP and UTP with different enzymes that use ATP for energy coupling

Label the oxidation, reduction, oxidizing agent and reducing agent in this diagram. NAD+ + X-H2 <--> NADH + X + H+

- reduction process (end product has more hydrogens/electrons) -h2 is an oxidizing agent since its accepting hydrogen

The action spectrum is broader than the absorption spectrum because

-The action spectrum is the result of all the pigments harvesting the light energy. - The absorption spectrum depicts the relative amount of light absorbed by the individual pigments.

select all the answer choices that describe the process of respiration -exergonic process -exothermic process -catabolic process -anabolic process -exergonic process

-exergonic process -exothermic process -catabolic process -exergonic process

why does oxidative phosphorylation make so much more ATP (32-34 ATP/ glucose) compared to Substrate Level Phosphorylation (2+ATP/Glucose)?

-oxidative phosphorylation utilizes all the NADH and FADH2 generated in - glycolysis -Acetyl CoA Formation -Krebs cycle to make a lot of ATP EX: This is the major aerobic process to generate ATPs for cellular energy. This occurs in mitochondria of eukaryotic cells, specifically in the inner membrane and the intermembrane space. In prokaryotes, it occurs on the plasma membrane.

understand the given equation and answer the following question pyruvate CoA+NAD+----> Acetly CoA+Co2+NADH this reaction of NAD+ is becoming NADH, is considered a/an_______ and the NAD+ acts as an _____ agent

-reduction -oxidizing -theres a gain in electrons/hydrogen which means it is a reduction process RIG ( reduction=gain) -NAD+ acts as an oxidizing agent since it is accepting electrons/hydrogen

If the Keq of a reaction is 10, when you increase the substrate concentration 2 fold, the Keq will _______________________

-stay the same EXP: at equilibrium *keq* the substrate concentration of reactants and products will stay the same

Which of the following are essential to perform glycolysis? Select all that apply. A) Glucose B) NAD+ C) ADP D) Pi (inorganic phosphate) E) NADH F) ATP G) Oxygen

A) Glucose B) NAD+ C) ADP D) Pi (inorganic phosphate) F) ATP glycolysis (Inputs) Glucose + 2 NAD+ + 2 ADP + 2 Pi (Outputs) 2 Pyruvate + 2 NADH + 2 H+ + 2 ATP (net)

CAM plants can keep stomata closed in daytime, reducing water loss. This is possible because they __________. A) fix CO2 into organic acids during the night by PEP carboxylase B) use photosystems I and II during day and night. C) use the enzyme phosphofructokinase, to fix CO2more effectively D) fix CO2 into sugars in the bundle-sheath cells. E) fix CO2 into pyruvic acid in the mesophyll cells.

A) fix CO2 into organic acids during the night by PEP carboxylase EXP: PEP carboxylase has no O2 affinity even when the CO2 levels go down during the hot sunny weather, the CO2 fixation continues and photorespiration is minimized -in CAM plants C4 occurs in the night C4 plants-bundle-sheath cells and mesophyll cells

The following reaction, with reference to FAD, is a __________________ process and FAD is a/an ______________(oxidizing or reducing) agent. FAD + X-H2 --> FADH2 + X A) reduction.... ...oxidizing B) oxidation........reducing C) reduction... ...reducing D) oxidation.... ...oxidizing E) oxidation ...oxidizing

A) reduction.... ...oxidizing E: This is the correct answer. FAD is gaining H+ and e- (being reduced by X-H2) and it is oxidizing X-H2 reduction process =oxidizing agent (accepts hydrogen/electrons) oxidation process= reducing agent (donates electrons) hydrogen=electrons

Equilibrium is a stage when the ΔG is zero, i.e. there is no net change or the forward and reverse reactions are the same. If you consider an enzyme reaction, the products are formed from the substrate (same as reactant in a chemical reaction). Keq is calculated as the number of products formed per unit substrate at equilibrium. Consider the following example as 1:1 ratio of reactant to product and calculate the Keq. A. At equilibrium, the reactant remaining was 200 μg/ml and product was 800 μg/ml B. A reaction was started with 80 mM substrate ending with 60 mM product at equilibrium

A. 4 A + B (reactants) ---> C + D (products) Keq = [C] x [D] / [A] x [B] products/reactants= 800/200=4 B. 3 A+B=C+D 80= 60+x x=20 products/reactants= 60/20=3

what is the exergonic process that directly drives the endergonic process of ATP synthesis in oxidative phosphorylation? A. chemiosmosis and proton motive force B. Reduction of NAD+ and NADH C. Generation of proton concentration gradient D. ATP hydrolysis releasing -7.3 Kcal/mol E.Consumption of O2 to accept the electrons at the end of respiration

A. A. chemiosmosis and proton motive force EX: This process is best explained by the chemiosmotic theory proposed by Peter Mitchell. According to this hypothesis, NADH or FADH2 electron carriers transfer the electrons stripped from food molecules. These electrons are then transferred through a series of membrane proteins known as the electron transport chain and are finally accepted by O2. During this electron transfer process, H+s are pumped from the matrix into the intermembrane space of mitochondria generating a [H+] gradient. A membrane protein complex ATP-synthase generates ATP by combining ADP with inorganic phosphate (Pi). When the H+s return into the matrix through ATP synthase they release the tightly bound ATP. -The H+s returning to the matrix due to their concentration gradient is called proton motive force.

Any accidental drinking of methanol can make one blind or cause death. A person who drank methanol by mistake is given ethanol as an antidote. Shown below is the enzyme reaction of Alcohol Dehydrogenase (ADH) on these two substrates. Ethanol + ADH --> Acetaldehyde Methanol + ADH --> Formaldehyde How does this treatment work? A. ADH prefers ethanol and acetaldehyde can be converted to a non-toxic molecule. B. Acetaldehyde can be converted to a non-toxic molecule and ADH prefers methanol C. Formaldehyde can be converted to a non-toxic molecule and ADH prefers methanol D. Ethanol is an activator and methanol is an inhibitor of ADH Methanol is an activator and ethanol is an inhibitor

A. ADH prefers ethanol and acetaldehyde can be converted to a non-toxic molecule.

Which of the following is an example of an exergonic reaction (1st example) that powers the synthesis of an endergonic reaction (second example)? A. ATP hydrolysis and photosynthesis B. ATP synthesis and protein synthesis C. ATP hydrolysis and simple diffusion D.Simple diffusion and active transport

A. ATP hydrolysis and photosynthesis ATP hydrolysis is the breakdown of ATP using water which is an exergonic reaction resulting in the process of photosynthesis which is and endergonic reaction.

Creatine phosphate is used as a supplement during intense workouts. the reaction shown below illustrates what happens in the muscle cell deprived of oxygen. This reaction is a/an______ and its catalyzed by_____ creatine phosphate+ ADP---> Creatine+ATP A. Substrate level phosphorylation...Kinase B. Reduction...Kinase C. Oxidation... Kinase D. Substrate level phosphorylation... ATP synthase E. Oxidative phosphorylation.... ATP synthase

A. Substrate level phosphorylation...Kinase EX: substrate level phophorylaiton is the Synthesis of ATP by transferring a phosphate from a high-energy phosphate compound to ADP (adenosine diphosphate) by enzymes generally known as kinases

Sliced potatoes and apples easily bruise and become brown. This is due to an enzyme called catecholase that makes catechol to protect the sliced parts from bacterial infection. What can you do to prevent this bruising and browning?

Adding lemon juice, salt and keeping in the refrigerator (lowering temperature) can slow down or stop this browning. E: First, high temperature denatures proteins and kills cells. -Second, heat would speed up all reactions, not just those that are needed. -Each enzyme has an optimal temperature at which its reaction rate is greatest -Just as each enzyme has an optimal temperature, it also has a pH at which it is most active. The optimal pH values for most enzymes fall in the range of pH 6-8, an acidic environment denatures most enzymes, but pepsin is adapted to maintain its functional three-dimensional structure in the acidic environment of the stomach.

What factors make one person be able to drink more alcohol than others? Use the biochemical reaction, Ethanol + ADH à Acetaldehyde to explain your answer.

At least two variations of ADH genes produce faster production of acetaldehyde, which is rapidly metabolized by ALDH2. However, about 40% of Asian people (Japanese, Chinese, and Koreans) have an inactive ALDH2 mutation that results in much higher acetaldehyde levels after drinking than normal which prevents it from being converted to a non toxic molecule at a fast rate.

ATP hydrolysis yields a ΔG of -7.3 Kcal/mol free energy and it is coupled with many enzyme reactions that would not otherwise happen. Which of the following reactions can be coupled with ATP hydrolysis to become a favorable or spontaneous reaction. A reaction with a ΔG value of _______ Kcal/mol. A) -7.8 B) 4.3 C) 10.5 D) -5.3 E) 7.3

B) 4.3 E: Since ATP hydrolysis provides 7.3 Kcal/mol, the endergonic reaction that needs 4.3 Kcal (less than 7.3) can be coupled to become spontaneous. TB: Since ATP hydrolysis is a thermodynamically favorable exergonic reaction, it can be coupled with endergonic reactions that are not spontaneous. For example, the reaction Glucose + Fructose ---> Sucrose + H2O (∆G = + 6.5 kcal/mol) is not spontaneous because of + ∆G, so an ATP is used to drive this reaction forward.

Which of the following processes utilize the ATP made through oxidative phosphorylation in plant mitochondria? A) Photosynthesis in chloroplast B) Endergonic processes inside cytoplasm C) DNA synthesis in nucleus D) Osmosis E) Facilitate diffusion

B) Endergonic processes inside cytoplasm -endergonic processes use up energy, absorbing it to build a bigger molecule.

When we exercise for a long time without rest, the muscle cells become deprived of oxygen. Which of the following is not produced in a muscle cell under such conditions? A) NADH B) Ethanol C) ATP D) Pyruvate. E) Lactate.

B) Ethanol EX: We do not make ethanol because we cannot perform alcohol fermentation. Animals do not have pyruvate decarboxylase and the accumulation of ethanol is toxic, so they perform lactic acid fermentation in the muscle cells to regenerate NAD+ during O2 deprivation. In muscle cells, NAD+ is regenerated by converting the pyruvate into lactate which returns to the liver to be reconverted to glucose for later use.

Which output of Glycolysis will enter the next step of Acetyl CoA formation? A) ATP B) Pyruvate C) ADP D) NADH E) Ethanol

B) Pyruvate (2 pyruvate) glycolysis (Inputs) Glucose + 2 NAD+ + 2 ADP + 2 Pi (Outputs) 2 Pyruvate + 2 NADH + 2 H+ + 2 ATP (net)

During light reactions, where does the synthesis of ATP and NADPH occur in a plant cell? A) Cytoplasm B) Stroma side of thylakoid membrane of chloroplast C) Inner membrane of chloroplast D) Matrix of mitochondrion E) Inner membrane of mitochondrion

B) Stroma side of thylakoid membrane of chloroplast light reactions happen in the thylakoid membrane while the Calvin cycle happens in the stroma where ATP and NADPH (the products of light reaction) are transported to

An enzyme was tested with two different substrates A and B resulting in products X and Y. The Km for substrate A was 10 mM and the Km for substrate B was 100 mM. Which of the following statement is correct? A) Substrate A is less effective than substrate B to have same amount of products formed. B) Substrate B is less effective than substrate A to have same amount of products formed. C) There is no difference between A and B in terms of products formed. D) X is produced less than Y with same amount of substrate used. E) Y is produced at same level as X with same amount of substrate used.

B) Substrate B is less effective than substrate A to have same amount of products formed. EX: Lower the Km the stronger the fit or reaction with a higher products formed. A lower Km means Vmax is achieved faster making substrate A the more effective enzyme.

When the photophosphorylation is happening during light reactions, the pH of stroma will ______________ compared to the equilibrium state during night time. A) decrease as the protons are pumped back from thylakoid. B) increase as the protons are pumped into thylakoid. C) stay neutral as the protons will balance the influx and efflux D) decrease first and then increase gradually. E) stay neutral as the photophosphorylation will not affect the pH in stroma.

B) increase as the protons are pumped into thylakoid. photophosphorylation is the proton gradient inside thylakoid which becomes acidic ph decreases while ph in stroma increases.

During photophosphorylation, the pH of the thylakoid interior will be _______________ A) higher than the pH of stroma since protons move into thylakoid B) lower than the pH of stroma since protons move into thylakoid space. C) same as the the pH of stroma since protons go in and out of thylakoid space D) higher than the pH of stroma since protons move into stroma from thylakoid space

B) lower than the pH of stroma since protons move into thylakoid space. Protons move into the thylakoid space from stroma resulting in a lot of protons inside thylakoid meaning a lower PH

Photosynthesis reactions are summarized below in the given equation. 6CO2 + 6H2O + light → C6H12O6 + 6O2 Which of the following changes will occur in this process with respect to free energy, enthalpy, and entropy. A) +ΔG, +ΔH, +ΔS B) +ΔG, -ΔH, +ΔS C) +ΔG, +ΔH, -ΔS D) -ΔG, +ΔH, +ΔS

C) +ΔG, +ΔH, -ΔS since this is an anabolic reaction ( when simple molecules are created into big ones) there will be not net free energy, which means it will have a positive delta G = less spontaneous (less stable) and an increase in enthalpy ( delta H)since it is not being released as heat, there will be negative entropy since energy is not being released (low spontaneous)

Which of the following is an anabolic process that is endergonic and endothermic? A) ATP + H2O → ADP + Pi B) C6H12O6 + 6O2 → 6CO2 + 6H2O + energy C) CO2 + H2O + light → CH2O + O2 D) FADH2 → FAD + H2 E) CH4 + 2O2 → CO2 + 2H2O

C) CO2 + H2O + light → CH2O + O2 EX: This is a summary of photosynthesis making carbohydrate from CO2 using light energy. Hence endergonic, endothermic and anabolic. -Photosysnthesis is an anabolic pathway, which consumes energy to build complicated molecules from simpler ones; -they are called biosynthetic pathway the simple pathways in this case would be the Carbon dioxide, water, and light to make a more complicated molecule in this case a carbohydrate.

Which of the following is an exergonic process that directly helps the endergonic process of ATP synthesis in oxidative phosphorylation? A) Acetyl CoA formation B) Ethanol fermentation C) Chemiosmosis D) Glycolysis E) Substrate level phosphorylation

C) Chemiosmosis EX: ATP synthase actually uses the movement of the protons from the intermembrane space back into the matrix (chemiosmosis) as energy to allow it to make ATP from ADP and Pi. EXP: OP: approximately 3-4 protons are needed to make and transport 1 ATP. Since NADH and FADH2 result in the transport of approximately 10 and 6 protons respectively, they result in making 3 and 2 ATPs each respectively.

The energy to make ATP in oxidative phosphorylation comes from food via ___________. A) FAD and NAD+. B) ADP and Pi. C) NADH and FADH2. D) ATP and GTP. E) Water and O2.

C) NADH and FADH2. NADH or FADH2 electron carriers transfer the electrons stripped from food molecules

Which of the following is NOT directly associated with photosystem II? A) Release of oxygen. B) Harvesting of light energy by chlorophyll and other pigments C) Oxidative phosphorylation. D) Reaction center chlorophyll E) Splitting of water.

C) Oxidative phosphorylation. EXP: photosystem 2 releases 1/2 o2 from split of H2O (does not occur in P1) -light energy is harvested and used to excite electrons to the reaction center chlorophyll -water splits- 1/2 O2 and 2 H+used for ATP synthase when pumped out to stroma producing ATP

Why can we not buy ATP in HEB or Walmart?

It is made naturally -anabolic process ADP+pi+energy <=> ATP+H2O

Why visible light (wavelength of 400 to 700 nm) alone is useful in photosynthesis and not the high energy UV or long wavlength IR spectrucm of light? Answer in one or two words.

It is the optimal energy level and safe range of visible light spectrum. Also, it is the most abundant wavelength of light

Why do plants require light to perform photosynthesis?

Just as energy was needed to concentrate protons in the intermembrane space of the mitochondria during respiration, energy is also needed to concentrate protons in the thylakoid space of the chloroplasts. However, in photosynthesis, we use electromagnetic energy in the form of light to drive the process by exciting the electrons in the reaction center and making it go through the electron transport chain. In both cases, protons are being concentrated to power ATP synthase via chemiosmosis.

The C4 plants are efficient in using water because they _______________ _____________________________

Minimize photorespiration. -photorespiration happens during dry days when stomata pores close up to conserve water moisture, the Co2 levels fall and O2 rises thus rubisco fixes O2 to release more Co2 until CO2 levels are back to normal. However in C4 plants photorespiration is overcome with the use of Pep carboxylase which has no affinity for O2 so even when CO2 goes down during hot weather CO2 is continued to be fixed and photorespiration is minimized.

What is/are the main purpose(s) of respiration?

The main purpose of respiration is to make ATP. In addition, the metabolites generated in respiration are used to make other molecules needed by the organism.

in the TV show "The Biggest Loser", John Doe exercised hard every day and kept a strict diet enough to meet his daily calorie needs and lost 20 pounds in 2 months. Where did the 20 pounds go and in what form?

This mass left the body as CO2 in breath and H2O in breath and urine.

Why is visible light important for photosynthesis and not the higher energy UV or lower energy infrared radiation?

Visible light is not only abundant and has the right energy level that does not damage the cells and has sufficient energy to excite electrons to generate proton concentration gradient and make ATP.

Why do we eat?

We consume molecules by eating food. These molecules are broken down to make ATP and also to build our body.

You had a big breakfast, which included eggs, bacon, pancakes and orange juice. List three major types of biological molecules that you consumed in this big breakfast and specify the process in which each of them will be used to make ATP in your body through aerobic respiration.

eggs- proteins in eggs. Amino acids will need to be deaminated and then enter Krebs cycle followed by oxidative phosphorylation. bacon-fat from bacon enter at Acetyl CoA formation by beta oxidation process and then Krebs cycle followed by oxidative phosphorylation. orange juice- carbs (monosaccharides)- Enter at glycolysis, form pyruvate, will go through Acetyl CoA formation, Krebs cycle and oxidative phosphorylation.

Calvin cycle needs ATP because it is a/an ___________________ process.

endergonic -its using up energy which will always be an anabolic/ endergonic process

The primary function of light energy in photosynthesis is to ____________________ .

excite electrons in the reaction center chlorophyll. when pigment molecule absorbs photon energy transferred from each pigment molecule within the light harvesting complex until passed onto chlorophyll A which boosts their electrons to a higher energy level (proportional to the energy level of the photons received) AND transfer it to a different molecule-primary electron acceptor, which is a molecule capable of accepting electrons and becoming reduced.

4. List two examples for each of exergonic, endergonic, exothermic and endothermic reactions in biology.

exergonic-osmosis, cellular respiration, ATP hydrolysis ( breakdown of ATP) endergonic- active transport, photosynthesis, making ATP exothermic-burning fossil fuels endothermic- ice melting -exothermic are reactions that increase the heat of the surroundings are classified as exothermic reactions, whereas the ones that do not change the temperature of the surroundings are exergonic (change in are energy) -endothermic is a relative change in enthalpy, whilst endergonic refers to the relative change in free energy of a system.

What is an example of a reaction that is spontaneous but results in a decrease of entropy within the system?

freezing water ΔH- positive ΔS- positive ΔG- negative at higher temperatures, positive at lower temperatures EXP: positive delta s mean decrease in entropy while negative delta S means an increase

How many times the Calvin-Benson cycle should occur to make a single glucose molecule?

6

Melting of ice at room temperature results in the following changes in free energy, enthalpy, and entropy. A) +ΔG, +ΔH, +ΔS B) +ΔG, -ΔH, +ΔS C) +ΔG, -ΔH, -ΔS D) -ΔG, +ΔH, +ΔS E) -ΔG, +ΔH, -ΔS

D) -ΔG, +ΔH, +ΔS For a reaction to have a negative ∆G, the system must lose free energy during the change from initial state to final state. -Because it has less free energy, the system in its final state is less likely to change and is therefore more stable than it was previously -Ice melting consumes energy from the surroundings to melt. Also, the energy in liquid water is more than the ice. so it will be negative free energy. + H because heat Is being absorbed, -G free energy I seeing released, free energy released means + s ( entropy) ΔH- negative ΔS- negative ΔG- always negative *** ΔH- positive ΔS- positive ΔG- negative at higher temperatures, positive at lower temperatures ΔH- negative ΔS- negative ΔG- negative at lower temperatures, positive at higher temperatures ΔH- positive ΔS- negative ΔG- always positive

Which outputs of light reactions enter Calvin-Benson cycle? A) ATP B) NADPH C) O2 D) A and B E) A, B and C

D) A and B

The inputs of non-cyclic photophosphorylation, include light, water and ___________ A) NADP+. B) ADP, Pi C) CO2 D) A and B E) A, B and C

D) A and B the electrons from PS 1 are used to reduce NADP+ to generate NADPH. ATP is generated from ADP+pi products are ADP and NADPH

How is the light energy converted to chemical energy in light reactions of photosynthesis?

when a photochemically excited special chlorophyll molecule of the reaction center loses an electron, undergoing an oxidation reaction. EXP: The light reactions also gener- ate ATP, using chemiosmosis to power the addition of a phosphate group to ADP, a process called photophosphorylation. Thus, light energy is initially converted to chemical energy in the form of two compounds: NADPH and ATP. NADPH, a sourceof electrons, acts as "reducing power" that can be passed along to an electron acceptor, reducing it, while ATP is the versatile energy currency of cells.

Given the equation for free energy change as ΔG = ΔH - TΔS, list three conditions that would result in the reaction to become spontaneous (same as exergonic or favorable).

ΔH- negative ΔS- negative ΔG- always negative ΔH- positive ΔS- positive ΔG- negative at higher temperatures, ΔH- negative ΔS- negative ΔG- negative at lower temperatures

What are the limiting factors of photosynthesis? List three major factors related to the structure and function of cell structures or components that limit the photosynthetic efficiency.

1. Light 2. Water 3. CO2 levels 4. Temperature Cell structures: C3 plants- requires photorespiration when CO2 levels are low O2 is fixed with RUBP until CO2 levels are back to normal. C4 plants- photorespiration is minimized so CO2 levels have no impact as PEP carboxylase is what is used to fix Co2 into 4-C sugars w/ enzyme pep carboxylase. in C4 plants, the C3 pathway is limited to bundle sheath cells (cells adjacent to veins or vascular bundles) and the C4 pathway is limited to mesophyll cells (closer to the surface). CAM plants- same as C4 plants w/ C3 and C4 cycles fixing the CO2 into 4-sugars and then 3-sugars however these pants don't have the limiting factor to different cells but instead occur in the same cell with C3 limited during day when temps are higher and C4 during night when temps are cooler

A reaction was started with 40 mM substrate and it reached equilibrium in 2 hours. At equilibrium, the product concentration was 30 mM. Assuming a 1:1 ratio of substrate to product, what is the Keq in this reaction?

3 (C)(D)(products)/(A)(B) (reactants) 30+X (products) =40 (reactants) X=10 Keq= 30mM/10mM Keq=3 -The higher Keq, the faster the reaction occurs. -Keq and ∆G are not related but one can expect a reaction with higher Keq to be favorable with a - ∆G.

The second law of thermodynamics states that every energy transfer and transformation results in increased randomness in the universe. Living organisms consume energy and release energy. They transfer and transform various forms of energy but they still maintain structure and order. Despite this, living organisms do not become more random or disorganized. This can occur because A. The randomness happens in their surroundings B. They do not follow the laws of thermodynamics C. They are closed system and nothing can change in a closed system D. They are open systems but can be exception to the second law of thermodynamics. E. Living organisms can continue to transform energy forever without becoming disorganized.

A. The randomness happens in their surroundings EXP: The entropy of a particular system, such as an organism, may actually decrease as long as the total entropy of the universe—the system plus its surroundings—increases. -Thus, organisms are islands of low entropy in an increasingly random universe. The evolution of biological order is perfectly consistent with the laws of thermodynamics.

Label the following examples as exergonic or endergonic, exothermic or endothermic and if entropy increases or decreases (within the system) based on the changes in free energy, enthalpy and entropy respectively. A. Osmosis B. Active transport C. Respiration D. Photosynthesis E. Amino acid biosynthesis

A. osmosis- when particles diffuse they go from more free energy to less free energy when they diffuse meaning its EXERGONIC, exothermic, increases, -ΔG, -ΔH (or ΔH=0), and +ΔS B. active transport. uses energy so it will be an anabolic process aka endergonic, endothermic +ΔG, +ΔH, -ΔS C.respiration catabolic reaction -Cellular respiration is analogous to this system: Glucose is broken down in a series of exergonic reactions that power the work of the cell. The product of each reaction is used as the reactant for the next, so no reaction reaches equilibrium. -ΔG, -ΔH, and +ΔS D. Photosynthesis +ΔG, +ΔH, and -ΔS anabolic process-six carbon dioxide molecules and six water molecules, are converted by light energy captured by chlorophyll (implied by the arrow) into a sugar molecule and six oxygen molecules, the products. E.Amino acid biosynthesis +ΔG, +ΔH, and -ΔS Anabolic process meaning positive free energy ( no energy released), not spontaneous (negative), absorbs heat instead of releasing it

What is the purpose of the electron shuttle in the respiration process? A. To carry electrons from cytoplasmic NADH to mitochondrial FAD or NAD+ B. To carry electrons from cytoplasm to extracellular matrix C. To transfer electrons from cytoplasm to chloroplast for photosynthesis light reactions D. To electrons are transferred from NAD+ to NADH E. The electrons can be damaging to the cell and they should be sent to peroxisome for degradation

A.To carry electrons from cytoplasmic NADH to mitochondrial FAD or NAD+ The 2 pyruvates from glycolysis are transferred into mitochondria by a specific transport protein. The 2 ATPs made are used in the cytoplasm. In aerobic respiration, the NADH transfers its electrons to a mitochondrial- FAD or NAD+ to be used in the electron transport chain

More free energy is released during the Krebs cycle than during glycolysis, but only 2 moles of ATP is produced for each mole of glucose undergoing glycolysis. Most of the remaining free energy that is produced during the Krebs cycle is used to _______________________ A) synthesize GTP. B) reduce NAD+ and FAD. C) release as heat. D) oxidize pyruvate. E) make ethanol.

B) reduce NAD+ and FAD. EX: Krebs cycle produces NADH and FADH2, which is used for oxidative phosphorylation (Outputs) of Krebs cycle 2 CO2 + 3 NADH + 3H+ + FADH2 + ATP + CoA -electron transfer, protons are pumped out of matrix (Krebs cycle) into inter membrane space -NADH transfers the electrons to NADH-Q reductase and gets reduced to NAD+ which returns to the mitochondrial NAD+ pool to accept electrons from the Krebs cycle. -FADH2 transfers electrons at a lower energy level to ubiquinone (Coenzyme Q-10 or CoQ), a mobile electron carrier. FADH2 then becomes FAD and returns to Krebs cycle. Krebs cycle cannot continue without having enough NAD+ and FAD for the oxidation of acetyl CoA.

1. The energy released in aerobic respiration is originally derived from ________________. A) the CO2 we breath out B) the food we eat. C) ATP in the cell D) A and B E) A, B and C

B) the food we eat. derived from food we eat, glucose, and o2 to produce 6co2, 6 H2O, and 30-32 ATP

Overall, respiration is a/an____________________ and _______________________ A) oxidative........endergonic B) oxidative.....exergonic C) reductive.....endergonic D) reductive....exergonic E) endergonic.....redox process

B)oxidative.....exergonic Respiration is a break down process of extracting electrons from the food we eat and releasing free energy. -oxidative is breaking down process that loses electrons.

Which reaction will require ATP hydrolysis to occur? A. Endergonic reaction B. Exergonic reaction C. Both endergonic and exergonic reaction D. Neither of the reaction shown in this figure

B. Endergonic reaction EXP: ATP hydrolysis is an exergonic process which is used for an endergonic reaction (photosynthesis)

Draw a bacterial cell and eukaryotic cell (separately) showing the main components needed for aerobic respiration in each. Label the diagram (in between the two cells) and show the locations of where the glycolysis, Krebs cycle and oxidative phosphorylation occur in each of them.

BACTERIA cytoplasm: glycolysis, Krebsplasma membrane: ETC/OP. EUKARYOTA cytoplasm: glycolysis matrix: Krebs mitochondrial inner membrane: ETC/OP.

Consider the following graph and conclude the nature of the enzyme. Phosphofructokinase (PFK) is made of 4 subunits and is also a key regulatory enzyme of glycolysis. Shown below is the response of PFK to the substrate concentration (Fructose 6-phosphate). What is the nature of this enzyme and what is the role of ATP in this reaction? A. Allosteric enzyme and Inhibitor B. Allosteric enzyme and Activator C. Allosteric enzyme and cofactor D. Simple enzyme and Activator E. Simple enzyme and Inhibitor

C. Allosteric enzyme and inhibitor Fructose 6-phosphate + ATP --> Fructose 1,6-bisphosphate + ADP EXP: Step 3. Phosphorylation of fructose 6-phosphate by Phosphofructokinase (PFK; a kinase which phosphorylates a phospho-fructose). -key regulatory step-means it can make the glycolysis go faster, slower, or stop. -PFK is a complex allosteric enzyme. It is induced by high levels of ADP or AMP (means the cell needs ATP) and inhibited by high levels of ATP (means the cell has enough ATP) and citrate (the first committed product of Krebs cycle- another indication of cells having enough ATP -induced by high levels of ADP or AMP (means the cell needs ATP) and inhibited by high levels of ATP (means the cell has enough ATP)

Compare and contrast C3, C4 and CAM plants in terms of leaf anatomy, the main CO2 fixing enzyme and water use efficiency.

C3 leaf anatomy- takes place in mesophyll cell CO2 fixing- Only the Calvin cycle is used to fix CO2. uses photorespiration w/ RUBP water use efficiency-not efficient bc of use of photorespiration C4 leaf anatomy-In C4 plants, the C3 pathway is limited to bundle sheath cells (cells adjacent to veins or vascular bundles) and the C4 pathway is limited to mesophyll cells (closer to the surface). ex: corn and sugarcane CO2 fixing- C3 AND C4 used to fit Co2 and (PEP carboxylase) used which fixes CO2 into 4-C sugars -photorespiration is minimized since PEP carbolyxylase has no affinity for O2 -The C4 plants are efficient in CO2 fixation and water use efficiency. CAM plants -don't have separate cells like C4 plants but instead use C3 pathway during day and C4 pathway during the night time -both C3 and C4 cycles to fix CO2 into 4-C sugars first and thereafter into 3-C sugars. ATP and NAdh available during the day time (light reaction) while CO2 is available during night -same water and Co2 efficiency as C4 plants ex: pineapple, cacti.

What are the main inputs (reactants) required for photosynthesis? Where are they used in the overall process?

CO2: fixation of carbon into a sugar by reducing CO2. In C3 plants, carbon fixation initially happens via RubisCO. In C4 and CAM plants, PEP carboxylase fixes CO2 to ultimately form oxaloacetate.• H2O: water acts as the source of electrons for the ETC in non-cyclic light reactions. These lead to the creation of ATP and NADPH used in the Calvin Cycle. -electrons are only transported through ETC from PS II to PS I which is not present in cyclic photophosph.

Temperature, pH and salt concentration affect the enzyme activity because all of them can

Change the 3-D shape of the enzyme.

Which of the following poison dissipate Δ [H+]? A) A poison that would inhibit ATP synthase B) A chemical that would inhibit citrate synthase C) A chemical that would block the substrate level phosphorylation D) A chemical that would make the inner mitochondrial membrane leaky to ions E) A chemical that mimics glucose but is not metabolized by hexokinase

D) A chemical that would make the inner mitochondrial membrane leaky to ions The inner mitochondrial membrane is where the proton gradient is produced, which provides the energy for ATP synthase to make ATP. Making this leaky prevents the gradient from forming and no ATP can be made. 3 resp poisons Uncouplers of proton gradient: Abolish proton gradient by making the membrane leaky, resulting in no ATP synthesis. E.g. dinitrophenol (DNP). ATP synthase inhibitors: directly binds to ATP synthase and inhibit ATP synthesis. E.g. oligomycin. Electron transport inhibitors: Blocks the electron transport at various stages. resulting in reduced/lack of proton gradient and ATP synthesis but their main effect is in blocking O2 from accepting electrons stopping the regeneration of NAD+and FAD without which Krebs cycle can not function. E.g. Cyanide (CN-), carbon monoxide (CO), and azide (N3- ) all bind to cytochrome oxidase and block electron transfer to O2

When mice were fed with radioactive carbon in glucose (C6H12O6) all the 6 CO2 molecules will be released during which of the following process A) Krebs cycle and Oxidative phosphorylation B) Glycolysis and acetyl CoA formation C) Glycolysis and Krebs cycle D) Acetyl CoA formation and Krebs cycle E) Glycolysis and oxidative phosphorylation

D) Acetyl CoA formation and Krebs cycle EX: Take a look at the respiration-flowchart from class. Acetyl CoA is formed from 2 pyruvates and in the process 2 CO2 molecules are released. (1 CO2 in each turn) During Krebs, 2 CO2 released and 4 in total of the two turns

The first law of thermodynamics includes all the following except ___________________________ A) The total energy of the universe is constant B) Energy can neither be created nor destroyed C) Energy can be transferred or transformed D) Entropy increases in the universe with every energy transfer or transformation.

D) Entropy increases in the universe with every energy transfer or transformation. EX: this is the second law of thermodynamics ex: when a bear converts chemical energy of the food its eating into other forms of energy to carry out bio processes. what happens next is part of the second law of thermodynamics: Entropy increases in the universe with every energy transfer or transformation.

If someone is accidentally poisoned by methanol, ethanol is given as an antidote. How does ethanol prevent methanol poisoning? Note: Ethanol is converted to acetaldehyde by Alcohol Dehydrogenase (ADH) and methanol is converted to formaldehyde by the same enzyme. A) Ethanol binds to methanol and inactivates it B)Methanol reacts with ethanol and becomes propanol C) Ethanol is a competitive inhibitor D) Ethanol is a preferred substrate that keeps the enzyme busy in making acetaldehyde E) Methanol is a preferred substrate that keeps the enzyme busy in making formaldehyde

D) Ethanol is a preferred substrate that keeps the enzyme busy in making acetaldehyde -preferred substrates such as the ethanol in this situation allow for a lower km and v max to be achieved faster which does not allow any time for methanol to be converted to formaldehyde. Ethanol has a lower Km for this ADH and keeps the enzyme busy making acetaldehyde and let methanol be flushed out without being converted to the toxic formaldehyde.

Which of the following would slow down or inhibit key enzymes of Krebs cycle and glycolysis? A) Excess amount of ADP and Pi B) Limited amount of ATP C) Excess amount of NAD+. D) Excess amount of citrate. E) Limited amount of FADH2.

D) Excess amount of citrate. (excess amounts of citrate and ATP) Step 3. Phosphorylation of fructose 6-phosphatePhosphofructokinase of glycolysis (PFK) is the key regulatory enzyme that means it can make the glycolysis go faster, slower, or stop. This is a complex allosteric enzyme. -induced by high levels of ADP or AMP (means the cell needs ATP) -inhibited by high levels of ATP (means the cell has enough ATP) and citrate (the first committed product of Krebs cycle- another indication of cells having enough ATP).

In an enzyme-catalyzed reaction, which of the following does not change with or without enzyme? A) Reactants B) Products C) Change in activation energy D) Net change in free energy

D) Net change in free energy EX: free energy change will always remain the same with or without an enzyme. It is crucial to note that an enzyme cannot change the ∆G for a reaction; it cannot make an endergonic reaction exergonic. -An enzyme catalyzes a reaction by lowering the EA barrier

Trace the pathway of electrons all the way from glucose to O2, through cellular respiration. Include events of inter-molecular energy transfer.

During glycolysis, acetyl CoA formation, and Krebs cycle the following changes happen. "Glucose → Pyruvate → Acetyl CoA→ CO2 + Electrons + Protons" The electrons extracted in the above oxidation process at every stage are carried by NADH and FADH2 which then enter oxidative phosphorylation and ultimately given to O2 to make water. 2 electrons + 2 protons + ½ O2 = H2O

When one consumes excess amounts of carbohydrates, they gain weight and store excess energy as fat. Conversion of carbohydrates to fat will involve the intermediate _________. A) ATP. B) Starch. C) Citrate. D) NADH. E) Acetyl CoA.

E) Acetyl CoA. EX: E Look at the respiration flowchart from class (on canvas). Excess carbohydrates results in more glycolysis so acetyl-CoA will build up. Instead of going on to Krebs, the acetyl-CoA can be converted into fatty acids and fat-storage. EXP: Acetyl CoA is generated from fats which are broken down to generate energy through the Krebs cycle and oxidative phosphorylation.

Given the same concentration of substrate, which of the following reactions will yield the maximum amount of products? A) Enzyme alone B) Enzyme + substrate alone C) Enzyme + substrate + competitive inhibitor D) Enzyme + substrate + non-competitive inhibitor E) Enzyme + Substrate + Activator

E) Enzyme + Substrate + Activator Activator increases the products formed at the Km level compared with enzymes + substrate alone.

What is the relation between exergonic and exothermic reactions? A) They are typically unrelated, but can be coupled with ATP hydrolysis B) Every exothermic reaction leads to a subsequent exergonic one C) Every exergonic reaction is also an exothermic one D) Both result in a reduction of entropy in the universe E) Exothermic reactions may be endergonic or exergonic processes

E) Exothermic reactions may be endergonic or exergonic processes EX: Not D since (catabolic) exergonic, exothermic, and endergonic processes result in an increase in entropy in the universe (spontaneous process'- increase entropy in the universe) The exothermic reactions are those, in which, energy is released and delta H is negative For endergonic reactions to be exothermic, the constraint T deltas S is required to be positive and greater than the negative value of delta H thus resulting in a positive value of delta G. (endergonic) Therefore, option E is correct.

Which of the following represents potential energy? A) Chemical bonds B) Water in a dam C) Charged battery D) A and B only E) A, B and C are correct

E) The definition of potential energy states all of them as potential energy. E: Potential energy is the energy of state or position—that is, stored energy. It can be stored in many forms: in chemical bonds, as a concentration gradient, or even as an electric charge imbalance.

The energy is stored in the form of ________ in the food we eat. A) acetyl CoA B)fructose C) proteins D) ATP E) covalent bonds

E) covalent bonds The covalent bonds provide the energy needed to produce ATP in the body that can be used as energy. When food is broken down the covalent bonds release energy that was in the bonds.

The reaction shown below is a/an ___________________ and it is catalyzed by _______. Phosphoenolpyruvate + ADP --> Pyruate + ATP A) reduction.... kinase B) phosphorylation.....phosphatase C) oxidative phosphorylation.......ATP synthase D) substrate level phosphorylation.......ATP synthase E) substrate level phosphorylation.......kinase

E) substrate level phosphorylation.......kinase E: This reaction is a transfer of phosphate from PEP to ADP (substrate-to-substrate transfer) and Kinase (adds phosphate) facilitates this reaction. -Synthesis of ATP by transferring a phosphate from a high-energy phosphate compound to ADP (adenosine diphosphate) by enzymes generally known as kinases. This process, which occurs during glycolysis in the cytoplasm, generates a limited amount of ATPs. This is the only process to generate ATPs in anaerobic fermentation.

Suppose a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes? A) the absorption of light energy by chlorophyll B) the splitting of water C) the flow of electrons from photosystem II to photosystem I D) the reduction of NADP+ E) the synthesis of ATP

E) the synthesis of ATP EXP: With no separation, no proton gradient will be generated, so ATP synthase will not function, inhibiting production of ATP photophosphorylation: electrons transferred through series of thylakoids membrane proteins which generates protein gradient inside thylakoid. when protons return to storm through ATP synthase this helps in the synthesis of ATP similar to chemiosmosis in respiration.

Migratory birds store or carry limited amounts of stored energy or food but fly over long distances. Which of the following process is most utilized in such situations to make the most amount of ATP for their flying? A) Glycolysis B) Ethanol fermentation C) Lactate fermentation D) Krebs cycle E) Oxidative phosphorylation

E. Oxidative phosphorylation EX: 32-34 ATP made per glucose. So this will produce the most amount of energy for the bird. total ATP glycolysis- 2 ATP ethanol fermentation- 2 ATP Lactate fermentation- 2 ATP Krebs cycle- 2 ATP Oxidative phosphorylation- 32-34 ATP per glucose

As you add more and more substrates, the velocity of enzyme reaction increases and as it reaches above a certain point, it plateaus because of what reason? A) Enzyme is denatured and can no longer funcion effectively. B) Substrates run out and enzymes can no longer convert them to products C) All enzymes are busy catalyzing the reactions at saturating substrate concentration. D) All things need to come to an end and so are the enzyme reactions. E) Enzymes become inactive at saturating substrate concentration.

EX: Vmax is achieved when all the enzyme active sites are filled with the substrate (i.e. saturated) When substrate concentration is saturated, the velocity can not increase any more. All enzyme active sets are filled so now the enzymes are busy catalyzing the reactions at saturating substrate concentration.

Compare and contrast photophosphorylation and oxidative phosphorylation with two similarities and three differences.

Similarities: Both make ATP and use electron transport chain, proton concentration gradient and Chemiosmosis to make ATP Differences: Oxidative phosphorylation occurs in mitochondrial inner membrane, utilizes NADH/FADH2, O2 and releases NAD+/FAD and H2O. Photophosphorylation occurs on thylakoid membrane and uses light energy to make ATP

2. Compare and contrast substrate level phosphorylation with oxidative phosphorylation providing two similarities and three differences.

Similarities:• Both make ATP by combining ADP + Pi → ATP,• Couple energy from an exergonic process into the endergonic phosphorylation process. Differences:• SLP produces much less ATP compared to OP.• SLP much faster than OP.• OP requires O2, SLP happens in presence or absence of O2.

briefly describe the reduction and oxidation reactions that occur in respiration. focus only on the electron carriers/ organic cofactors, and include two processes (one for reduction and one for oxidation) in respiration. include the molecules involve din the process and their location in the eukaryotic cell.

Similarly, in the reaction, the reactant species gains electrons is referred to as the reduction reaction and during respiration, oxygen molecules get reduced. The electron carriers involved in respiration are NAD+ (nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide). During respiration, these two molecules shuttle electrons between other intermediate molecules by gaining electrons ( NADH + H+ and FADH2) from one molecule and transferring them to other molecules.

Why do plants need water?

ans: source of electrons and O2 release -O2 evolved (released) from the photosynthesis reaction comes from the splitting of a water molecule. - The release of O2 occurs during the light reactions to replenish the 2 electrons lost from photosystem II -The 2 electrons lost by the PS II after receiving photons are replaced by extracting electrons from the splitting of water

What are the connections between glycolysis, acetyl CoA formation, Krebs cycle and oxidative phosphorylation? Make a flow chart how the output of one process becomes input of another process.

glycloysis (cytoplasm)- 1 glucose+ 2 pyruvate , and 2 net ATPS Acetyl CoA (mitochondria)- Acts as substrate for Krebs cycle pyruvate from mitochondria releases CO2 and NAD+ (electron carrier) is REDUCED to NADH rig gaining electrons/h+ inhibits by high levels of acetyl CoA, NADH, GTP -induced by high levels of CoA, NAD+, GDP Krebs cycle (matrix and inner membrane of mitochondria) - 1st step preformed by citrate synthase, induced by AMP and inhibited by ATP (Inputs) Acetyl CoA + 3 NAD+ + FAD + ADP + Pi + 2H2O (Outputs) 2 CO2 + 3 NADH + 3H+ + FADH2 + ATP + CoA oxidative phosphorylation (protons pumped from matrix into inter membrane space) -Uses the NADH and FADH2 reducing to NAD+ which returns to Krebs cycle in the matrix to accept electrons since it is an oxidizing agent meanwhile the electrons lost are pumps into the intermemebrane space allowing for a decrease in Ph inside. NADH-3 ATP FADH-2 ATP total: 32-34 ATP

What are the benefits of photosynthesis to other organisms?

oxygen release

List three real life examples of how enzyme activity is affected by pH, salt concentration and temperature.

pH: Activation of hydrolytic enzymes by the low pH of stomach acid, high pH of bile, or low pH of lysosome. Entire activity of endomembrane system is governed by pH. -The optimal pH values for most enzymes fall in the range of pH 6-8, but there are exceptions. For example, pepsin, a digestive enzyme in the human stom- ach, works best at a very low pH. Such an acidic environment denatures most enzymes, but pepsin is adapted to maintain its functional three-dimensional structure in the acidic environ- ment of the stomach. In contrast, trypsin, a digestive enzyme residing in the more alkaline environment of the human intestine, would be denatured in the stomach Salt concentration: Dependence of human enzymes on correct intracellular salt concentration (too high → dehydration and death). Likewise saltwater and freshwater fish suffer shock and death if placed in salt concentrations they're not adapted to. Temperature: Freezing and refrigerating foods slows enzyme reaction rates in organisms that cause spoilage and in the food itself. Blanching (immersion in hot water) before freezing completely deactivates enzymes and further increases shelf-life. A moderate fever increases activity of immune system and causes difficulty for invading organisms. Too high of a fever will inactivate enzymes necessary for brain function causing death. Others examples include heat shock, hypothermia, etc.

Which types of plants use the C4 cycle? Which types of plants utilize the Calvin Cycle?

plants that use PEP carboxylase for initial carbon fixation form the 4-carbon compound oxaloacetate; this is the C4 cycle that is being referred to. Both C4 and CAM plants do this C4 pathway, and oxaloacetate is used as the source of CO2 for the Calvin Cycle. All plants use the Calvin Cycle to reduce CO2 into sugar molecules.

Calvin cycle needs NADPH because it is a/an _____________________ process

reduction -reduction is an endergonic process absorbing energy from ATP and NADH