Bio 311C Sata Exam 3

What happens when a suitable substrate binds to an enzyme?

The active site amino acids bond with the substrate

Cyanide binds to cytochrome oxidase at a site where the substrate oxygen would normally bind. This is an example of

competitive inhibition

an example of a catabolic reaction is

lactate fermentation

what is an anabolic process that is endergonic and endothermic?

CH₄ +2O₂ → CO₂ + 2H₂O

ATP yields 7.3 kcal/mol of free energy and it is coupled with many enzyme reactions that would not otherwise happen. Which can be coupled with ATP hydrolysis to become a spontaneous reaction? A reaction with a G value of _______?

5

which process occurs under both aerobic and anaerobic conditions

glycolysis

what is the key regulatory enzyme in glycolysis inhibited by the accumulation of first committed product of the Krebs cycle?

phosphofructokinase

in this reaction NADH + Pyruvate → NAD⁺ + Lactate, Pyruvate becoming lactate, is a/an _______________ process and _______________ is the OXIDIZING or REDUCING agent.

reduction, NADH, REDUCING

the outputs of Krebs cycle that transfer energy to the electron transport system are

FADH₂ and NADH

the output of glycolysis include ATP, ____________, and _____________

NADH and pyruvate

Which poison can inhibit the generation of delta [H⁺]?

A chemical that would make the inner mitochondrial membrane leaky to ions

lack of oxygen during cellular respiration will inhibit Krebs Cycle and Acetyl CoA formation inside mitochondria, even though oxygen is not an input in such processes because under anaerobic conditions

Water is not formed

each FADH₂ produces less ATP when compared to NADj in oxidative phosphorylation because ______________________

FADH₂ gives electrons at a lower energy level to the ETC and hence makes less ATP

What is not directly associated with photosystem II?

calvin cycle

th parts of plant tissue, namely ______________ & ______________ allow transport of water and sugar respectively.

xylem and phloem

when the phosphorylation occurs during least reactions, the pH of the thylakoid space will _______________ compared to the equilibrium state during night time

decrease as the protons are pumped into the thylakoid

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 process?

synthesis of ATP

when a suspension of algal cells is incubated in a flask in the presence of light and CO₂ and then transferred to the dark, the release if oxygen stops. this reaction stops when the algal suspension is placed in the dark because

the reaction needs light

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 CO2 more 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

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. What is the possible reason for this result?

modified enzyme lost to the binding to both O₂ and CO₂

why is it important to reduce the chromosome numbers to half the original each time for sexual reproduction of animals?

when the sperm and egg cells they double the chromosome number and so we need to half the chromosome number in the gametes

The homologous chromosomes separate during ____________________ and their sister chromatids separate during _____________ phase of meiosis.

anaphase I & anaphase II

the phases of meiosis that cause the most variation in the four daughter cells are

prophase I & metaphase I

chromosome number is reduced to half the original number during meiosis because

half of the chromosomes from each gamete are lost during fertilization

what does not occur during mitosis?

crossing over between homologous chromosomes

label the following examples as "exergonic or endergonic" and "exothermic or endothermic" based on the changes in free energy and enthalpy respectively in each of them

A. Simple Diffusion

B. Protein synthesis

C. Burning Fossil Fuels

D. ATP hydrolysis

E. Starch synthesis

A. exergonic & exothermic

B. endergonic & endothermic

C. exothermic & exergonic

D. exergonic & exothermic

E. endergonic & endothermic

ATP Hydrolysis yields 7.3 Kcal/mol free energy and it is coupled with many enzyme reactions that would not otherwise happen. Which of the following reaction can be coupled with ATP hydrolysis to become a favorable or spontaneous reaction. A reaction with a ΔG value of _______ Kcal/mol.

A)

-5.8

B)

4.3

C)

10.5

D)

-5.3

E)

7.3

B)

4.3

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. From this information, we can say that

substrate B is less effective than substrate A to have same amount of products

formed

The energy released in aerobic respiration is originally derived from ________________.

the food we eat

The reaction as shown below, with reference to FAD, is a __________________ process and ___________ is the (oxidizing or reduction)

FAD + X-H₂ → FADH₂ + X

reduction; X-H2; reducing

The reaction shown below is a/an __________________________ and it occurs during the process of _________________ .

substrate level phosphorylation; glycolysis

The energy is stored in the form of ________ in food

covalent bonds

The energy to make ATP in oxidative phosphorylation comes from ________.

NADH

More free energy is released during the Krebs cycle than during glycolysis, but only 2 molesof 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

reduce NAD⁺ and FAD

When mice were fed with radioactive carbon in glucose (C₆H₁₂O₆) all the 6 CO₂ molecules will be released during which of the following process

Acetyl CoA formation and Krebs cycle

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

Which of the following statement is not true of glycolysis?

A)

ATP is used to prime the process

B)

ATP is made in this process.

C)

Acetyl CoA is an output of glycolysis

D)

NADH is produced

E)

Pi from cytoplasm is used to make ATP

C)

Acetyl CoA is an output of glycolysis (made in the cytoplasm)

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

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?

oxidative phosphorylation

FADH2 produces less ATP each when compared to NADH because _________________

FADH2 allows fewer protons transported across inner membrane and hence makes less ATP

The inputs of non-cyclic photophosphorylation, include light, water and ___________

NADP+ and ADP, Pi

Which parts or tissues of a plant allow transport of water and sugar respectively?

Xylem and phloem

When does cyclic electron flow (at Photosystem I) important for photosynthesis?

When there is abundance of NADPH

Which of the following is NOT directly associated with photosystem II?

Oxidative phosphorylation

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?

The synthesis of ATP

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

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.

When the phtophosphorylation is happening during light reactions, the pH of stroma will ______________ compared to the equilibrium state during night time.

increase as the protons are pumped into thylakoid

Bacteria typically have _______, whereas eukaryotes have _______.

one chromosome that is circular; many chromosomes that are linear

Which of the following statements about mitosis is true?

A)

The chromosome number in the resulting cells is halved.

B)

DNA replication is completed in prophase.

C)

Crossing over occurs during prophase.

D)

Two genetically identical daughter cells are formed.

E)

It consists of two nuclear divisions.

D)

Two genetically identical daughter cells are formed.

Centrosomes are made of _________ and they ______________.

centrioles; determine the plane of cell division

A chemical inhibitor that blocks the initiation of DNA replication is added to actively dividingcells. Most of the cells would be found in their ____ phase of their cell cycle.

G1

The initiation of the S phase and the M phase of the cell cycle depends on _______ and _______ to make _______.

A)

actin; myosin; fibers.

B)

Cdk; cyclin; MPF.

C)

ligand; enzyme; complex.

D)

insulin; receptor; G-protein.

E)

ADP; Pi; ATP.

B)

Cdk; cyclin; MPF.

Which of the following statements about mitosis is NOT true?

independent assortment happens in metaphase

How is the chromosome number of each daughter cell reduced to half the original amount during meiosis?

A)

Chromosomes do not replicate during the interphase I preceding prophase I.

B)

Chromosomes replicate only once before meiosis I but the cell divides twice.

C)

Half of the chromosomes from each gamete are lost during fertilization.

D)

Sister chromatids separate during anaphase I but not in anaphase II of meiosis.

E)

Chromosome numbers are reduced to half during crossing over in prophase I.

B)

Chromosomes replicate only once before meiosis I but the cell divides twice.

Why is it important to reduce the chromosome numbers in half for sexual reproduction of humans?

A)

We do not need that many chromosomes and less is better.

B)

Skin cells and liver cells are sensitive to increased chromosome number.

C)

The sperm and egg cells start with double the chromosome number before fertilization.

D)

The sperm and egg cells fertilize and double the chromosome number.

E)

If we continue to half the chromosome number in meiosis then we will need a small set of chromosomes after evolution.

D)

The sperm and egg cells fertilize and double the chromosome number.

The daughter cells become haploid after ____________________ phase of meiosis.

anaphase I

Non-disjunction (unequal separation) of sister chromatids possibly resulting in many genetic disorders happens during ______________of meiosis.

anaphase II

Which of the following in an anabolic process that is endergonic and endothermic?

A)

ATP + H2O → ADP + Pi

B)

C6H12O6 + 6O2 → 6CO2 + 6H2O

C)

CO2 + H2O → CH2O + O2

D)

FADH2 → FAD + H2

E)

CH4 + 2O2 → CO2 + 2H2O

C)

CO2 + H2O → CH2O + O2

What represents potential energy?

chemical bonds, water in a dam, charged battery

What is the relation between exergonic and exothermic reactions?

exothermic reactions can also be exergonic processes

The free energy change of a system is: ∆G = ∆H - T ∆S. Which of the following is incorrect?

a positive ∆H and negative ∆S can make ∆G negative

melting of an ice at room temperature results in the following changes in free energy, enthalpy and entropy

-ΔG, +ΔH, +ΔS

What happens when a suitable substrate binds to an enzyme?

the active site amino acids bond with the substrate

Cyanide binds to cytochrome oxidase at a site where the substrate oxygen would normally bind. This is an example of

competitive inhibition

an example of a catabolic reaction is

lactate fermentation

what is an anabolic process that is endergonic and endothermic?

CH4 +2O2 → CO2 + 2H2

which process occurs under both aerobic and anaerobic conditions

glycolysis

what is the key regulatory enzyme in glycolysis inhibited by the accumulation of first committed product of the Krebs cycle?

phosphofructokinase

in this reaction NADH + Pyruvate → NAD⁺ + Lactate, Pyruvate becoming lactate, is a/an _______________ process and _______________ is the OXIDIZING or REDUCING agent.

reduction, NADH, reducing

the outputs of Krebs cycle that transfer energy to the electron transport system are

FADH₂ and NADH

the output of glycolysis include ATP, ____________, and _____________

NADH and pyruvate

Which poison can inhibit the generation of delta [H⁺]?

A chemical that would make the inner mitochondrial membrane leaky to ions

lack of oxygen during cellular respiration will inhibit Krebs Cycle and Acetyl CoA formation inside mitochondria, even though oxygen is not an input in such processes because under anaerobic conditions

Water is not formed

each FADH₂ produces less ATP when compared to NADj in oxidative phosphorylation because _____________________

FADH₂ gives electrons at a lower energy level to the ETC and hence makes less ATP

What is not directly associated with photosystem II?

calvin cycle

the parts of plant tissue, namely ______________ & ______________ allow transport of water and sugar respectively.

xylem and phloem

when the phosphorylation occurs during least reactions, the pH of the thylakoid space will _______________ compared to the equilibrium state during night time

decrease as the protons are pumped into the thylakoid

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 process?

synthesis of ATP

when a suspension of algal cells is incubated in a flask in the presence of light and CO₂ and then transferred to the dark, the release if oxygen stops. this reaction stops when the algal suspension is placed in the dark because

the reaction needs light

chromosome number is reduced to half the original number during meiosis because

half of the chromosomes from each gamete are lost during fertilization

what does not occur during mitosis?

crossing over between homologous chromosomes

label the following examples as "exergonic or endergonic" and "exothermic or endothermic" based on the changes in free energy and enthalpy respectively in each of them

A. Simple Diffusion

B. Protein synthesis

C. Burning Fossil Fuels

D. ATP hydrolysis

E. Starch synthesis

A. Simple Diffusion: exergonic & exothermic B. Protein synthesis: endergonic & endothermic C. Burning Fossil Fuels: exothermic & exergonic D. ATP hydrolysis: exergonic & exothermic E. Starch synthesis: endergonic & endothermic

C3 plants

Calvan cycle, No c4 pathway, During daytime, low water efficiency, Rice

C4 plants

Calvan cycle, C4 pathway, During the daytime, Med-High water efficiency, corn

CAM plants

Calvan cycle (Daytime), C4 pathway (Nighttime, Both in mesophyll cell), High water efficiency, cacti

Glycolysis location

Cytoplasm

Glycolysis inputs

NAD+, Glucose, ADP and Pi

Glycolysis outputs

Pyruvate, NADH, ATP

Glycolysis regulatory enzymes

Hexokinase, PFK (phosphofructose kinase)

Acetyl CoA Formation Location

cytoplasm to matrix

Acetyl CoA Formation inputs

Pyruvate, CoA, NAD+

Acetyl CoA Formation Outputs

CO2, Acetyl CoA, NADH

Acetyl CoA Formation Enzyme

Pyruvate dehydrogenase

Kreb's cycle location

matrix

Kreb's cycle inputs

FAD, NAD+, ADP and Pi, Acetyl CoA, H2O

Kreb's cycle outputs

CO2, NADH, FADH2, ATP, CoA

Kreb's cycle enzyme

Citrate synthase, isocitrate dehygrogenase

Oxidative phosphorylation location

Inner mitochondrial matrix

Oxidative phosphorylation inputs

NADH, FADH2, ADP and Pi, O2