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Biology · EUEE topic

Cells and biomolecules: every EUEE question 2015–2017 E.C. (54 questions), solved

54 questions · 2015 ×24 · 2016 ×19 · 2017 ×11

Cell theory, organelles, prokaryotes/eukaryotes, and the main biomolecules from EUEE Biology.

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2016 E.C.

2016 E.C. · natural · Q25 · Origin of life

The view of biochemical origin of life hypothesized that the first life-forms appeared in warm primitive ocean and were heterotrophic. Which one of the following statements can support this idea?
  1. A. The appearance of dust of unknown source with microbial spores that can feed on organic molecules.
  2. B. Life is the inherent property of the universe which permits unlimited existence through usage of resource in it.
  3. C. The formation of abundant organic molecules due to radiations and the absence of oxygen led to the primitive living organisms.
  4. D. Resistant spores from meteorites reached to the earth and used organic molecules to survive in the environment.
Worked solutionUnofficial

Answer: C

Answer C: The formation of abundant organic molecules due to radiations and the absence of oxygen led to the primitive living organisms.. The stem is: The view of biochemical origin of life hypothesized that the first life-forms appeared in warm primitive ocean and were heterotrophic. Which one of the following statements can support this idea? Letter C is the Abrari key for this Origin of life.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q71 · Enzymes

Which one of the following properties of enzymes shows their catalytic nature?
  1. A. Reducing the activation energy
  2. B. Being non-specific to substrates
  3. C. Being altered in a chemical reaction
  4. D. Changing the nature of the product
Worked solutionUnofficial

Answer: A

Answer A: Reducing the activation energy. The stem is: Which one of the following properties of enzymes shows their catalytic nature? Letter A is the Abrari key for this Enzymes.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q72 · Enzyme classification

If an enzyme is named as "EC 3.4.11.1." in a systematic naming, what does the number "3" represent?
  1. A. ultra-subclass of an enzyme that is related to the place where they act
  2. B. sub-subclass of an enzyme in relation to its protein nature
  3. C. sub-class of an enzyme in relation to the source from where it was discovered
  4. D. main class of an enzyme which indicates the type of reaction it catalyses
Worked solutionUnofficial

Answer: D

Answer D: main class of an enzyme which indicates the type of reaction it catalyses. The stem is: If an enzyme is named as "EC 3.4.11.1." in a systematic naming, what does the number "3" represent? Letter D is the Abrari key for this Enzyme classification.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q73 · Enzyme action

In the lock-and-key model of enzymatic action, the activation energy is lowered through
  1. A. straining of the substrate molecules bound to the active site
  2. B. provision of alternative pathway for the reaction
  3. C. conformational change of substrate molecules
  4. D. permanent modification of the active site of the enzyme
Worked solutionUnofficial

Answer: A

Answer A: straining of the substrate molecules bound to the active site. The stem is: In the lock-and-key model of enzymatic action, the activation energy is lowered through Letter A is the Abrari key for this Enzyme action. Enzymes strain/stress substrate bonds to lower activation energy. B (alternative pathway) is a distractor; A best fits lock-and-key.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q74 · Enzyme cofactors

Which one of the following minerals are used as cofactor for the enzyme alcohol dehydrogenase?
  1. A. Magnesium ions
  2. B. Cobalt ions
  3. C. Ferrous ions
  4. D. Zinc ions
Worked solutionUnofficial

Answer: D

Answer D: Zinc ions. The stem is: Which one of the following minerals are used as cofactor for the enzyme alcohol dehydrogenase? Letter D is the Abrari key for this Enzyme cofactors. Alcohol dehydrogenase requires zinc as cofactor.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q76 · Enzyme experiment

A student made an experiment to observe the effect of temperature on catalase of mashed potato. After three parallel trials, results showed reaction rate peaking at 30°C. At which temperature was the reaction fastest?
  1. A. 30°C
  2. B. 10°C
  3. C. 50°C
  4. D. 55°C
Worked solutionUnofficial

Answer: A

Answer A: 30°C. The stem is: A student made an experiment to observe the effect of temperature on catalase of mashed potato. After three parallel trials, results showed reaction rate peaking at 30°C. At which temperature was the reaction fastest? Letter A is the Abrari key for this Enzyme experiment. 30°C had shortest mean time (5 s) and highest rate (6.6 cm3/s).

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q81 · Biomolecules/Lipids

Which one of the following organic molecules has ester bonds in its molecular structure?
  1. A. Glycogen
  2. B. Triglyceride
  3. C. Amino acid
  4. D. Cellulose
Worked solutionUnofficial

Answer: B

Answer B: Triglyceride. The stem is: Which one of the following organic molecules has ester bonds in its molecular structure? Letter B is the Abrari key for this Biomolecules/Lipids.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q82 · Protein structure

Which one of the following statement is correct about the structural organization of hemoglobin? It is formed
  1. A. through the association of two or more polypeptide chains
  2. B. when a polypeptide chain folds itself during protein synthesis
  3. C. through folding of secondary structure of a polypeptide chain
  4. D. by hydrogen bonding between quaternary and tertiary structures
Worked solutionUnofficial

Answer: A

Answer A: through the association of two or more polypeptide chains. The stem is: Which one of the following statement is correct about the structural organization of hemoglobin? It is formed Letter A is the Abrari key for this Protein structure. Hemoglobin has quaternary structure - 4 polypeptide chains.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q83 · Lipids/Buoyancy

The presence of large amount of lipid reduces the density of an animal. Which function of triglycerides is related to this fact?
  1. A. Buoyancy
  2. B. Thermal insulation
  3. C. Waterproofing
  4. D. Respiratory substrate
Worked solutionUnofficial

Answer: A

Answer A: Buoyancy. The stem is: The presence of large amount of lipid reduces the density of an animal. Which function of triglycerides is related to this fact? Letter A is the Abrari key for this Lipids/Buoyancy.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q84 · Carbohydrate chemistry

The missing number represented by the letter "n" in the formula of maltose (C12H22O11) is
  1. A. 11
  2. B. 12
  3. C. 24
  4. D. 22
Worked solutionUnofficial

Answer: D

Answer D: 22. The stem is: The missing number represented by the letter "n" in the formula of maltose (C12H22O11) is Letter D is the Abrari key for this Carbohydrate chemistry. Question is unclear which position 'n' refers to. In C12H22O11, the hydrogen count is 22. If n = number of H, answer is 22 (D). Ambiguous without original formula layout.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q96 · Cell membrane

Which one of the following arrangement of molecules in the fluid mosaic model of the cell membrane is correct?
  1. A. Phospholipid molecules are peripherally attached to proteins
  2. B. Phospholipids fill the protein like a sandwich to retain its rigidity
  3. C. Phospholipids are inserted into the bilayer of protein molecules
  4. D. Protein molecules are studded between the phospholipid bilayers
Worked solutionUnofficial

Answer: D

Answer D: Protein molecules are studded between the phospholipid bilayers. The stem is: Which one of the following arrangement of molecules in the fluid mosaic model of the cell membrane is correct? Letter D is the Abrari key for this Cell membrane.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q97 · Cholesterol/Membrane

What is the role of cholesterol in the cell membrane? It
  1. A. reduces the fluidity of the cell membrane
  2. B. anchors integral proteins to the cytoskeleton
  3. C. acts as receptor site for hormones and other signaling molecules
  4. D. transports hydrophilic molecules into the cell
Worked solutionUnofficial

Answer: A

Answer A: reduces the fluidity of the cell membrane. The stem is: What is the role of cholesterol in the cell membrane? It Letter A is the Abrari key for this Cholesterol/Membrane. Cholesterol is a fluidity buffer; at body temperature it reduces fluidity/restrains phospholipid movement. A is the intended answer.

Unofficial — solved by Abrari, not an official EAES key.

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2016 E.C. · natural · Q98 · Cell organelles

This item is based on a table about the function of cellular organelles (Mitochondria, Golgi body, Lysosomes, Ribosomes). Which numbers in the table show the correct function of the given organelles?
  1. A. 2 and 3
  2. B. 2 and 4
  3. C. 1 and 4
  4. D. 1 and 3
Worked solutionUnofficial

Answer: A

Answer A: 2 and 3. The stem is: This item is based on a table about the function of cellular organelles (Mitochondria, Golgi body, Lysosomes, Ribosomes). Which numbers in the table show the correct function of the given organelles? Letter A is the Abrari key for this Cell organelles. Row 2 (Golgi modifies/distributes = YES) correct; Row 3 (Mitochondria = site of aerobic respiration = YES) correct. Row 1 wrongly says Golgi does protein synthesis; Row 4 wrongly says ribosomes digest foreign cells. So 2 and 3 correct = A.

📖 G9 Biology, Unit 3, §3.4, p. 60“Prokaryotic cells such as bacterial cells don’t have membrane-bound organelles or a nucleus.”

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C.

2017 E.C. · natural · Q3 · Cell biology

From the following alternatives select the common features that are found both in animal and plant cells.
  1. A. Cell membrane, nucleus, cytoplasm, lysosome and Golgi apparatus
  2. B. Cell membrane, nucleus, cytoplasm, mitochondria and endoplasmic reticulum
  3. C. Cell membrane, nucleus, cytoplasm, chloroplast and Golgi apparatus
  4. D. Cell membrane, nucleus, cytoplasm, large vacuole and Golgi apparatus
Worked solutionUnofficial

Answer: B

Answer B: Cell membrane, nucleus, cytoplasm, mitochondria and endoplasmic reticulum. The stem is: From the following alternatives select the common features that are found both in animal and plant cells. Letter B is the Abrari key for this Cell biology.

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C. · natural · Q24 · Enzymes

Which one of the following statements is correct about the catalytic activities of enzymes? They
  1. A. change the overall nature of the products.
  2. B. allow reactions in cells to take place quickly.
  3. C. alter themselves at the end of biochemical reactions.
  4. D. increase the energy required to start a reaction.
Worked solutionUnofficial

Answer: B

Answer B: allow reactions in cells to take place quickly.. The stem is: Which one of the following statements is correct about the catalytic activities of enzymes? They Letter B is the Abrari key for this Enzymes.

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C. · natural · Q25 · Protein structure

Four students draw four different big protein structure posters. The contents of each of their structure are displayed in the following table. Student I: Polypeptide folded into α-helix and β-sheet, and hydrogen bond; Student II: Amino acid sequences and peptide bonds; Student III: Multiple folded protein subunits in a multi-subunit complex and haem group; Student IV: Side chain interaction of amino acids and overall 3-D shape. Based on the above information, which student drew secondary and quaternary structures, respectively?
  1. A. I and IV
  2. B. II and III
  3. C. I and III
  4. D. II and IV
Worked solutionUnofficial

Answer: C

Answer C: I and III. The stem is: Four students draw four different big protein structure posters. The contents of each of their structure are displayed in the following table. Student I: Polypeptide folded into α-helix and β-sheet, and hydrogen bond; Student II: Amino acid sequences and peptide bonds; Student I… Letter C is the Abrari key for this Protein structure.

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C. · natural · Q26 · Enzyme specificity

How does the induced-fit model explain enzyme specificity? They
  1. A. change the shape of active site slightly to fit substrates precisely.
  2. B. have a rigid active site that can just bind to single substrate.
  3. C. have multiple active sites that can fit to different substrates.
  4. D. bind to whatever the shape of substrate that fits to allosteric site.
Worked solutionUnofficial

Answer: A

Answer A: change the shape of active site slightly to fit substrates precisely.. The stem is: How does the induced-fit model explain enzyme specificity? They Letter A is the Abrari key for this Enzyme specificity.

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C. · natural · Q27 · Enzyme inhibition

What happens to the substrate molecule when competitive inhibitor binds with an enzyme? It
  1. A. undergoes conformational change.
  2. B. cannot bind with the active site.
  3. C. binds to the allosteric site temporarily.
  4. D. easily binds with the active site.
Worked solutionUnofficial

Answer: B

Answer B: cannot bind with the active site.. The stem is: What happens to the substrate molecule when competitive inhibitor binds with an enzyme? It Letter B is the Abrari key for this Enzyme inhibition.

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C. · natural · Q28 · Allosteric enzymes

What will happen to the reaction if you add a certain inhibitor or activator to the substrate having allosteric enzyme set up?
  1. A. Inhibitor binds to active site to speed up the reaction.
  2. B. Inhibitor binds to regulatory site to increase rate of reaction.
  3. C. Activator binds to active site to initiate the reaction.
  4. D. Activator binds to regulatory site to activate the reaction.
Worked solutionUnofficial

Answer: D

Answer D: Activator binds to regulatory site to activate the reaction.. The stem is: What will happen to the reaction if you add a certain inhibitor or activator to the substrate having allosteric enzyme set up? Letter D is the Abrari key for this Allosteric enzymes.

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C. · natural · Q29 · Enzyme classification

Which one of the following classes of enzyme and type of reactions they catalyze is correctly matched?
  1. A. Oxidoreductases - transfer functional groups from donor to acceptor
  2. B. Transferases - transfer of electrons from one molecule to another
  3. C. Ligases - cleave bonds by other means rather than hydrolysis
  4. D. Lyases - catalyze the hydrolysis of various bonds
Worked solutionUnofficial

Answer: C

Answer C: Ligases - cleave bonds by other means rather than hydrolysis. The stem is: Which one of the following classes of enzyme and type of reactions they catalyze is correctly matched? Letter C is the Abrari key for this Enzyme classification. All four matches are imperfect; A/B/D swap definitions. C's description actually fits Lyases (ligases JOIN molecules using ATP), so the item is flawed. Site marks C as best-of-worst; a commenter flags answer as none. Kept C but flagged.

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C. · natural · Q30 · Enzyme kinetics / optimization

If a given enzyme works only at temperature range of 20 and 45 °C and the potential of hydrogen ions that ranges from 4 to 9. Which one of the following works best during the optimization of these two factors for the enzyme activity?
  1. A. Adjusting the temperature below 20°C makes the enzyme more active, hence the temperature at this value is optimal.
  2. B. Adjusting the pH above 9 can increase the probability of collisions between the enzyme and the substrate.
  3. C. Adjusting the temperature between 20°C and 45°C results little denaturation and increased number of collisions.
  4. D. The optimum pH under which this enzyme is most active is found below 4.
Worked solutionUnofficial

Answer: C

Answer C: Adjusting the temperature between 20°C and 45°C results little denaturation and increased number of collisions.. The stem is: If a given enzyme works only at temperature range of 20 and 45 °C and the potential of hydrogen ions that ranges from 4 to 9. Which one of the following works best during the optimization of these two factors for the enzyme activity? Letter C is the Abrari key for this Enzyme kinetics / optimization.

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C. · natural · Q64 · Chloroplast structure

What are the roles of grana and stroma in the process of photosynthesis? Grana is a site for
  1. A. cyclic pathway while stroma is a site for non-cyclic pathway.
  2. B. photolysis of water while stroma is a site for carbon fixation.
  3. C. generation of sugar while stroma is a site for photolysis of water.
  4. D. production of NADPH while stroma is a site for chemiosmosis.
Worked solutionUnofficial

Answer: B

Answer B: photolysis of water while stroma is a site for carbon fixation.. The stem is: What are the roles of grana and stroma in the process of photosynthesis? Grana is a site for Letter B is the Abrari key for this Chloroplast structure.

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C. · natural · Q67 · Photorespiration

What happens in the mitochondrion during the reactions of photorespiration?
  1. A. Glycine is converted to serine with the release of CO2 and NH3.
  2. B. Glycolate is converted to glyoxylate with the release of H2O2.
  3. C. Glycerate is converted to GP with the release of ADP.
  4. D. Phosphoglycolate is converted to glycolate with the release of Pi
Worked solutionUnofficial

Answer: A

Answer A: Glycine is converted to serine with the release of CO2 and NH3.. The stem is: What happens in the mitochondrion during the reactions of photorespiration? Letter A is the Abrari key for this Photorespiration.

Unofficial — solved by Abrari, not an official EAES key.

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2017 E.C. · natural · Q69 · Cellular respiration / phosphorylation

Which of the following is the difference between substrate level phosphorylation and oxidative phosphorylation? Substrate level phosphorylation
  1. A. occurs in the inner mitochondrial membrane while oxidative phosphorylation occurs in the cytosol.
  2. B. occurs during glycolysis and Kreb's cycle while oxidative phosphorylation occurs during electron transport chain.
  3. C. has the same source of energy as oxidative phosphorylation.
  4. D. occurs in aerobic respiration while oxidative phosphorylation in anaerobic respiration.
Worked solutionUnofficial

Answer: B

Answer B: occurs during glycolysis and Kreb's cycle while oxidative phosphorylation occurs during electron transport chain.. The stem is: Which of the following is the difference between substrate level phosphorylation and oxidative phosphorylation? Substrate level phosphorylation Letter B is the Abrari key for this Cellular respiration / phosphorylation.

Unofficial — solved by Abrari, not an official EAES key.

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