Copiar e Editar

Biochemistry MCQs- MAY 12

Descrição

Quiz sobre Biochemistry MCQs- MAY 12, criado por MatthewEllis96 em 02-02-2015.
MatthewEllis96
Quiz por MatthewEllis96, atualizado more than 1 year ago
MatthewEllis96
Criado por MatthewEllis96 quase 10 anos atrás
49
0
0

Resumo de Recurso

Questão 1

Questão
The glycolytic pathway in dinosaurs
Responda
  • Was likely to be completely different to modern day animals, because every organism has different metabolic pathways
  • Was likely to be completely different to modern day organisms because they eat different types of food
  • Was likely to be similar or identical to modern day organisms, because metabolic pathways have been highly conserved through evolution
  • Is something we cannot make meaningful predictions about because we have no knowledge of how metabolism has evolved

Questão 2

Questão
In thin layer chromatography, ninhydrin can be used to stain which compounds?
Responda
  • Monosaccharides
  • Amino acids
  • Keto acids
  • All of the above

Questão 3

Questão
Which of the following lists contains the components of a phospholipid?
Responda
  • Choline, phosphate group, glycerol, fatty acids
  • Choline, phosphate group, glyceraldehyde, fatty acids
  • Carnitine, phosphate group, glycerol, amino acids
  • Carnitine, phosphate group, glyceraldehyde, amino acids

Questão 4

Questão
Testosterone belongs to which class of compounds?
Responda
  • Fats
  • Oils
  • Ketose monosaccharides
  • Sterols

Questão 5

Questão
Which of the following passes easily through phospholipid bilayers?
Responda
  • Chloride ions
  • ATP
  • Glucose 6-phosphate
  • Water

Questão 6

Questão
Peripheral membrane proteins
Responda
  • Pass through the cell membrane
  • Are non-covalently associated with integral membrane proteins
  • Are covalently linked to membrane lipids
  • Are always linked to sugars

Questão 7

Questão
Which of the following fatty acids is likely to have the highest melting temperature?
Responda
  • One with 14 carbon atoms and no double bonds
  • One with 14 carbon atoms and one double bond
  • One with 16 carbon atoms and no double bonds
  • One with 16 carbon atoms and one double bond

Questão 8

Questão
In the furanose ring form of β-D-fructose, how many of the carbon atoms are chiral?
Responda
  • 0
  • 2
  • 4
  • 6

Questão 9

Questão
Cellulose is a polymer of
Responda
  • α-D-glucose units only
  • β-D-glucose units only
  • α-D-glucose and β-D-fructose units
  • β-D-glucose and α-D-fructose units

Questão 10

Questão
In catabolic (degradative) reactions in humans, the most commonly used oxidising cofactors are
Responda
  • NAD+ and FAD
  • NADP+ and FAD
  • NADH and FADH2
  • NADPH and FADH2

Questão 11

Questão
Considering only the glycolytic pathway, what is the net gain in ATP molecules, per molecule of glucose processed?
Responda
  • 0
  • 1
  • 2
  • 4

Questão 12

Questão
Under anaerobic conditions, glycolysis in mammals can result in the compound lactose. Why?
Responda
  • To make ATP by substrate level phosphorylation
  • To regenerate NAD+
  • To make NADH for oxidative phosphorylation
  • To replenish Krebs’ (tricarboxylic acid) cycle intermediates

Questão 13

Questão
Which of the following statements about gluconeogenesis is TRUE?
Responda
  • Glucose is generated from the hydrolysis of phosphate from glucose 6-phosphate. No ATP is produced in this reaction.
  • Glucose is generated from the hydrolysis of phosphate from glucose 6-phosphate. One molecule of ATP is produced in this reaction.
  • In mammals, acetyl coenzyme A (AcCoA) can be a starting point.
  • The reactions are exactly the same as glycolysis, except in reverse.

Questão 14

Questão
Isomerisation of glucose 1-phosphate to glucose 6-phosphate occurs in
Responda
  • Glycolysis and gluconeogenesis
  • Glycogen synthesis and degradation
  • Glycolysis and the Leloir pathway
  • The Leloir pathway and glycogen degradation

Questão 15

Questão
In the Calvin cycle, carbon dioxide reacts with ribulose 1,5-bisphosphate. The first product(s) of this reaction is/are:
Responda
  • Two molecules of 3-phosphoglycerate
  • Two molecules of glyceraldehyde 3-phosphate
  • One molecule of glucose 6-phosphate
  • One molecule of fructose 6-phosphate

Questão 16

Questão
In Calvin’s experiments to identify the compounds in the Calvin cycle, the function of the hot ethanol was
Responda
  • To shield the algae from the heat of the lamps
  • To provide a source of carbon atoms for the algae
  • To kill the algae after a defined time point
  • To solublise the compounds in the algae

Questão 17

Questão
The main source of energy for sperm cells is
Responda
  • Glucose
  • Fatty acids
  • Glycerol
  • Fructose

Questão 18

Questão
The transition state in an enzyme-catalysed reaction:
Responda
  • Is always covalently associated to the enzyme.
  • Is never covalently associated to the enzyme.
  • Can never be observed experimentally.
  • Can often be similar in structure to potent enzyme inhibitors.

Questão 19

Questão
In enzyme catalysis, the term ‘approximation’ refers to:
Responda
  • A catalytic strategy that facilitates transition state stabilisation through formation of covalent bonds between a substrate and amino acid groups in the active site.
  • A catalytic strategy that facilitates transition state stabilisation through formation of hydrogen bonds and electrostatic interactions between a substrate and amino acid groups in the active site.
  • A catalytic strategy that facilitates transition state stabilisation through interaction with metal ions in the active site.
  • A catalytic strategy that facilitates transition state stabilisation through direct transfer of a proton to the substrate from an acidic amino acid group in the active site.

Questão 20

Questão
The Urea cycle:
Responda
  • Is completely located in the mitochondrial matrix – preventing the exposure of free ammonium to other components of the eukaryote cell.
  • Allows free ammonia obtained directly from de-amination of glutamate to be converted to urea – preventing the exposure of free ammonium to other components of the eukaryote cell.
  • Allows free ammonia obtained directly from de-amination of tryptophan to be converted to urea – preventing the exposure of free ammonium to other components of the eukaryote cell.
  • Is completely located in the cytoplasm of the cell – preventing the exposure of free ammonium to other components of the eukaryote cell.

Questão 21

Questão
Serine proteases:
Responda
  • Are proteases that hydrolyse polypeptides with serine in the F1 position
  • Are proteases that are found in the cytoplasm of all cells
  • Utilise a serine residue at the active site to facilitate substrate binding
  • Utilise a serine residue at the active site to facilitate cleavage of peptide bonds

Questão 22

Questão
Consider an enzyme that shows Michaelis-Menton kinetics where: vo = Vmax . [S] / (Km + [S]) If a substrate, S, is present at a concentration of 4 mM, and Km is 2 mM, the rate of reaction (vo) measured will be:
Responda
  • Half of Vmax
  • Two thirds of Vmax
  • Double Vmax
  • Three times Vmax

Questão 23

Questão
In acid-base catalysis:
Responda
  • An acidic- or basic- amino acid in the active site of an enzyme facilitates transition state formation by hydrogen abstraction from an appropriate substrate.
  • An acid- or basic- substrate in the active site of an enzyme facilitates transition state formation by hydrogen abstraction from a catalytic amino acid in the active site.
  • Both are correct.
  • Neither are correct.

Questão 24

Questão
The protein ubiquitin:
Responda
  • Can be covalently linked to proteins via the N-terminus glycine residue.
  • Is a polypeptide.
  • Is an essential component of eukaryote respiratory chains.
  • Can be covalently linked to proteins via isopeptide bond formation.

Questão 25

Questão
An oxyanion hole is:
Responda
  • A region of the enzyme active site that facilitates binding of positively charged substrates through their association with oxygen-containing amino-acid side chains in the enzyme.
  • A region of the enzyme active site that facilitates binding of negatively charged substrates through their association with oxygen-containing amino acid side chains in the enzyme.
  • A region of the active site that facilitates binding of positively charged oxygen containing groups present in a substrate.
  • A region of the active site that facilitates binding of negatively charged oxygen-containing groups present in a substrate.

Questão 26

Questão
If the ΔG°′ of the reaction Malate → Oxaloacetate is +30 kJ/mol, what will happen in the presence of malate dehydrogenase under standard conditions?
Responda
  • The reaction will proceed fast with the formation of the explosive products.
  • The reaction will not occur spontaneously.
  • The reaction will never reach equilibrium.
  • The reaction will proceed spontaneously from left to right.

Questão 27

Questão
Which of the following redox couple have the highest midpoint redox potential?
Responda
  • ubiquinol/ubiquinone
  • NADH/NAD+
  • H2O/½O2
  • ferrocytochrome c/ferricytochrome c

Questão 28

Questão
What is the source of energy for ATP synthesis in mitochondria?
Responda
  • AMP, ADP and inorganic phosphate
  • Gradient of Na+ across the inner mitochondrial membrane
  • Matrix fumarase and aconitase
  • None of the above

Questão 29

Questão
Which of the following cannot reduce mitochondrial respiratory chain in normal conditions?
Responda
  • NADH
  • Oxygen
  • FADH2
  • Ubiquinol

Questão 30

Questão
The oxygen molecules released into the air as a product of photosynthesis comes from:
Responda
  • Light quanta
  • Cytochome c oxidase
  • Carbon dioxide
  • Water

Questão 31

Questão
Production of lactic acid in anaerobic muscle cells is:
Responda
  • Caused by breakdown of glycogen
  • Caused by a buildup of AMP
  • Coupled to the recycling of NAD+ to NADH by lactate dehydrogenase when it oxidises pyruvate
  • Due to pyruvate being reduced by lactate dehydrogenase while it recycles NADH to NAD+

Questão 32

Questão
Phosphofructokinase-1 activity is:
Responda
  • Inhibited by fructose 2,6-bisphosphate
  • Inhibited by AMP
  • Inhibited by citrate
  • Stimulated by citrate

Questão 33

Questão
The Warburg effect:
Responda
  • Is the inhibition of glycolysis that occurs in anaerobic cells when exposed to oxygen
  • Is the continued use of anaerobic fermentation by cancer cells even in the presence of oxygen
  • Is caused by an over-active glycerol phosphate shuttle in cancer
  • Is due to the inhibition of phosphofructokinase-1 by AMP

Questão 34

Questão
Glycogen synthase activity is:
Responda
  • Inhibited by ATP
  • Stimulated by glucose 6-phosphate
  • Stimulated by fructose 1,6-bisphosphate
  • Inhibited by citrate

Questão 35

Questão
Phosphofructokinase-1 activity is:
Responda
  • Stimulated by citrate
  • Inhibited by AMP
  • Inhibited by citrate
  • Inhibited by fructose 2,6-bisphosphate

Questão 36

Questão
Which of the following is NOT true of Aldosterone?
Responda
  • It is a mineralocorticoid
  • It is a peptide hormone
  • It is a steroid hormone
  • It is released in response to angiotensin II

Questão 37

Questão
Calcitonin is a hormone that is released from:
Responda
  • The pituitary gland
  • The thyroid gland
  • The hypothalamus
  • The parathyroid gland

Questão 38

Questão
Which of the following is NOT a feature of metabolic pathways?
Responda
  • Sequential feedback inhibition
  • Common intermediate metabolites
  • The presence of aquaporins
  • End product inhibition

Questão 39

Questão
Which of the following is NOT true of the anabolic hormone insulin?
Responda
  • It increases glycogen synthesis
  • It increases fatty acid synthesis
  • It increases esterification of fatty acids
  • It increases protein breakdown (proteinolysis)

Questão 40

Questão
Which of the following has NOT been a commercial method for the synthesis of artificial human insulin?
Responda
  • Separate A- and B-chain synthesis in E. coli
  • Phage display in E. coli
  • Pro-insulin synthesis in E. coli
  • Biosynthesis in brewer’s yeast (Saccharomyces cerevisiae)

Quer criar seus próprios Quizzes gratuitos com a GoConqr? Saiba mais.

Semelhante

Tipos de Trabalhos Científicos
Rebeca Sales
Matérias para Estudar para o Vestibular
Alice Sousa
Função Polinomial do 1º Grau
KauanM
Histologia Humana - Tecido Epitelial
Marcella F. Brunhara
Mapa Conceitual
Eduardo Morais
TÉCNICAS DE ESTUDO
Rafael Fernando
História da Arte
GoConqr suporte .
Estrutura e Formação de Palavras
adrianegonaves
Sistema Circulátorio
Daniela Barreto3004
Direito Constitucional focado (INSS 2016) - Direitos e Garantias Fundamentais e Administração Pública
Thiago Amério
Sócrates, Platão e Aristóteles
André Matias
Explore a Biblioteca