1949681
Descripción
Test por MatthewEllis96, actualizado hace más de 1 año
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Creado por MatthewEllis96
hace más de 9 años
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Pregunta 1
Pregunta
IF WE WERE ABLE TO DETERMINE THE REACTIONS OF THE KREBS’ (TRICARBOXYLIC ACID) CYCLE FROM A WOOLLY MAMMOTH, WOULD YOU EXPECT THEM TO BE:
Respuesta
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Totally different from the ones found in humans, but similar to those in elephants
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Essentially the same as the ones found in both humans and elephants
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Totally different to the ones found in humans and elephants
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Similar to those in other extinct mammals, but very different from anything alive today
Pregunta 2
Pregunta
AN END-PRODUCT CAN ACT TO INHIBIT AN ENZYME BY BINDING AT THE:
Respuesta
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Transitional site
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Active site
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Activation site
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Allosteric site
Pregunta 3
Pregunta
THE SINGLE BIGGEST SIDE-EFFECT OF INSULIN THERAPY IS:
Respuesta
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A fear of needles
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Hyperactivity
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Hypoglycaemia
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Hyperglycaemia
Pregunta 4
Pregunta
WHICH OF THE FOLLOWING IS A COMMON PHYSIOLOGICAL METHOD OF LOWERING BODY TEMPERATURE?
Respuesta
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Stimulation of the mitochondria in brown fat cells
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Rhythmic Stimulation of skeletal muscle
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Increased thyroid gland activity
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Accelerated respiration
Pregunta 5
Pregunta
WHICH OF THE FOLLOWING STATEMENTS CONCERNING ENZYME CASCADES IS FALSE?
Respuesta
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They amplify and diversify signals of hormones such as cyclic AMP
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They are usually found in the extracellular space
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They often involve second messengers
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Multiple enzymes undergo conformational change and become activated
Pregunta 6
Pregunta
WHICH OF THE FOLLOWING STATEMENTS CONCERNING STEROID HORMONES IS TRUE?
Respuesta
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They bind to cytoplasmic and/or nuclear proteins to form a hormone receptor complex
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They are transcription factors
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They bind and activate membrane-bound receptors
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They are hydrophilic compounds
Pregunta 7
Pregunta
THE ENZYME-SUBSTRATE COMPLEX:
Respuesta
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Is a key concept that helps to explain how enzymes reduce activation energy for chemical reactions.
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Is a key concept that helps to explain how enzymes can reduce the Gibb’s free energy for a chemical reaction.
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Is a key concept that helps to explain how enzymes can exhibit diverse substrate specificity.
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Is a key concept that helps to explain how enzymes may exhibit Michaelis-Menton kinetics.
Pregunta 8
Pregunta
CONSIDER AN ENZYME THAT SHOWS MICHAELIS-MENTON ENZYME KINETICS, WHERE:
Vo = Vmax . [S] / Km + [S]
If a substrate, S, is present at a concentration of 6 mM, and Km is 2 mM, the rate of reaction (Vo) measured will be:
Respuesta
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One third of Vmax
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Three times Vmax
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Three quarters of Vmax
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Six times Vmax
Pregunta 9
Pregunta
AN OXYANION HOLE IS:
Respuesta
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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.
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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.
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A region of the active site that facilitates binding of positively charged oxygen-containing groups present in a substrate.
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A region of the active site that facilitates binding of negatively charged oxygen-containing groups present in a substrate.
Pregunta 10
Pregunta
THE ENTHALPY CHANGE ASSOCIATED WITH A BIOCHEMICAL REACTION:
Respuesta
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Is a term used to describe the amount of randomness or disorder that results as the reaction proceeds
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Is a term used to describe the amount of ‘free energy’ change that results as the reaction proceeds
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Is a term used to describe the amount of heat that is produced or consumed as the reaction proceeds
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Is always determined at room temperature (25oC)
Pregunta 11
Pregunta
ENZYMES USUALLY UTILISE ONE OR MORE TRANSITION METAL ATOMS AT THE ACTIVE SITE TO:
Respuesta
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Facilitate substrate binding
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Facilitate transition state formation
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Facilitate stabilisation of the tertiary structure
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Facilitate conformational changes in the protein during the catalytic cycle
Pregunta 12
Pregunta
ENZYMES:
Respuesta
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Reduce the entropy associated with chemical reactions
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Reduce the enthalpy associated with chemical reactions
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Reduce the Gibb’s free energy associated with chemical reactions
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Reduce the activation energy associated with chemical reactions
Pregunta 13
Pregunta
THE TRANSITION STATE IN AN ENZYME-CATALYSED REACTION:
Respuesta
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Is always covalently associated to the enzyme.
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Is never covalently associated to the enzyme.
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Can never be observed experimentally.
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Can often be similar in structure to potent enzyme inhibitors.
Pregunta 14
Pregunta
SERINE PROTEASES:
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Are proteases that hydrolyse polypeptides with serine in the F1 position
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Are proteases that are found in the cytoplasm of all cells
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Utilise a serine residue at the active site to facilitate substrate binding
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Utilise a serine residue at the active site to facilitate cleavage of peptide bonds
Pregunta 15
Pregunta
THE UBIQUITIN PROTEIN:
Respuesta
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Is only found in eukaryotic cells
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Is only found in bacterial cells
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Is a key component of the Urea cycle
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Is a key component of the Ubiquitin cycle
Pregunta 16
Pregunta
THE ALANINE CYCLE:
Respuesta
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Is completely located in the mitochondrial matrix.
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Facilitates transport of ammonia produced in the liver to the muscles where it can be used in anabolic processes - preventing the exposure of free ammonium to other components of eukaryote tissues.
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Facilitates transport of ammonia produced in the muscles to the liver where it can be effectively removed from the body - preventing the exposure of free ammonium to other components of eukaryote tissues.
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Is completely located in the cytoplasm of the cell – preventing the exposure of free ammonium to other components of eukaryote tissues.
Pregunta 17
Pregunta
THE MOST COMMON FORM OF FRUCTOSE IN SOLUTION IS:
Respuesta
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A pyranose (six-membered) ring form
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A furanose (five-membered) ring form
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A straight chain, ketone form
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A straight chain, aldehyde form
Pregunta 18
Pregunta
FATTY ACIDS:
Respuesta
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Have a hydrophobic aliphatic carbon chain and a hydrophilic carboxylic acid group
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Have a hydrophilic aliphatic carbon chain and a hydrophobic carboxylic acid group
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Have a hydrophobic aliphatic carbon chain and a hydrophobic carboxylic acid group
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Have a hydrophilic aliphatic carbon chain and a hydrophilic carboxylic acid group
Pregunta 19
Pregunta
TESTOSTERONE IS:
Respuesta
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A sterol
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A ketose monosaccharide
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A fatty acid
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A cofactor
Pregunta 20
Pregunta
WHICH IF THESE MOLECULES IS COMMONLY INVOLVED IN CELL SIGNALLING AND RIBOSOMAL TRANSLOCATION?
Respuesta
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TTP
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CTP
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UTP
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GTP
Pregunta 21
Pregunta
THE PRECURSORS FOR THE BIOSYNTHESIS OF SUCROSE ARE:
Respuesta
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UDP-glucose and fructose 6-phosphate
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UDP-fructose and glucose 6-phosphate
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UDP-glucose and fructose
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UDP-fructose and glucose
Pregunta 22
Pregunta
TO DETERMINE THE IDENTITIES OF THE COMPOUNDS IN THE CALVIN CYCLE, MELVIN CALVIN USED:
Respuesta
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Nuclear magnetic resonance spectroscopy and chemical analysis
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Paper chromatography and mass spectrometry
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Paper chromatography and chemical analysis
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Chemical analysis and mass spectrometry
Pregunta 23
Pregunta
TRIOSE PHOSPHATE ISOMERASE CATALYSES THE ATTAINMENT OF EQUILIBRIUM BETWEEN THE GLYCOLYTIC INTERMEDIATES GLYCERALDEHYDE 3-PHOSPHATE AND DIHYDROXYACETONE PHOSPHATE. UNDER THE CONDITIONS PREVAILING IN A HUMAN CELL, ON WHICH SIDE DOES THE EQUILIBRIUM LIE?
Respuesta
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It is not possible to know this from the information provided
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Dihydroxyacetone phosphate
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The equilibrium is approximately equally balanced
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Glyceraldehyde 3-phosphate
Pregunta 24
Pregunta
CONSIDER TWO REACTIONS. REACTION 1 HAS A ΔG°′ VALUE OF -20 kJ.mol-1 AND REACTION 2 HAS A ΔG°′ VALUE OF -50 kJ.mol-1. WHICH REACTION PROCEEDS AT THE FASTEST RATE AT ROOM TEMPERATURE AND PRESSURE AND pH 7?
Respuesta
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Reaction 1
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Reaction 2
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They both occur at much the same rate
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It is not possible to know this from the data provided
Pregunta 25
Pregunta
IN GLYCOLYSIS, THE CONVERSION OF PHOSPHOENOLPYRUVATE TO PYRUVATE IS COUPLED TO:
Respuesta
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The phosphorylation of ADP to make ATP
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The phosphorylation of GDP to make GTP
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The reduction of NAD+ to make NADH
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The oxidation of NADPH to make NADP+
Pregunta 26
Pregunta
IN YEAST UNDER ANAEROBIC CONDITIONS, ETHANOL IS PRODUCED AT THE END OF THE GLYCOLYTIC PATHWAY. WHY IS THIS ADVANTAGEOUS TO THE YEAST?
Respuesta
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It enables the regeneration of NAD+
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It enables it to produce more NADH
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A molecule of ATP can be produced from the reaction
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It helps the brewing industry
Pregunta 27
Pregunta
UNDER ANAEROBIC CONDITIONS IN HUMANS, HOW MANY MOLECULES OF CARBON DIOXIDE (CO2) ARE PRODUCED BY THE METABOLISM OF ONE MOLECULE OF GLUCOSE BY GLYCOLYSIS AND SUBSEQUENT PATHWAYS?
Respuesta
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6
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4
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2
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0
Pregunta 28
Pregunta
LACTOSE IS A DISACCHARIDE OF:
Respuesta
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Glucose and mannose
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Mannose and fructose
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Galactose and fructose
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Glucose and galactose
Pregunta 29
Pregunta
THE COFACTOR FAD (FLAVIN ADENINE DINUCLEOTIDE) IS COMPOSED OF WHICH SUBUNITS?
Respuesta
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Flavin, ribose, adenine and three phosphates
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Flavin, two riboses, two adenines and a phosphate
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Flavin, two riboses, two adenines and two phosphates
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Flavin, ribose, adenine and two phosphates
Pregunta 30
Pregunta
NADPH IS USED IN THE CALVIN CYCLE TO:
Respuesta
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Oxidise 1,3-bisphosphoglycerate
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Reduce 1,3-bisphosphoglycerate
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Oxidise ribulose 1,5-bisphosphate
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Reduce ribulose 1,5-bisphosphate
Pregunta 31
Pregunta
IN GLUCONEOGENESIS, THE CORRECT SEQUENCE OF COMPOUNDS IN THE CONVERSION OF PYRUVATE TO PHOSPHOENOLPYRUVATE IS:
Respuesta
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Pyruvate → Oxaloacetate → Phosphoenolpyruvate
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Pyruvate → Lactate → Phosphoenolpyruvate
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Pyruvate → Succinate → Phosphoenolpyruvate
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Pyruvate → 1,3-bisphosphoglycerate → Phosphoenolpyruvate
Pregunta 32
Pregunta
THE INCREASE IN ATP LEVELS THAT ACCOMPANIES THE "PASTEUR EFFECT" CAUSES:
Respuesta
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decreased glycolytic flux by allosteric stimulation of lactate dehydrogenase
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allosteric inhibition of fructose 1,6-bisphosphatase
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allosteric inhibition of phosphofructokinase-1
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increased glycolytic flux by allosteric activation of phosphofructokinase-2
Pregunta 33
Pregunta
GLYCOGEN PHOSPHORYLASE IS:
Respuesta
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inhibited by phosphorylation
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activated by phosphorylation
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activated by glucose
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inhibited by AMP
Pregunta 34
Pregunta
PROTEIN KINASE A:
Respuesta
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is an allosteric enzyme
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phosphorylates phosphorylase kinase
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phosphorylates glycogen phosphorylase
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is activated by ADP
Pregunta 35
Pregunta
ADRENALINE:
Respuesta
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induces glycogen synthesis in the liver
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induces gluconeogenesis in the liver
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accelerates glyconeogenesis in the heart
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inhibits glycolysis in the heart
Pregunta 36
Pregunta
GLYCOGEN PHOSPHORYLASE KINASE
Respuesta
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is activated by cAMP
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is activated by dephosphorylation
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is activated by autophosphorylation
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is activated by protein kinase A
Pregunta 37
Pregunta
WHAT IS THE SOURCE OF ENERGY FOR ATP SYNTHESIS IN MITOCHONDRIA?
Respuesta
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ADP and inorganic phosphate
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Gradient of NADH across the inner mitochondrial membrane
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Matrix aconitase
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None of the above
Pregunta 38
Pregunta
WHAT IS THE OVERALL EQUATION FOR PHOTOSYNTHESIS?
Respuesta
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18 CO2+ 2 NADPH + 3 ATP + light → 2 NADPH + 3 Glucose-1-phosphate + 3 ADP + 18 O2
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2 H2O + 2 NADP+ + 3 ADP + 3 Pi + light → 2 NADPH + 2 H+ + 3 ATP + O2
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2 H2O + 2 NAD+ 2 Pi → 2 NADPH + 2 H+ + O2 + light
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CO2 + light + H2O → Glucose + O2
Pregunta 39
Pregunta
WHICH OF THE FOLLOWING IS NOT A REDOX CENTRE FOR RESPIRATORY CHAIN?
Respuesta
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NADH
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Cytochrome c
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Oxygen
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FADH2
Pregunta 40
Pregunta
THE OXYGEN MOLECULES RELEASED INTO THE AIR AS A PRODUCT OF PHOTOSYNTHESIS COMES FROM:
Respuesta
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Light quanta
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Cytochome c oxidase
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Water
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Carbon dioxide
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