biol 373- unit 7
what is metabolism - correct answer ✔✔"set of life-sustaining chemical transformations within the cells
of living organisms"
whether transformations of energy substrates (carbs, fats, proteins) are biased toward
storage/ anabolism or breakdown/ catabolism
how is metabolism regulated - correct answer ✔✔• endocrine - primary role- products of endocrine
pancreas• insulin/glucagon ratio
• neural - regulation of food intake- endocrine pancreas also innervated (autonomic)
ingested biomolecules have what three fates - correct answer ✔✔fuel - metabolized to provide energy
build - synthesis reactions for growth and maintenance of tissues
store - as glycogen (liver, skeletal muscles) or fat
metabolism is divided into what two states - correct answer ✔✔fed / absorptive state - anabolic,
products of digestion being absorbedand used for synthesis or stored; building phase
fasted / postabsorptive state - catabolic, body taps into stores; keeping up glucose or using alternate fuel
nutrient pools for immediate use - correct answer ✔✔mostly circulating in plasma):
• glucose
• free fatty acids
• amino acids
what do enzymes do in fed-state metabolism - correct answer ✔✔In fed-state metabolism under
influence of insulin, enzymeactivity for forward reaction increases.Enzymes for glycogen breakdown are
inhibited
net glycogen synthesis
, favouring the glucose to glycogen pathway
what do enzymes do in fasted-state metabolism - correct answer ✔✔In fasted-state metabolism under
influence of glucagon et al,enzymes that break down glycogen are more active, and enzymesfor glycogen
synthesis are inhibited.
net glucose synthesis
favouring breakdown of glycogen
interconversions of carbohydrate, fat and protein - correct answer ✔✔slide 5 unit 7
always running these cycles to keep ourselves alive
fasted state we are breaking down glycogen and glycerol into the gluconeogenesis pathway and burn
fatty acids to use as fuel and maek acetylcoA
what are three characteristics of fasted (postabsorptive) state metabolism - correct answer ✔✔• under
the control of hormones
• goal is to maintain plasma glucose levels- achieved through pathways that yield glucose or provide ATP
via alternate fuels
• brain is acutely dependent on glucose(can also use ketones)
carbs storage centres for fasted state - correct answer ✔✔liver and muscle
how is glucose stored in liver - correct answer ✔✔glycogen in liver - can be broken down and exported
as free glucose
how is glucose stored and exported in muscle - correct answer ✔✔glycogen in muscle - can NOT be
exported as free glucose- use within muscle, OR- export as pyruvate or lactate liver gluconeogenesis-
glycogen is main source of glucose for fasted state» liver keeps ~4 h supply of glycogen
fats are stored in - correct answer ✔✔liver and adipose tissue?
what is metabolism - correct answer ✔✔"set of life-sustaining chemical transformations within the cells
of living organisms"
whether transformations of energy substrates (carbs, fats, proteins) are biased toward
storage/ anabolism or breakdown/ catabolism
how is metabolism regulated - correct answer ✔✔• endocrine - primary role- products of endocrine
pancreas• insulin/glucagon ratio
• neural - regulation of food intake- endocrine pancreas also innervated (autonomic)
ingested biomolecules have what three fates - correct answer ✔✔fuel - metabolized to provide energy
build - synthesis reactions for growth and maintenance of tissues
store - as glycogen (liver, skeletal muscles) or fat
metabolism is divided into what two states - correct answer ✔✔fed / absorptive state - anabolic,
products of digestion being absorbedand used for synthesis or stored; building phase
fasted / postabsorptive state - catabolic, body taps into stores; keeping up glucose or using alternate fuel
nutrient pools for immediate use - correct answer ✔✔mostly circulating in plasma):
• glucose
• free fatty acids
• amino acids
what do enzymes do in fed-state metabolism - correct answer ✔✔In fed-state metabolism under
influence of insulin, enzymeactivity for forward reaction increases.Enzymes for glycogen breakdown are
inhibited
net glycogen synthesis
, favouring the glucose to glycogen pathway
what do enzymes do in fasted-state metabolism - correct answer ✔✔In fasted-state metabolism under
influence of glucagon et al,enzymes that break down glycogen are more active, and enzymesfor glycogen
synthesis are inhibited.
net glucose synthesis
favouring breakdown of glycogen
interconversions of carbohydrate, fat and protein - correct answer ✔✔slide 5 unit 7
always running these cycles to keep ourselves alive
fasted state we are breaking down glycogen and glycerol into the gluconeogenesis pathway and burn
fatty acids to use as fuel and maek acetylcoA
what are three characteristics of fasted (postabsorptive) state metabolism - correct answer ✔✔• under
the control of hormones
• goal is to maintain plasma glucose levels- achieved through pathways that yield glucose or provide ATP
via alternate fuels
• brain is acutely dependent on glucose(can also use ketones)
carbs storage centres for fasted state - correct answer ✔✔liver and muscle
how is glucose stored in liver - correct answer ✔✔glycogen in liver - can be broken down and exported
as free glucose
how is glucose stored and exported in muscle - correct answer ✔✔glycogen in muscle - can NOT be
exported as free glucose- use within muscle, OR- export as pyruvate or lactate liver gluconeogenesis-
glycogen is main source of glucose for fasted state» liver keeps ~4 h supply of glycogen
fats are stored in - correct answer ✔✔liver and adipose tissue?
