Final Integration of metabolism Flashcards
The basic chemical strategy that governs the metabolism of living organisms are?
breakdown of fuel molecules to generate ATP,
reducing power,
building blocks for biosynthesis.
Brain metabolic profile
fuel reserves:
Preferred fuel:
Fuel source exported:
fuel reserves: none
Preferred fuel: glucose
Fuel source exported: none
Skeletal muscle resting metabolic profile
fuel reserves: glycogen+ protein
Preferred fuel: fatty acid
Fuel source exported: none
Skeletal muscle during exertion metabolic profile
fuel reserves:
Preferred fuel:
Fuel source exported:
fuel reserves: none
Preferred fuel: glucose
Fuel source exported: lactate
Heart metabolic profile
fuel reserves:
Preferred fuel:
Fuel source exported:
fuel reserves: none
Preferred fuel: fatty acids
Fuel source exported: none
Adipose tissue metabolic profile
fuel reserves: triacylglycerol
Preferred fuel: fatty acids
Fuel source exported: fatty acids glycerol
liver metabolic profile
fuel reserves:
Preferred fuel:
Fuel source exported:
fuel reserves: glycogen
Preferred fuel: glucose, fatty acids, amino acids
Fuel source exported: fatty acids, glucose, ketone bodies
The brain can store glucose and consumes less than 60% of the glucose used by a resting human each day. True or false?
false- The brain lacks defined fuel stores of its own and requires a continuous supply of glucose, consuming about 60% of the glucose used by a resting human each day
The brain in a low aerobic organ. T or F
false
During starvation, ketone bodies produced in the liver help brain tissue compensate for the lack of glucose in the blood. TorF
true
Fatty acids are not used by the brain for energy production T or F
true
During long periods of rest, the muscle prefers glucose. True or false
false- fatty acids are more preferred
in active muscle tissue, the rate of glycolysis far exceeds that of the TCA cycle T or F?
true
What is the liver’s role for when the muscle produces excess pyruvate?
pyruvate is converted into lactate then transported into the liver and converts it back to glucose
When are amino acids used for energy?
utilized for energy only during long-term exertion (even starvation)
How is alanine produced in muscle tissue related to liver?
during muscle protein breakdown, is also effectively transported to the liver and converted back into glucose
why is the liver function essential to muscle cells?
A functional liver is essential to muscle physiology because muscle cells lack a
the heart is highly aerobic meaning it will produce lactate. true or false?
False
The heart muscle requires a continuous supply of fuels true or false?
true
What is the major fuel reserve for an animal?
Adipose tissue
esterification of fatty acids to form triacylglycerols and for the release of free fatty acids are specialized for what organ?
Adipose tissue
How do adipose tissues receive dietary lipids?
In the form of Chylomicrons
How are newly synthesized lipids that come the liver packaged?
VLDL
The liver serves as the metabolic hub of the body and is function is essential to provide adequate fuel only for the brain T or F
False - provides fuel for brain, muscle, and other peripheral tissue
The fasting state the liver produce what type of bodies?
Ketone bodies
Can the liver consume ketone bodies?
No
The liver can take up all fuels true or false?
false cannot take up ketone bodies
what is the medium of transport of hormonal signals from one tissue to another?
Blood
the human circulatory system has developed so that the portal vein from digestive tract lastly encounters the liver tissue T or False
false- encounter first so the liver has first access to important metabolites
In animals, blood glucose levels must be maintained within narrow limits. Under normal conditions the brain meets its energy requirements by using glucose. In humans the normal level of glucose in the blood is 4.4 mM (~80 mg/100 ml). This level might rise to 6.6 mM after a meal. what is done to regulate these levels ?
The liver plays a central role in glucose homeostasis (a constant level of glucose in the blood) as well as hormones
what are the three major hormones that are used in regulation of fuel metabolism
- Insulin
- Glucagon
- Epinephrine (shorter-lived effects)
High blood glucose levels stimulate the release of what hormone and from where?
insulin
pancreas
Blood glucose levels drop
low blood glucose stimulates the release of glucagon to liver
describe the opposing roles of insulin and glucagon in metabolism
Insulin sends signal in the fed state meanwhile glucagon is in the starved state.
Insulin signals the fed state and promotes:
- Uptake of fuels into some cells
- Storage of fuel (lipids and glycogen)
- Biosynthesis of macromolecules (proteins and
nucleic acids)
The main target of glucagon is the?
liver -where it raises the levels of cAMP to activate glucose production
what is glucagons role in adipose tissue?
glucagon increases the mobilization of triacylglycerols to yield fatty acids and glycero
Unlike insulin or glucagon, epinephrine is produced by the adrenal medulla in response to
low blood glucose levels
are the effects of epinephrine short or long-lived?
short
epinephrine can “override” insulin for long periods of time true or false?
false only short periods
All organisms must balance the ingestion and absorption of fuel molecules with the metabolism and storage of these nutrients to meet long-term and immediate energy needs. Maintenance of this balance is called?
Energy homeostasis
how is AMPK activated ?
activated by a high AMP/ATP ratio (in other words low energy).
Once AMPK is activated it leads what production and inhibition of what
initiates signaling pathways that lead to ATP production and inhibit pathways that utilize ATP
mTor (mammalian Target of Rapamycin) is inactive under nutrient-rich conditions and active in nutrient-poor conditions
False- mTor (mammalian Target of Rapamycin) is active under nutrient-rich conditions and inactive in nutrient-poor conditions
describe proliferative metabolism
If nutrients are abundant then cells take up the fuels and metabolize them through glycolysis. Rapid also inefficient
When nutrients are scarce, cells adapt to a …….. metabolism. Unicellular organisms then rely primarily on oxidative metabolism
Starvation metabolism
proliferative metabolism are examples of
unicellular metabolism
in a multicellular organism if food is abundant and it decides to go through proliferative metabolism. what conditions are placed?
Growth hormone presence
in a multicellular organism if food is abundant it decides to go through quiescent metabolism. what conditions are placed?
no growth hormone signal
The brain receives information about
the quality and quantity of nutrients being consumed
the levels of fuel already present in the blood
the amounts of energy present in various storage reserves in the
body
There are four principal endocrine regulators of food intake what are they
Leptin and insulin inhibit food intake
Ghrelin and adiponectin promote food intake
Which hormones activate hypothalamic AMPK
activated by ghrelin and adiponectin
AMPK where/when are they synthesized
adipocytes & stomach cells
low levels of glucose, free fatty acids (FFA), or branched-chain amino acids (BCAA)
low levels of glucose, free fatty acids (FFA), or branched-chain amino acids (BCAA) stimulate the activation of
hypothalamic AMPK
Which hormones activate mTOR ?
insulin or leptin
mTOR where/when are they synthesized?
pancreas
adipocytes
response to ample nutrient levels.
describe how the human body adapts to starvation
When they are in starvation mode the body moves to ketone glucose production to produce glucose and lowers the intake of protein degradation. with no muscles our body would die
