Unit 3.2 Flashcards
Metabolism
all the biochemical reactions that occur within an organism, including anabolic
and catabolic reactions
Anabolism
energy requiring reactions whereby small molecules are built up into larger
ones
Aerobic catabolism
chemical reactions that break down complex organic compounds into
simpler ones, with the net release of energy
Anaerobic catabolism
the breakdown of complex chemical substances into simpler
compounds, with the release of energy, in the absence of oxygen
CarbLoading
Endurance athletes eat lots of starchy foods, rich in complex carbohydrates the day before before a big event or race. This is known as carb loading.
This is to ensure that their glycogen levels are at 100% in time for the race. (more energy)
State what glycogen is and its major storage sites.
Glycogen is stored in the liver and skeletal muscles and is the body’s preferred energy source in medium to high intensity exercise when working without the presence of oxygen
It is a polysaccharide made out of glucose
State the major sites of triglyceride storage
Stored in adipose tissue (fat) and skeletal muscles and are found in blood
Outline glycogenolysis
Is the breakdown of Glycogen, stored in the liver and muscles, back into glucose, which can be used to create energy.
Lipolysis
Is the breakdown of lipids, stored as triglycerides in the adipose tissue, into glycerol and free fatty acids.
Explain the role of insulin and muscle contraction on glucose uptake during exercise
During exercise, the greater amount of muscle contraction requires increased amounts of
glucose to provide the energy required for contraction
Glycogen is stored in the muscles, and it is the main source of fuel during strenuous,
short-term exercise
Blood-borne-glucose and free fatty acids that come from adipose tissue are usually used
during prolonged exercise
Insulin stimulates glucose uptake from the blood into skeletal muscle
During exercise, insulin levels fall, and glucagon and adrenaline levels rise, so overall:
- Less glucose is absorbed by the liver
- More glycogenolysis occurs causing the release of more glucose into the blood
Therefore, blood glucose is absorbed by muscles during exercise
Outline the functions of glucagon and adrenaline during fasting and exercise
Glucagon fasting:
After a period of fasting the blood glucose levels will drop
Glucagon is a hormone that is released from the pancreas to stimulate glycogenolysis and lipolysis
This accelerates the conversion of glycogen to glucose in the liver
Adrenaline fasting:
During a period of fasting, the blood glucose levels will drop.
Adrenaline is released as part of a sympathetic nervous system response.
This accelerates the conversion of glycogen to glucose in the liver.
Glucagon exercise:
Glucose is used to create energy as part of aerobic respiration. During exercise the blood glucose levels will drop.
Glucagon is a hormone that is released from the pancreas to stimulate glycogenolysis
This accelerates the conversion of glycogen to glucose in the liver
Adrenaline exercise:
During exercise there is an increased demand for glucose within the skeletal muscle cells for respiration to occur.
Adrenaline is released as part of a sympathetic nervous system response.
This accelerates the conversion of glycogen to glucose in the liver.
Explain the role of insulin in the formation of glycogen and the accumulation of body
fat
⟶ insulin is secreted from the beta cells in the pancreas in response to high levels of sugar
in the blood
⟶ it transforms glucose to glycogen and stores it in the liver and in muscles
⟶ it transforms glycerol and fatty acids to lipids, and amino acids into proteins, it stores this
in the body
⟶ insulin stops glycogenolysis, lipolysis and the breakdown of proteins into amino acids
⟶ things build up and get stored (anabolism) instead of breaking down
⟶ insulin helps to maintain a normal level of sugar in the blood
