Exercise physiology Flashcards
What is a concerning outcome of insufficient carbohydrate breakdown?
Ketosis - a byproduct of carbohydrate breakdown is a primer for fat metabolism. Insufficient carbohydrate breakdown, either through diabetes or glycogen depletion through inadequate intake or excessive excercise, results in incomplete fat breakdown and the accumulation of ketone bodies (acetoacetate and beta-hydroxybuterate)
What is the role of LDL?
Transport
What is the role of cholesterol?
Involved in building plasma membranes. It is a precursor in synthesizing vitamin D, adrenal gland hormones, estrogen, progesterone and androgen
What is the energy sources in light to moderate exercise, and moderate exercise
In light-to-moderate exercise, FFAs from triacylglycerol and delivered to muscle and intramuscular triacylglycerols.
In moderate exercise, carbohydrates and fats are used in equal proportions. When exercise continues at this level for over an hour, fat catabolism becomes a greater percentage of the energy.
When glycogen reserves become nearly depleted, fat then supplies up to 80% of the energy requirement.
Fat vs carbohydrate use also depends on the intensity of action.
Glycogen plays a preferential fuel for high intensity aerobic exercise
What happens in protein catabolism and what happens to the products?
Protein first degrades to its amino acids. The amino acids then looses its nitrogen (amine group) in the liver (deamination), which then forms urea.
The remaining deaminated amino acid then either converts to a new amino acid, to carbohydrate (gluconeogenesis) or fat (source of acetyl-CoA for FAA synthesis), or catabolizes for energy (citric acid cycle). Urea is then urinated out.
What is the nitrogen balance equation
Nitrogen balance = Nt - Nu - Nf - Ns = 0
Nt = total nitrogen
Nu = nitrogen in urine
Nf = nitrohen in feaces
Ns = nitrogen in sweat
What does a negative nitrogen balance suggest?
This indicates protein is being catabolized for energy. This comes primarily from skeletal muscle.
If there is insufficient carbohydrate or lipids, then protein becomes the primary energy source resulting in loss of lean tissue mass. Thus, the protein sparing role of carbohydrate intake
What is the glucose alanine cycle?
To initiate the cycle, muscle and tissues that catabolize amino acids for fuel generate amino groups—most commonly in the form of glutamate—through the process of transamination. These amino groups are transferred via alanine aminotransferase to pyruvate (a product of glycolysis) to form alanine and alpha-ketoglutarate. Alanine subsequently moves through the circulatory system to the liver where the reaction previously catalyzed by alanine aminotransferase is reversed to produce pyruvate. This pyruvate is converted into glucose through the process of gluconeogenesis which subsequently is transported back to the muscle tissue. Meanwhile, glutamate dehydrogenase in the mitochondria catabolizes glutamate into ammonium. Ammonium moves on to form urea in the urea cycle.
What are the fat soluble vitamins?
A, D, E and K
What are the names of the vitamins?
A, D, E, K
Vitamin C, thiamine (B1), riboflavin (B2), vitamin B6 (pyridoxine), niacin (nicotinic acid), pantothenic acid, biotin, folic acid, and cobalamin (B12)
What are the general function of vitamins?
The contain no useful energy for the body. They serve as essential links and regulators in metabolic reactions that release energy from food. Vitamins also control tissue synthesis and protect the integrity of the cell membranes.
The water soluble vitamins play important roles in energy metabolism.
