Epinephrine, also known as adrenaline, is a hormone and neurotransmitter that is synthesized in the body from the amino acid tyrosine. Tyrosine is a non-essential amino acid, which means that it can be synthesized in the body from phenylalanine, another essential amino acid. The synthesis of epinephrine occurs in two main steps:

1. Hydroxylation of tyrosine: Tyrosine is converted into dihydroxyphenylalanine (DOPA) by the enzyme tyrosine hydroxylase. This is the rate-limiting step in the synthesis of epinephrine.
2. Decarboxylation and further hydroxylation: DOPA is then decarboxylated to form dopamine, which is further hydroxylated to produce norepinephrine. Norepinephrine is the immediate precursor of epinephrine.
3. Formation of epinephrine: Norepinephrine is methylated by the enzyme phenylethanolamine N-methyltransferase (PNMT) and converted into epinephrine.

The other amino acids listed are not directly involved in the synthesis of epinephrine:

1. Valine and Leucine are branched-chain amino acids that are primarily involved in the metabolism of muscles and energy production.
2. Cysteine is a sulfur-containing amino acid that is important for the synthesis of proteins with disulfide bridges and is a precursor for other molecules like glutathione and taurine, but not directly involved in the synthesis of epinephrine.

Glycolysis is a metabolic process that occurs in the cytoplasm of the cell. The process is central to the conversion of glucose into energy in the form of adenosine triphosphate (ATP) and is a fundamental part of cellular respiration.

1. Cytoplasm: Glycolysis takes place in the cytoplasm of the cell. The cytoplasm is the fluid-filled space between the cell membrane and the nucleus (and other organelles in eukaryotes) where various metabolic reactions occur. This process involves a series of enzymatic reactions that break down one molecule of glucose into two molecules of pyruvate, yielding two net molecules of ATP and two molecules of NADH (a reduced form of nicotinamide adenine dinucleotide) along with some other byproducts.

2. Mitochondrion: Although glycolysis does not occur in the mitochondrion, the mitochondrion plays a crucial role in the subsequent stages of glucose metabolism. After glycolysis, the pyruvate molecules produced in the cytoplasm can be transported into the mitochondria, where they are further processed in the citric acid cycle (also known as the Krebs cycle or TCA cycle) and the electron transport chain to produce more ATP.

The enzyme phosphatidate phosphatase converts phosphatidic acid to diacylglycerol during synthesis of triacylglycerides.

The function of adipose tissue is the storage of fatty acids as triacylglycerols in times of plenty and the release of fatty acids during times of fasting or starvation.

Fatty acids taken in by adipocytes are stored by esterification to glycerol-3-phosphate. Glycerol-3-phosphate is derived almost entirely from the glycolytic intermediate dihydroxyacetone phosphate through the action of glycerol-3-phosphate dehydrogenase. Glycolytic enzymes are active in adipocytes during triglyceride synthesis, but those of glycogen degradation (low levels in adipocytes) and gluconeogenesis (ie, glucose-6-phosphatase) are not.

Glycerol kinase is not present to any great extent in adipocytes, so that glycerol freed during lipolysis is not used to reesterify the fatty acids being released.

The enzyme triacylglyceride lipase is turned on by phosphorylation by a cyclic AMP-dependent protein kinase following epinephrine stimulation.

Epinephrine causes increased blood glucose level due to: 1. Increased glycogenolysis in liver and muscle 2. Activation of phosphorylase 3. Inhibition of glycogen synthesis in liver

Vitamin C deficiency is due to defect of Lysyl hydroxylase