metabolism Flashcards
coenzymes of metabolism
coenzyme A
is a vitamin B derivative
pantothenic acid (B5]
NADH+H+
nicotinamide adenine dinucleotide - reduced form
FADH2
Flavin adenine dinucleotide - reduced form
transfer hydrogen atoms between a compound being oxidized and one that is being reduced
loss and gain of hydrogen atoms is associated with energy losses and gains
i.e. coenzymes transfer energy between compounds
dietary carbohydrates
sugars (monosaccharides and disaccharides)
e.g. glucose, fructose, galactose, lactose
starches (polysaccharides)
e.g. glycogen, cellulose
glycolysis
anaerobic process
catabolism of glucose
takes place in cytoplasm
when O2 is lacking in glycolysis
glucose– glycolysis— pyruvic acid—- anaerobic pathway— lactic acid
Next step of Pyruvic acid catabolism when oxygen is present
No ATP produced here
formation of acetyl coenzyme A
last step in glucose catabolism
the electron transfer chain
ATP produced in aerobic respiration
34-36 ATP per glucose
2 ATP produced anaerobically in glycolysis
grand total of 36-38 ATP per molecule glucose
glycogenesis
Short term storage of glucose in the liver and muscles in the form of Glycogen
glucose anabolism
excess glucose in the body- can also be converted into lipogenesis
reversible process
glucogenesis
when the liver needs to produce glucose because sugar is low in supply
is stimulated by cortisol and glucagon
A.A
essential amino acids:
the ten amino acids that cannot be synthesized by the body
must be obtained from diet
nonessential amino acids:
the ten amino acids that the body is able to synthesize
complete protein:
contain all the essential amino acids needed by the body
incomplete protein:
protein-rich but lacking in certain essential amino acids
anabolic rx involving amino acids
directed by DNA,
utilizes RNA and ribosomes to link amino acids by peptide bonds and form functional proteins
catabolism of amino acids
deamination:
removal of the amino group of an amino acid
amino group (NH2)converted to ammonia (NH3)
fate of ammonia:
hepatocytes convert ammonia to urea excreted in urine
utilization of deaminated amino acids: enter into Krebs cycle
dietary lipids
triglycerides
saturated fats
contain single carbon bonds only so every carbon is bound to the maximum # of hydrogen (saturated with hydrogen)
unsaturated fats
contain double bonds between one or more carbons and thus do not contain the maximum # hydrogen
lipid metabolism
lipolysis (stimulated by epinephrine, norepinephrine, and cortisol )
lipogenesis (stimulated by insulin )