biochemistry baybeeeeee

• loss of electrons = oxidation, gain of electrons = reduction
• glucagon's role in regulating fatty acid release from triglycerols stored in adipose tissue

  triggers a signaling cascade
• energy tally of beta oxidation

  FAD – FADH = 1.5 ATP

  NAD—NADH = 2.5 ATP

   7 rounds:

              7 FADH

              7 NADH

              8 Acetyl CoA (CAC – 10 ATP)

                          =108 ATP – 2ATP

                                      = net yield of 106 ATP
• ketogenesis


  a metabolic pathway that converts acetyl CoA to ketone bodies, which provide an alternative form of energy for the body. 

  active in fasting conditions.
• how are fatty acids activated by fatty acyl CoA synthetase

  formation of thioester bonds
• purpose of ketone body production

  They can cross the BBB and are converted back into

  Acetyl CoA once in the brain.

  A Buildup of acetyl CoA slows CAC and gluconeogenesis serves as a

  negative feedback to B oxidation
• B oxidation for FA with saturated carbon chains

  • more reduced
  • yields more ATP
  • saturated with hydrogens so one less double bond
• B oxidation for FA with unsaturated carbon chains

  • enters pathway as enoyl CoA hydratase
  • yields 1.5 less ATP
• how will changes in the concentrations of ketone bodies will affect blood pH

  More ketone bodies = more H+ and a drop in pH
• where does B oxidation occur?

  the mitochondria
• where does FA synthesis occur?

  in the cytoplasm and ER of the cell
• what is the role of acetyl-CoA carboxylase and biotin?

  carboxyl carriers
• What is ACP?

  ACP: acetyl carrier protein. ACP transports the growing fatty acid chain between enzyme domains of FAS. analogous to CoA
• what enzymes make up the multi-enzyme complex called FA synthase?

  The enzymes of FAS and ACP

  3-ketoacyl ACP synthase

  3-ketoacyl ACP reductase

  3-hydroxy ACP dehydratase

  2-enoyl ACP reductase

  thioesterase
• energy tally of FA synthesis

  Each round = 2 NADH (2.5 ATP) and 1 ATP

  7 rounds = 42 ATP
• classify lipoproteins by role in cholesterol transport, size, density and name

  VLDLs = very low density

  IDLs = intermediate density lipoproteins

  LDLs = low density lipoproteins

  HDLs = high density lipoproteins

  Larger size has more lipids

  larger = less dense
• what is cholesterol used for

  Hormone synthesis

  Cell membrane development

  Creating bile

  Producing vitamin D
• 4 stages of cholesterol synthesis

  1.     3 acetyl CoA – mevalonate

  2.     Mevalonate – isoprene units

  3.     6-isoprenes – squalene

  4.     Squalene—cholesterol
• compare/contrast initial steps of cholesterol synthesis with ketone synthesis

  -same all the way up to the last step when ketone synthesis does a cleavage, leaving us with aceto-acetate and acetyl CoA

  -happens in the Cytosol of liver vs in the mitochondria
• what enzyme synthesizes mevalonate

  HMG CoA reductase
• how is HMG CoA reductase's activity affected?

  activated by insulin

  inhibited by glucagon

  high levels of ATP activates

  low levels of ATP inhibits

  excess cholesterol inhibits HMG CoA reductase

  and SREBP (which activates HMG CoA reductase)
• 2 general products of amino acid breakdown

  NH3/NH4 and carbon skeleton
• why is the urea cycle necessary?

  to get rid of ammonia (highly toxic)
• how to determine the affect of a deficiency

  anything before blockage = high; anything after=low
• ketogenic

  broken down to acetyl CoA/acetoacetate
• glucogenic

  broken down to CAC intermediates (aKG, succinyl CoA, fumarate, OAA, pyruvate)
• ketogenic amino acids

  leu, lys
• ketogenic and glucogenic enzymes

  phe, tyr, trp, thr, ile
• treatment to manage phenylketonuria


  diet: low phe, suppliment tyr
• 7 metabolic precursors/building blocks of amino acids

  1.     3-phosphoglyglycerate (glycolysis)

  2.     2-phosphoenolpyruvate (glycolysis)

  3.     Pyruvate (glycolysis)

  4.     Ribose-5-phosphate (pentose phosphate)

  5.     Erythrose-4-phosphate (pentose phosphate)

  6.     A-ketoglutarate  (CAC)

  7.     Oxaloacetate (CAC)
• what is an essential amino acid?

  one that can't be synthesized by our own bodies
• essential amino acids

  Arginine (babies only)

  Histidine

  Isoleucine

  Leucine

  Threonine

  Lysine

  Methionine

  Phenylalanine

  Tryptophan

  Valine
• what are amino acids used for

  -translation of proteins

  -building blocks for neurotransmitters

  -building porphyrins
• porphyrins

  General name for the ring structure that is heme. As a family can differ by what ion is in the middle or what is attached outside (heme, cobalamin etc.)

  Made of Glycine + succinyl CoA
• porphyria


  a genetic defect in any of the 8 enzymes used to build porphyrins.