define anabolism

• endergonic (pos. ΔG)
• synthesis process in body

Define catabolism

• exergonic (neg. ΔG)
• degradative processes of body

Define metabolic pathway

series of consecutive chemical rxns in which specific substrate(s) are converted into specific product(s)

• with few exceptions, each reaction in pathway catalyzed by enzyme
• each pathway has commited step which is usually irreversible and rate limiting
• occurs at specific site in cell
• regulated AT RATE LIMITING STEP

Types of pathways

linear

branched

cyclic

define phototrophs

obtain energy from oxidation of organic compounds supplied in diet (respiration)

oxidation of glucose (-2800 kJ) and fatty acids       (-12,000 kJ) supplied via the diet

Calories for gram of protein

4 kcal/gram of protein (much more complicated because when it is broken down, produces N product, which becomes ammonia, which is a source of energy)

glucose

fatty acids

amylase (salivary, pancreatic)

brush border enzymes

Substances that break down fats into FA's

pancreatic juices

bile

Rxn of glucose being broken down to CO2

We must use specific small reactions to get small packets of energy. This energy is used to synthesize ATP (couple rxn with ATP synthesis). Any reaction that is coupled to ATP synthesis is irreversible.

33 kJ/mole

• loss of electrons
• loss of hydrogen
• addition of oxygen

• ferrous → ferric + e
• cuprous → cupric +e

1. oxidation involves breaking C-H bond
2. H bond removed with both electrons (hydride ion)
   • acts as a packet of energy (extremely reactive)
3. carbon will become positive
4. intermediate of C compound will rearrange by losing a proton

• alkane converted to alkene (ex: succinate to fumarate)
• alcohol via dehydrogenase produces aldehyde/ ketone and hydrogen ion (positive ion)
• aldehyde via dehydrogenase to carboxylic acid
• decarboxylation of alpha keto acid to carboxylic acid and carbond dioxide

NAD

NADP

FMN

FAD

• develop pelagra (3 D symptoms)
  • dermititis
  • diarrhea
  • dementia
  • if not treated, DEATH

type of coenzyme of flavoproteins

• oxygenase- transfer reducing equivalents directly to molecular oxygen with formation of hydrogen peroxide (ex: D AA oxidase)
• dehydrogenases- oxidize substrates (ex: fatty acyl CoA DH)
• reductases- reduce substrates (ex: glutathione reductase)

ALL INVOLVE REACTION WITH OXYGEN EITHER DIRECTLY OR INDIRECTLY!!

• FAD/FMN
• FMN./FAD. (semiquinone form)
• FADH2/FMNH2

• carry acyl groups
• sulfhydryl group react with carboxylic acid to form thiol ester
  • thiol ester bond is high energy
  • represents activated state of CoA that can be transferred directly to appropriate acceptor molecule

Structurally, what is the difference between ACP and CoA-SH

pyrophosphate gropu added to alcohol group of a thaimine

• act as prosthetic group for
  • transketolase
  • alpha keto acid dehydrogenase (decarboxylation of alpha keto acids)
    • non-oxidative (needs only one enzyme)
    • oxidative (need a bunch of other enzymes)

• non-oxidative produces aldehyde and carbon dioxide
• oxidative produces carboxylic acid, carbon dioxide, and two electrons (via enzyme complex called dehydrogenase)

• decarboxylase with TPP coenzyme
• transferase composed of lipoic acid coenzyme with a Lys attached to the carbonyl end
• dihydrolipolyl dehgydrogenase with FAD coenzyme

1. add alpha keto acid to TPP in decarboxylase
2. carbon dioxide leaves decarboxylase-TPP complex
3. the RC=O group binds to lipoic acid in trasnferase complex
4. CoA-SH pick up R=CO, causing two H's to come back to lipoic acid in transferase
5. dihydrolipoyl dehydrogenase picks of hydride ions via FAD as its coenzyme
   1. this will reform the ringed structure of the lipoic acid within transferase
6. to regenerate FAD in dihydrolipoyl dehydrogenase, NAD will pick up the hydrides from FADH2

• pyruvate dehydrogenase
• alpha keto glutarate dehydrogenase
• alpha keto branched chain dehydrogenase

• NADH is used to fuel the ETC
• ETC will pass electron to O2 to produce H20
• ETC will also produce energy that will fuel the synthesis of ATP