Metabolism Overview

• main energy releasing metabolic pathways

  
  

  where does oxidative phosphorylation + electron transport chain occur?

  inner mitochondrial membrane
• main energy releasing metabolic pathways

  
  

  where does TCA cycle (krebs cycle) occur?

  mitochondrial matrix
• main energy releasing metabolic pathways

  
  

  where does β-oxidation occur?

  mitochondrial matrix
• main energy releasing metabolic pathways

  
  

  where does link reaction occur?

  mitochondrial matrix
• main energy releasing metabolic pathways

  
  

  where does glycolysis occur?

  cytoplasm/cytosol of cell

  
• main energy releasing metabolic pathways

  
  

  what are the main energy releasing metabolic pathways?

  • glycolysis + link reaction

  • β-oxidation

  • transamination

  • TCA cycle (krebs cycle)

  • oxidative phosphorylation + electron transport chain

  
• give 3 examples of cofactors

  - metal ions

  - coenzymes

  - prosthetic groups
• give 3 examples of enzyme activators

  - other enzymes

  - change in conditions

  - cofactors
• why are enzyme activators needed?

  - apoenzyme= inactive = precursors

  - holoenzyme= active

  
  

  apoenzyme + activator -> haloenzyme
• what 3 things do metabolic reaction require?

  - Fuel molecules (substrates / Intermediates)

  - Enzyme catalysts

  - enzyme activators
• carrier molecules: Acetyl CoA

  
  

  how many carbons are there in the acetyl group of Acetyl CoA?

  2
• carrier molecules: Uridine Diphosphate Glucose

  
  

  what group does the carrier molecule Uridine Diphosphate Glucose carry?

  glucose
• carrier molecules: Acetyl CoA

  
  

  what is stored in the thioester bond?

  Some of the energy from oxidation of glucose and fatty acids stored here
• carrier molecules: Acetyl CoA

  
  

  what is the high energy bond that bonds the acetyl group to sulfur in Acetyl CoA?

  thioester bond

  
• carrier molecules: Acetyl CoA

  
  

  what is the acetyl group (CH3CO) bonded to in Acetyl CoA?

  sulfur

  
• carrier molecules: NADH, NADPH, and FADH2

  
  

  NADH to NAD+ is reduction. TRUE/FALSE


  FALSE. it is oxidation

  (OILRIG: oxidation is loss, reduction is gain)
• carrier molecules: NADH, NADPH, and FADH2

  
  

  what does FAD from when it accepts 2 Hydrogen atoms?

  FADH2

  
• carrier molecules: NADH, NADPH, and FADH2

  
  

  FAD acts as a hydrogen atom acceptor and accepts 3 Hydrogen atoms. TRUE/FALSE

  FALSE.

  
  

  it does act as a hydrogen atom acceptor however it accepts 2 hydrogen atoms
• carrier molecules: NADH, NADPH, and FADH2

  
  

  what is FAD?

  Flavin adenine dinucleotide
• carrier molecules: NADH, NADPH, and FADH2

  
  

  what is the difference between NADH AND NADPH?

  NADPH is similar to NADH.

  
  

  - NADPH is mostly in anabolic reactions

  - NADH is mostly in catabolic reactions

  
• carrier molecules: Acetyl CoA

  
  

  what group does the carrier molecule Acetyl CoA carry?

  Acetyl group
• carrier molecules: NADH, NADPH, and FADH2

  
  

  NAD+ to NADH is reduction. TRUE/FALSE

  TRUE
• carrier molecules: NADH, NADPH, and FADH2

  
  

  how many hydrogen atoms does NAD+ accept?

  2

  
  

  When two H atoms are transferred to NAD+ from a donor, one proton (H+) is released to solution

  
• carrier molecules: NADH, NADPH, and FADH2

  
  

  what is a hydrogen atom?

  H+ and e-
• carrier molecules: NADH, NADPH, and FADH2

  
  

  NAD+ acts as a hydrogen atom acceptor. TRUE/FALSE

  TRUE
• carrier molecules: NADH, NADPH, and FADH2

  
  

  what is NAD+?


  Nicotinamide Adenine Dinucleotide

  
• carrier molecules: NADH, NADPH, and FADH2

  
  

  what group do the carrier molecules NADH, NADPH, and FADH2 carry?

  electrons and hydrogens
• other high energy nucleotides:

  
  

  what does GTP do?

  drives the synthesis of proteins
• other high energy nucleotides:

  
  

  what does UTP do?

  drives the synthesis of complex sugars
• carrier molecules: ATP

  
  

  what is the functions of ATP?

  • Used directly in cell motility and muscle contraction (motor proteins)

  
  

  • Used in active transport systems e.g. Na+ / K+ pumps

  
  

  • Used in metabolic control - regulates enzyme activity

  (phosphorylation can activate/deactivate molecules)

  
  

  • Used in metabolism to add Pi to metabolic intermediates
• carrier molecules: ATP

  
  

  what does the hydrolysis of ADP form?

  AMP + Phosphate group + energy

  
  

  hydrolysing ATP to AMP releases twice as much free energy as ATP to ADP hydrolysis

  
• carrier molecules: ATP

  
  

  What makes the hydrolysis of ATP energetically so favourable?

  • When the phosphoanhydride bonds are broken, the electrostatic repulsion between phosphate groups is relived.

  -The released phosphate ion is resonance stabilised: increased entropy (ΔS +ve)

  
  

  • We get high bond energy ( when the bond is broken we have at least enough energy to form ATP)
• carrier molecules: ATP

  
  

  what does the hydrolysis of ATP form?

  ADP + Phosphate group + energy

  
• carrier molecules: ATP

  
  

  what PH is ATP chemically stable at?

  PH 6-9
• carrier molecules: ATP

  
  

  what is ATP?

  Adenosine triphosphate

  - it is a high energy nucleotide
• carrier molecules: ATP

  
  

  what group does the carrier molecule ATP carry?

  phosphate
• what are some carrier molecules used in metabolism?

  - ATP

  - NADH, NADPH, FADH2

  - Acetyl CoA

  - Uridine Diphosphate Glucose
• what happens to activated carrier molecules during anabolism?

  the energy stored in the activated carrier molecules are used to form a molecule and make a new one.

  
  

  ( the energy helps the unfavorable reaction occur)
• why is energy stored in carrier molecules during catabolism?

  the reaction is favorable so energy is released
• why is the stepwise breakdown method advantageous?

  • allows pathways to be regulated by regulating specific enzymes

  • allows separate regulation- different forward/reverse pathways

  • allows energy released in each step during catabolism to be stored in activated carrier molecules - by coupling reactions