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Y Ben's Biochemistry I > Bioenergetics > Flashcards

Flashcards in Bioenergetics Deck (21)
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1
Q

What are the two components which make up adenosine?

A

ribose and adenine

2
Q

Via what kind of bond do phosphates attach to adenosine?

A

phosphate ester bond

  • the OH of adenosine’s free CH2OH group bonds to a phopshate
3
Q

What bond holds the most energy in ATP?

And what is the general term for such a high energy bond?

A

the anhydride centered around the O between two Ps

macroergic bonds are high energy bonds

4
Q

What is the energy released per mole of dephosphorylated ATP?

A

30 kJ per mole

5
Q

How can more ATP be formed from only free ADPs without the presence of free phosphates?

A

via the enzyme adenylyl kinase which converts 2 ADP into one ATP and one AMP

6
Q

What is the reversible equation of the creatine system?

A

ATP + Creatine <—> ADP + Creatine Phosphate

7
Q

What kind of special high energy bond can creatine form?

Where on the molecule?

A

Phosphoamide

  • a macroergic bond between phosphate and creatine
  • forms when phosphate bonds with the terminal amino group on creatine
8
Q

What are the overall inputs and outputs of glycolysis?

A

2 ATP in (forms two 1,3 BPG)

4 ATP out (two for each BPG)

plus

2 Pyruvates or Lactic Acids (anaerobic)

(and 2 NADH plus 2 H+ )

9
Q

What are the 2 important molecules involved in the ATP forming steps of glycolysis?

And what kind of ATP creation is this?

A

1,3 - Bisphosphoglycerate

and

Phosphoenolpyruvate

  • take part in substrate level phosphorylation
10
Q

What kind of bond is the high energy bond in 1,3 BPG?

A
  • a macroergic anhydride between glycerols C1 and phosphate
11
Q

What is the overall reaction of the first ATP producing step of glycolysis?

A

1,3 BPG + ADP —> 3 PG + ATP

  • notice it is irreversible
12
Q

What is the high energy bond of the 2nd ATP producing step of glycolysis?

A

enol-ester

  • between the central carbon of the enolpyruvate portion of PEP and its phosphate
13
Q

What is the reaction equation for the 2nd ATP producing step of glycolysis?

And what is the fate of the dephosphorylated molecule?

A

PEP + ADP —> ATP + enolpyruvate

  • note it is irreversible
  • enolpyruvate is tautomerized to pyruvate
14
Q

Where does substrate level phosphorylation happen in the Krebs cycle?

A

GDP is phosphorylated to GTP via Succinyl-CoA

15
Q

What are the important products of the krebs cycle which become substrates for the reactions of the ETC?

A

NADH

H+

and FADH2

16
Q

What complexes are involved in NADH+ transportation in the respiratory chain?

And what do these complexes do to help ATP synthase work?

A

I, III and IV

(II takes up FADH2 only)

  • they pump protons into the intermembrane space to create and H+ concentration gradient which drives ATP synthase’s phosphorylation of ADP

(complex II does NOT pump protons in)

17
Q

What is the function of coenzyme Q within the ETC?

A
  • acts as an electron carrier from complex I to II to III
18
Q

Where does oxygen fit into the ETC?

A

It is reduced to water at complex IV

19
Q

What poisons can inhibit the respiratory chain and where?

A

oligomycin - inhibits Fo complex of ATP synthase

HCN - inhibits complex IV

20
Q

What happens to the respiratory chain when there is an abundance of ATP?

What is this process called?

A

Acceptor Control

  • since there is less ADP for ATP synthase to use, the respiratory chain slows down
21
Q

What do “uncouplers” do?

What are two examples?

A
  • they dissipate the proton gradient between the IM space and the mitochondrial matrix
  • this ‘uncouples’ the ETC from its ability to drive ATP synthase

D-Nitrophenol binds to H in IM space and carries it to matrix

Thermogenin in brown fat uncouples for the purpose of heat creation