Biochemistry L04 Enzymes and Cellular Energy Flashcards Preview

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Flashcards in Biochemistry L04 Enzymes and Cellular Energy Deck (10):
1

Name 3 factors that affect enzyme activity

Temperature
pH
Substrate concentration

2

Define substrate

The reactant of a catalysed reaction

3

Define active site

Site of an enzyme that binds to the substrate in a configuration that forces it to resemble the transition state. It is highly specific

4

Define activation energy

The energy barrier that a reaction must overcome in order to occur

5

What is the difference between an endergonic and exergonic reaction?

Energonic reactions absorb energy
Exergonic reactions release energy

6

If a reaction has ΔG = -30kJ/mole, is it endergonic or exergonic?

Exergonic

7

How does a catalyst affect ΔG, Ea (activation energy) and the equilibrium of a reaction?

No change in ΔG
Ea decreases
No change in equilibrium

8

What is ΔG of ATP hydrolysis?

-29.3kJ/mol

9

Name 1 molecule other than ATP that can be used as cellular energy currency (or are precursors of ATP)

NADH
FADH2
Acetyl CoA
GTP

10

What is the transition state?

The intermediate state between reactant and product. The enzyme's active site has a higher affinity for the TS than the reactant, so on reactant binding induces a conformational change in the reactant towards the TS.
The TS is the highest point of energy in the reaction