L34 - cell metabolism

Question 1

outlines

Answer 1

• how chemical transformations within metabolic pathways can be used to generate + store energy
• glycolysis + gluconeogenesis
• tricarboxylic acid (TCA) cycle
• electron transport system
• glycogen synthesis and breakdown
• fatty acid synthesis + break down

Question 2

what is metabolism?

Answer 2

interconversion of biomolecules using chemical reactions

Question 3

types of catabolic reactions (degradative)?

Answer 3

1. production of chemical energy (ATP) and ion gradients
2. production of mechanical energy (muscle contraction)
3. production of reducing equivalents (NADH, NADPH)
4. production of biosynthetic precursors

Question 4

types of anabolic reactions? (biosynthetic)

Answer 4

1. storage of energy
2. production of macromolecules and cellular structures

Question 5

Gibbs free energy of reaction

Answer 5

∆𝐺= ∆𝐺°+𝑅𝑇 ln ([𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠])/([𝑟𝑒𝑎𝑐𝑡𝑎𝑛𝑡𝑠])

Question 6

what is ∆𝐺° ?

Answer 6

Gibbs free energy under standard conditions

Question 7

what is the temp and R of the Gibbs free energy of reaction?

Answer 7

• temp = ~ 310.15K (~37 degrees)
• R = 8.314

Question 8

what are biological reactions in a state of?

Answer 8

state of flux (chemicals are interconverted through a successive series of steps)

Question 9

what are endothermic reactions often driven by?

Answer 9

• ATP
• pyrophospate hydrolysis (removal of products)

Question 10

ATP to ADP + Pi =

Answer 10

30.5 KJmol-1

Question 11

ATP to AMP + PPi =

Answer 11

45.6 KJmol-1

Question 12

K eg for [ATP]/[ADP][Pi] =

Answer 12

500 M-1 in the cell

Question 13

what can hydrolysis of ATP do to the equilibrium constant?

Answer 13

change the equilibrium constant of a coupled reaction by 10^8 per hydrolysed ATP molecule

Question 14

what does metabolism need to balance?

Answer 14

energy (ATP), reducing agents and the amounts of small molecules

Question 15

stage 1 of glycolysis (3 steps)

Answer 15

• ## occurs in cytosol