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Flashcards in bcm29 Deck (18):
1

how gluconeogenesis by pass the two irreversible steps of glycolysis?

using different enzymes
Fructose bis phosphatate
pyruvate carboxylate (pyruvate ->oxalocacetate)
pep carboxylase oxacloacetate -> pep

2

what does gluconeogensis allow?

cell to make glucose from protein but not lipid
starvation response.

3

how do plants make lipid-> glucose

use glycoylate cycle
short cut

4

where does glycoxylate cycle occur

specilised peroxisomes called glyoysomes
found in seedlings so fat can be used for cell walls

5

what is the pentose phosphate pathway

mulitfunctional shunt anabolic shunt from glycolysis

6

what is the first stage of the pentose phosphate pathway

oxidation step
generates NADPH
glucose 6p> gluconate 6p > ribulose 5-p

7

what can be made from the ppp

nadph for lipid synthesis
ribulose bp for dark reactions of photosynthesis
ribose for rna and dna synthesis
gap, fructose p and fructose 6p for glucose

8

what are the two main stages of the pentose phosphate pathway?

oxidative stages generate nadph
non oxidative stage makes 5 carbon sugars

9

how does metabolism differ from what would happen anyway?

conserves free energy as atp iin a way burning glucose in o2 doesnt and flux is faster at 298k

10

what is flux

carbon flow

11

what does rate of flux depend on

enzyme availibity and activity

12

what happens to flux if there is no pfk activity

still some flux if o2 is presetn as in high o2 reactions of glycolysis krebs and op are all spontaenous

13

what does existence of flux depend on

thermodynamics

14

what does enzyme regulation maintain

homeostasis in the face of externally imposed changes in flux

15

what do all metabolic processes depend on

thermodynamic disequilibrium

16

what does heterotroph metabolism couple

spontaneous oxidation of reduced carbon to non spontaneous formation of biopolymers

17

what does iron bacteria metabolism couple

spontaneous rusting of ferrous ions to non spontaneous formation of biopolymers

18

what does phototroph metabolism couple

spontaneous cooling of balls of space plasma
non spontaneous formation of biopolymers