cell metabolism 1 Flashcards
what are the three stages of glucose respiration?
- glycolysis
- TCA cycles
- oxidative phosphorylation
what is glycolysis?
oxidation of glucose within cytosol of individual cells generating ATP and NADH
anaerobic process
what are the 6 types of reaction involved in respiration?
redox- electron transfer
ligation(requires ATP)- formation of covalent bond
isomerisation- rearrangement of atoms
group transfer- transfer of functional groups between molecules
hydrolytic- cleavage of bonds by addition of water
addition or removal of functional groups- addition to double bonds or removal to form double bonds
what is the overall equation for glycolysis?
glucose ——–> 2 pyruvate + 2ATP + 2NADH
outline step 1/10 of glycolysis
glucose———-> glucose-6-phosphate(G6P) + H+
ATP ADP
enzyme- hexokinase
type of reaction- group transfer
traps glucose in cell via negative charge
outline step 2/10 of glycolysis
glucose-6-phosphate——>fructose-6-phosphate
enzyme- phosphoglucose isomerase
type of reaction- isomerisation
outline step 3/10 of glycolysis
fructose-6-phosphate—–>fructose-1,6-bisphosphate
ATP ADP
enzyme- phosphofructokinase
type of reaction- group transfer
outline step 4/10 of glycolysis
fructose-1,6-bisphosphate—>glyceraldehyde 3-phosphate + dihydroxyacetone phosphate
enzyme-aldolase
type of reaction- hydrolytic
(2 high energy compounds)
outline step 5/10 of glycolysis
dihydroxyacetone phosphate——–>glyceraldehyde 3-phosphate
enzyme- triose phosphate isomerase(TPI)
type of reaction- isomerisation
metabolic diseases- TPI deficiency is the only glycolytic enzymopathy that is fatal
outline step 6/10 of glycolysis
glyceraldehyde 3-phosphate–>1,3-bisphosphoglycerate
NAD+ +Pi NADH
enzyme- glyceraldehyde 3-phosphate dehydrogenase
type of reaction- redox and group transfer
(all reactions from here on happen twice due to 2 glyceraldehyde 3-phosphates)
outline step 7/10 of glycolysis
1,3-bisphosphoglycerate——>3-phosphoglycerate
ADP ATP
enzyme- phosphoglycerate kinase
type of reaction- group transfer
outline step 8/10 of glycolysis
3-phosphoglycerate——>2-phosphoglycerate
enzyme- phosphoglycerate mutase
type of reaction- isomerisation
outline step 9/10 of glycolysis
2-phosphoglycerate—–>phosphoenolpyruvate + water
enzyme-enolase
type of reaction- group removal (dehydration)
outline step 10/10 of glycolysis
phosphoenolpyruvate——-> pyruvate
ADP ATP
enzyme-pyruvate kinase
type of reaction- group transfer
what are the 3 fates of pyruvate
alcoholic fermentation
lactate production
acetyl CoA production
outline the 2 steps of alcoholic fermentation
- pyruvate—–>acetaldehyde
H+ CO2
enzyme- pyruvate decarboxylase - acetaldehyde———–>ethanol
NADH + H+ NAD+
enzyme- alcohol dehydrogenase
outline lactate production
pyruvate lactate
NADH + H+ NAD+
enzyme- lactate dehydrogenase
outline how creatine phosphate acts as a buffer
creatine phosphate + ADPcreatine + ATP
enzyme- creatine kinase
outline how acetyl-CoA is produced(link reaction)
pyruvate + HS-CoA-------->acetyl-CoA +CO2
NAD+ NADH
enzyme- pyruvate dehydrogenase complex
occurs in mitochondria
committed to enter TCA cyclewhat is the feature of acetyl-CoA?
high energy thioester linkage which allows donation of the acetate(2C) molecule
what is beri beri?
results from poor PDH(pyruvate dehydrogenase)
damages peripheral nervous system
causes weak musculature and decreased cardiac output
brain is especially vulnerable as it relies on glucose metabolism
low thiamine can cause it due to thiamine being a cofactor for PDH
what does each turn of the TCA cycle produce?
2 CO2
3 NADH
1 GTP
1 FADH2
describe the enzymes involved in the TCA
soluble proteins located in mitochondrial matrix space
what condition is required for TCA cycle to happen?
aerobic
