Glycolysis Flashcards
various biochemical processes responsible for the formation, breakdown and interconversion of carbohydrates in living organisms
Carbohydrate Metabolism
generation of cellular energy
sausage shape
convoluted
Mitochondria
enzyme in mitochondria responsible for production of ATP
ATP Synthase
composition of outermost layer of mitochondria
50% protein
50% lipid
composition of innermost layer of mitochondria
80% protein
20% lipid
beginning of metabolism
digestion
action of salivary amylase
starch & glycogen -> polysaccharides
action of pancreatic amylase
polysaccharides -> disaccharides
action of S.I
disaccharides -> simple sugars
stops enzyme action in stomach
gastric juice
enzymes in S.I
maltase, sucrase, lactase
reaction of digestion of carbohydrates
hydrolysis
has greatest no. of ways to utilize glucose
storage
glucose -> glycogen
releases free glucose from glycogen when blood glucose levels are low
liver
utilizes stored glycogen for synthesis of ATP during exercise
skeletal muscle
reoxidized to continue glycolysis
NADH
Starch + Salivary Amylase +H2O
Maltose + Dextrins
Starch + Pancreatic Amylase + H2O
Maltose + Isomaltose
Maltose + Maltase + H2O
Glucose (2)
Isomaltose + Maltase + H2O
Glucose (2)
Lactose + Lactase + H2O
Glucose + Galactose
Sucrose + Sucrase + H2O
Glucose + Fructose
breakdown of all compounds
catabolism
Common Monosaccharides
glucose
galactose
fructose
Disaccharides
sucrose ( glucose + fructose)
maltose (glucose + glucose)
Lactose (glucose + galactose)
Polysaccharides
Starch Dextrin Cellulose Pectin Glycogen
Absorption of Monosaccharides
Simple Diffusion
Facilitated Transport
Active Transport
Accdg. to concentration gradient
Fructose and pentoses
Simple Diffusion
GLUT5: glucose, galactose and fructose
Facilitated Transport
SGLT (Sodium Glucose Transporter)
glucose and galactose
Active Transport
Pathways for Glucose Utilization
Oxidation
Provides other Compounds
Storage
Excretion in urine
for production of energy
Oxidation
Provides other compounds:
Carbohydrates
Glycerol 3-phosphate
Acetyl CoA
Non essential AA
storage in adipose
triacylglycerol
Major Pathways in oxidation of glucose
Glycolysis
Kreb’s Cycle
Minor Pathways in oxidation of glucose
Hexose monophosphate pathway
Uronic acid pathway
Central roles of glucose
storage
oxidation via glycolysis
oxidation via pentose phosphate pathway
synthesis of structural polymers
storage
glycogen, starch, sucrose
oxidation via glycolysis
pyruvate
oxidation via pentose phosphate pathway
ribose 5-phosphate
synthesis of structural polymers
extracellular matrix
cell wall polysaccharides
- a pathway used by all body cells
- converts glucose to pyruvate
- an example of anaerobic fermentation
- oxygen is not necessary
- mostly endergonic reactions
Glycolysis
produced by glycolysis
conjugate base of carboxylic acids and ketones
has negative charge
completely oxidized to CO2 and H2O in mitochondria (aerobic)
Pyruvate/ pyruvic acid
formula of pyruvate
CH3COCOOH-
ending of all cycles
ATP
Dinucleotide Phosphates
ATP
ADP
AMP
products of Hydrolysis of phosphates
ATP - ADP + Pi + e
ADP - AMP + Pi + e
ATP + 2 H2O - AMP + 2Pi + e
NAD
nicotinamide
protection of RBC
used in ETC
NADH reduced
FAD
riboflavin
FADH2 reduced
Coenzyme A
CoA + SH
must be attached to acetyl group to form Acetyl Coa
start of TCA
Acetyl CoA
makes CoA active
SH
CHO metabolism
uridine triphosphate (UTP)
Protein metabolism
guanin triphosphate (GTP)
Phosphorylation reactions
Reaction 1, 3,7,10
Isomerization Reactions
Reaction 2, 5
Oxidation Reaction
Reaction 6
Cleavage Reaction
Reaction 4
Shift of Phosphoryl group
Reaction 8
Dehydration reaction
Reaction 9
Intermediate Products
Glucose Glucose 6-phosphate Fructose 6-phosphate Fructose 1,6- biphosphate Glyceraldehyde 3-phosphate + Dihydroxyacetone phosphate Glyceraldehyde 3-phosphate 1,3 - Biphosphoglycerate 3 - phosphoglycerate 2-phosphoglycerate Phosphoenolpyruvate Pyruvate Lactate (anaerobic)
Enzymes
Hexokinase phosphohexose isomerase Phosphofructokinase - 1 Aldolase Triose phosphate isomerase Glyceraldehyde 3-phosphate dehydrogenase Phosphoglycerate kinase phosphoglycerate mutase enolase Pyruvate kinase
phosphorylation of glucose ensures that pathway intermediates remain in the cell
phosphorylation occurs in C6, as C1 is a carbonyl group (phosphorylation only takes place in hydroxyl group)
Reaction 1
Isomerization moves carbonyl to C2
Reaction 2
C-1 now a hydroxyl group can be phosphorylated
ensures both products of C-C cleavage bond are phosphorylated
interconvertible
Reaction 3
carbonyl group at C2 facilitates cleavage
Reaction 4
aldose
glucose 6-phosphate
ketose
fructose 6-phosphate
interconversion of 2 products into single pathway
reaction 5
oxidative phosphorylation of glyceraldehyde 3-phosphate produces NADH - prerequisite for ATP production in 7
Reaction 6
remaining phosphoryl group moves from C2 to C3
reaction 8
alcohol
3-phosphoglycerate
priming reactions
Reaction 1, 3
oxidative phosphorylation reaction
produces NADH
Reaction 6
ATP forming reactions
Reaction 7,10
All carbohydrates enter
glycolysis
Carbohydrates enter in muscle via
hexokinase
D-galactose enters:
Glucose 1-phosphate
Lactose becomes:
D-Galactose
D- Glucose
Trehalose becomes
D-Glucose -> Glucose 6-phosphate
Sucrose becomes:
D-glucose -> Glucose 6-phosphate
or
D-fructose -> Fructose 6-phosphate
Fructose becomes:
Fructose 1-phosphate -> Glyceraldehyde 3-phosphate + Dihydroxyacetone phosphate
D-Mannose becomes
Mannose 6-phosphate -> Fructose 6-phosphate
Dihydroxyacetone derived from glucose carbon
1,2,3
Glyceraldehyde 3-phosphate derived from glucose carbon
4,5,6
Pyruvate in under hypoxic or anaerobic conditions
fermentation to ethanol in yeast
2Ethanol + 2CO2
Pyruvate under anaerobic conditions
fermentation
vigorous contraction
erythrocytes
2 Lactate
Pyruvate under aerobic conditions
Acetyle CoA -> 4CO2 + 4H2O
refers to the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose, which then returns to the muscles and is metabolized
aka lactic acid cycle
Cori cycle
irreversible reactions in Glycolysis
Hexokinase
Phosphofructokinase
Pyruvate kinase
controls or inhibits PFK
ATP (allosteric inhibitor)
binding sites of allosteric enzymes
substrate site
allosteric site
controls or inhibits hexokinase
Glucose 6P (feedback inhibition) Fructose 6P (if PFK is inactive)
inhibits PFK
ATP
Acetyl CoA
Alanine
reaction in TCA
decarboxylation
product of fatty acid metabolism
glycerol
too much intake of O2
hyperventilation
effects of hyperventilation
affect conc. of CO2 in blood
comes in contact with H2O, formation of carbonic acid
Lactate makes blood:
acidic
only pathway where RBC gets energy or is activated
glycolysis
condition of deficiency of enzyme in glycolysis
Hemolytic anemia
formation of bubbles
CO2
site where glycolysis takes place
cytosol
location of ATP synthase
inner membrane