Metabolism Flashcards
In Glycolysis: What are the Carriers.
ATP, NADH, Acetyl CoA
What is the NET ATP from Glycolysis?
2
What is the NET ATP from TCA?
2
What is the NET ATP from ETC?
28
Draw the Process of Pyruvate in Anaerobic Conditions
What Happens when theres too much Lactate?
body pH drops, too acidic
What other Sugars other than Glucose can be used?
galactose and fructose from adipose tissues or liver
Describe Lactose Intolerance.
- lactose is too big to pass through digestive tract lining
- must be broken into galactose and glucose by lactase
- if lactase is underproduced
- lactose remains in GI tract
- becomes fermented by bacteria
Describe Symptoms of Lactose Intolerance
farting, diarrhoea, cramps, bloating, nausea
Describe Galactosemia
inherited autosomal recessive disorder
- deficiency of galactose-1-phosphate uridyl transferase
- in the eye..
- aldose reduces galactose into galacitol
What are the Symptoms of Galactosemia
cataracts in the eye, enlargement of liver, CNS failure
HOW does Fluoride kill cariogenic bacteria?
inhibits Enolase
- enzyme needed to convert 2-phosphopglycerate into PEP
- think glycolysis
State and Describe 4 Mechanisms in which Metabolism can be Regulated.
- Allosteric Regulation
- enzyme activity can be inhibited by binding an effector molecule at a site other than the enzyme’s active site - Association with Regulatory Protein
- Covalent Modification
- phosphorylation - Sequestration
- alters accessibility of reactions, products and substrates
What are the 4 Main Enzymes in Glycolysis?
Hexokinase
Phosphofructokinase
Pyruvate Kinase
Pyruvate Dehydrogenase
How is Hexokinase Regulated?
Allosteric Regulation
- inhibit Glucose into G-6-P
2 Ways in Which the Activity of Phosphofructokinase is Reduced?
- Allosteric Regulation by ATP
- ATP is overproduced
- binds to allosteric site
- lowers the PFK affinity - Sensitivity to pH
- high acidity reduces activity
- prevents formation of lactic acid
How Can Phosphofructokinase be Activated
by Fructose-2,6-Bisphosphate
- binds to allosteric site
- increase enzyme affinity for F-6-P
- reduces affinity for ATP
How is the Activity of Pyruvate Kinase Regulated?
allosteric regulation and covalent modification
How is Pyruvate Kinase Activated?
Fructose-1,6-Bisphosphate
How is Pyruvate Dehydrogenase Regulated?
allosteric regulation and covalent modification
has 2 limiting sited
E2 Transacetylase - limited by Acetyl CoA
E3 Dihydrolipolydehydrogenase - limited by NADH
What are the Main Enzymes in TCA?
citrate synthase
isocitrate dehydrogenase
a-ketoglutarate dehydrogenase
Draw out Glycolysis
Where does Glycolysis Occur?
in the cystol of the cell
What are the 5 Main Stages in Glycolysis and where do they occur, using enzymes?
1) Irreversible Phosphorylation
- hexokinase
2) Isomerisation - Aldose to Ketone
- phosphoglucose isomerase
3) Irreversible Phosphorylation
- phosphofructose kinase
4) Cleavage
- Aldose
5) Isomerisation
- Triose Phosphate Isomerase
- DHAP into GAP
Draw out Link Reaction
Where does Link Reaction Occur?
matrix of the mitochondria
Draw out TCA Cycle
What are the 9 Steps of TCA Cycle?
- Condensation
- Condensation
- Hydration
- Oxidative Decarboxylation
- Oxidation Decarboxylation
- Substrate Level Phosphorylation
- Dehydrogenation
- Hydration
- Dehydrogenation
What is the only sugar the brain will use?
glucose
Draw Glycolysis.
Draw Glycolysis in the liver and in the muscles.
What 2 Enzymes are needed at a branch point?
Transferase Enzyme - transfers 3 glucose units from one end to another
Amylo-a-1,6-glucosidase - hydrolyses the single glucose unit left behind
How does Adrenaline and Glucagon work? Draw it out. (cAMP)
Draw Out Glycogenesis
What is Anderson’s Disease?
deficiency of branching enzyme
liver failure and death in first year of life
Insulin activates PK, what is this?
protein kinase
how does protein kinase work, draw it out.
How does Gluconeogenesis work?
the opposite of glycolysis, bypassing the irreversible steps
Draw out the Steps of Gluconeogenesis
Where does Gluconeogenesis Occur?
in the liver
What are the precursors for Gluconeogenesis?
lactate
glycerol
amino acids
Draw out the roles of lactate and glycerol.
lactate into pyruvate by lactate dehydrogenase
glycerol + ATP into glycerol phosphate + ADP + H+ into DHAP
by glycerol kinase and then glycerol phosphate dehydrogenase
State Steps of ETC.
- NADH-Q reductase complex
- succinate dehydrogenase
- cytochrome c reductase complex
- cytochrome c oxidase complex
What is the Proton Motive Force?
change in ph + change in charge gradient
Describe Structure of ATP Synthase
two functional domains = F0 and F1
Describe F0 from ATP Synthase
- imbedded in the inner mitochondrial mem
- has a proton pore
- has multiple subunits
C subunits rotate
- has aspartic acid in the middle
- when in contact with membrane = neutral charger
- when in contact with a unit = negative charge
B subunit stuck on the outside
- 2 half channels
- hydrogen diffuses in Galway
How does F0 work?
- aspartic acid in contact with a complex = negative charge
- c subunits cant move
- due to chemical gradient, protons move in
= positive charge - c subunit rotates clockwise
- repeats
What is the F1 Complex, Explain Subunits?
contains the catalytic activity of the synthase
5 Subunits
3 a, 3 b, 1g
- only gamma rotates and determines the state
- open state = ATP release
- tense state = ATP produced
Describe Muscle Shuttle
- e- from NADH transport into mitochondria via glycerol-3-phosphate shuttle
Draw Muscle Shuttle.
How does ATP synthase travel in the Heart and Liver
Malate-Aspartate Shuttle
Draw Malate-Aspartate Shuttle.
NADH donates e- to oxaloacetate to form malate
- malate dehydrogenase
malate goes across the mitochondrial membrane
malate back into oxaloacetate
- mitochondria malate
glutamine + oxaloacetate
= aspartate
- aminotransferase
What is the Purpose of the Pentose Pathway?
to oxidise glucose to create NADPH
Draw out Pentose Pathway
What is a Toxic Bi-Product of Oxidative Phosphorylation, what percents is it found in?
ROS
1%
How do you get rid of ROS?
NADPH
- reduced glutathione:::
- hydrogen peroxide into water using glutathione peroxidase
- oxidised glutathione:::
- uses glutathione reductase and NADPH to become reduced
= repeat process
What Happens if you have a Deficiency in G-6-P Dehydrogenase?
no ability to produce NADPH
= no detoxification
- problem when under oxidative stress
BUT INHIBITS MALARIA PARASITE
