Metabolism Flashcards
To understand the principles behind glycolysis & kreb's, their yields and where they occur
How is ATP generated
Oxidation of glucose, Oxidation of fatty acids, Oxidation of amino acids
Name two main electron carriers
NADH and FADH
Name two common intermediates
pyruvate and Acetyl CoA
Describe oxidation
gain of oxygen, loss of hydrogen and loss of electrons
Describe reduction
Loss of oxygen, gain of hydrogen and gain of electrons
Where does glycolysis occur?
cytoplasm/cytosol
What are the two phases of glycolysis
Preparation and payoff
What is the NET production from glycolysis?
2ATP and 2NADH
Is glycolysis aerobic or anaerobic?
Both
What is the effect of arsenic on glycolysis?
Causes reaction 6 to be skipped
Why does arsenic cause reaction 6 of glycolysis to be skipped?
Arsenic has a similar structure to phosphate, produces an unstable product
What happens to the NET production of glycolysis if reaction 6 is skipped?
NO NET ATP
What is the fate of pyruvate in anaerobic respiration?
converted into lactate the exported out of cells
What is the function of kinases?
Add phosphate
Which steps are regulated in glycolysis?
Step 1, 3 and 9
Which enzymes regulate steps 1, 3 and 9 of glycolysis
1 - hexokinase
3 - phosphofructokinase 1
9 - Pyruvate kinase
What inhibits and promotes phosphofructokinase 1?
Inhibited by ATP, promoted by AMP
What molecule causes hexokinase to be bypassed in glycolysis?
glycogen
TRUE OR FALSE the PDH complex reversible
FALSE
What inhibits the PDH complex?
Products - Acetyl CoA and NADH
Nucleotides - GTP, AMP
Phosphorylation - inactivates
Pyruvate
Describe the kreb’s cycle
Bridge between glycolysis through to oxidative phosphorylation,
Where does the Kreb’s cycle occur?
mitochondrial matrix
What are the two phases of the Kreb’s cycle?
Regeneration and oxidation
What type of respiration is the Kreb’s cycle essential for?
Aerobic
How many times does the Krebs cycle operate per molecule of glucose?
twice
What happens in the oxidation phase?
NAD+ and FAD+ are reduced into NADH and CO2 and FADH2
What steps of oxidative phosphorylation are controlled?
Acetyl CoA -> Citrate
Isocitrate -> a-ketoglutarate
a-ketoglutarate -> Succinyl CoA
What are the suppliers of the Krebs cycle?
Fats, Polysaccharides and proteins
What is the production of the Krebs cycle per ONE glucose molecule?
4CO2, 2ATP, 2FADH2, and 6NADH
What is the production per a SINGLE cycle of the krebs cycle
2CO2, 1ATP, 1FADH2 and 3NADH
What is the function of the PDH complex?
Convert pyruvate into Acetyl CoA
Products from the breakdown of amino acids also feed into the Krebs cycle TRUE or FALSE
TRUE
What is produced by the Electron Transport Chain?
h2O, ATP
What is the NET yield from PDH complex?
2NADH
What is the NET yield from Krebs cycle?
6NADH, 2FADH2 and 2GTP
What is the total yield of ATP from glycolysis, krebs and PDH combined?
36 ATP
How many complexes are in the electron transport chain?
4
What drives the production of water in the ETC
giving up of electrons from cytochrome C
What is the function of the ETC
Establish a proton gradient across the inner mitochondrial membrane to drive ATP synthase to produce ATP
What is the final reaction of of ETC?
O + 2H+ –> H2O
Where does the ETC occur?
Across the inner mitochondrial membrane
TRUE or FALSE the ETC requires oxygen
TRUE
What are the electron carriers of reaction 1 in the ETC?
NAD and FAD
What are the electron carriers of reaction 2 in the ETC?
Ubiquinone
Describe ubiquinone
Fat soluble, co-enzyme Q, accepts one or two electrons
What are the electron carriers of reaction 3 in the ETC?
Cytochromes
Which type/s of cytochrome is soluble
type c
What are the electron carriers of reaction 4 of the ETC?
iron-sulphur proteins
What reaction in the ETC causes the oxidation of succinate into fumarate?
Reaction 2
Describe how ATP-synthase produces ATP
protons cause the subunit to rotate by 1/3 this causes a conformational change in the beta subunit
How many protons are required to aid ATP- synthase make 1ATP
3
What are the inhibitors of the Krebs cycle?
Cyanide, Azide, Carbon monoxide and uncoupling agents
What is the effect of uncoupling agents on the Krebs cycle
dissipation of the proton gradient
What complex do cyanide, azide and carbon monoxide act on
Complex IV
What genetic disorder is caused by mutations in ETC?
Leigh syndrome
What is the main site of energy production?
Mitochondrial matrix
TRUE or FALSE - glucose can be made from Acetyl CoA
FALSE
Which tissues exhibit metabolic specialisation?
Brain, liver, adipose tissue, and skeletal muscle
What is the function of ketone bodies?
Alternative source of energy during short term fasting
What is the major fuel for muscle metabolism?
Glucose, fatty acids and ketone bodies
What is the source of energy for heavy activity of muscle metabolism?
Muscle glycogen
Where is the site of glucose production during starvation?
kidney
What happens in the liver when blood glucose levels drop?
Liver signals to breakdown glycogen, reduces glycolysis and increases gluconeogenseis
Describe Type 1 diabetes mellitus
immune system destroys pancreatic beta cells
What happens in type 1 diabetes mellitus
insulin production stops, blood glucose regulation is disrupted
Describe type 2 diabetes mellitus
insulin resistance, pancreas loses its ability to produce insulin
What are diabetes mellitus diseases characterised by?
high levels of blood glucose
How do you treat diabetes mellitus?
insulin injections
What is inhibited in type 1 diabetes mellitus?
glycolysis
What state is the liver stuck in in type 1 diabetes mellitus
ketogenic and gluconeogenic
