BioChem: Glycolysis
Terms
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- What is metabolism?
- -the entire netweork of chemical reactions carried out by living cells
- What are metabolites?
- -small molecule intermediates in the degradation and synthesis of polymers
- What are catabolic reactions?
- -degrade molecules to create smaller molecules and energy
- What are anabolic reactions?
- -synthsize molecules for cell maintenance, growth, and reproduction
- What are the four major groups of biomolecules that undergo metabolism?
-
-carbohydrates
-lipids
-amino acids
-nucleotides - What is beneficial about multi-step pathways?
-
-permit control of energy input and output
-provide energy in smaller stepwise amounts (catabolic)
-each enzyme catalyzes only one step in pathway
-control points exist
-smaller amounts of energy are available for use of cell rather than one large energy source - What are the three major nutrients consumed by mamals and can be used as metabolic fuels and what are they used for?
-
-carbohydrates (energy)
-proteins (AA for protein synthesis and some energy)
-fats (triacylglycerides for energy and lipids for membrane synthesis) - What does compartmentation provide?
-
-separate pools of metabolites within a cell
-simultaneous operation of opposing metabolic paths
-high local concentrations of metabolites
-coordinated regulation of enzymes - What is an example of compartmentation in metabolism?
-
-fatty acid synthesis enzymes (cytosol)
-fatty acid breakdown enzymes (mitochondria) - What is the Golgi apparatus used for in metabolic processes?
- -sorting and secreation of some proteins
- What does the ER do in metabolic processing?
- -delivers proteins and synthesizes lipids for membranes
- What does the Nucleus do in metabolic processing?
- -nucleic acid synthesis
- What does the Nuclear and Plasm membranes do in metabolic processing?
- -nothing
- What does cytosol do in metabolic processing?
-
-fatty acid synthsis
-glycolysis
-most gluconeogensis reactions
-pentose phosphate pathway - What does teh mitochondrion do in metabolic processing?
-
-citric acid cycle
-oxidative phosphorylation
-fatty acid breakdown - What is the major source of energy for living cells and what is the major form of stored carbs in animals?
-
-starch
-glycogen - List the enzymes that catalyze each step of glycolysis starting with step 1.
-
-hexokinase
-phosphoglucose isomerase
-phosphofructokinase-1
-aldolase
-triose phosphate isomerase
-glyceraldehyde 3-phosphate dehydrogenase
-phosphoglycerate kinase
-phosphoglycerate mutase
-enolase
-pyruvate kinase - Overall, what are the products of glycolysis?
-
-2 pyruvate
-2 NADH
-2 ATP - For red blood cells, what is the free energy during glucose phosphorylation?
- - (-33.9kJ/mol)
- Which step of glycolysis is the reverse of an aldol condensation?
- -reaction 4
- After which reaction in glycolysis do two pathways begin in replicate?
- -Reaction 5
- What reactions in Glycolysis are Yeild Phase reactions (gives energy)?
- -Reactions 7 and 10
- Where is the site of action of arsenate?
- -Glyceraldehyde-3-phosphate DH
- Step 1-5, what are the descriptions of each reaction?
-
1)Phosphorylation of glucose by hexokinase
2)Conversion of Glucose-6-Phosphate to Fructose-6-Phosphate
3)Phosphorylation of Fructose-6-Phosphate
4)Catalyzation by Aldolase
5)Interconversion of triose phosphates - Step 6-10, what are teh descriptions of each reaction?
-
-Oxidation of Glyceraldehyde-3-Phosphate
-First ATP Synthesis
-Interconversion of 3-phosphoglycerate and 2-phosphoglycerate
-Dehydration of 2-phosphoglycerate
-Second ATP production - What is the primary sugar used for energy in the cell?
- -glucose
- What are some other carbohydrates that can yield energy in glycolysis?
-
-mannose
-galactose
-glycerol - Where are the most amounts of glycogen found?
- -liver and muscle which can mobilize stored carbs using hormones and muscle contraction
- What is the difference between glycogen and starch?
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-glycogen has 9% branching and a molecular weight of 5,000,000
-starch has 4% branching and a mol weight between 50,000-1,000,000 -
In the liver, kidney, and intestine what hormone supplies blood glucose?
How is this done? -
-Glucose-1-phosphate phosphatase
-G-1-P can be converted to G-6-P - How are glycogen stores mobilized?
- -glucagon and epinephrine
-
What are the two forms of glycogen phosphorlyase and where are they found?
How do you get the inactive form to activate? -
-active form Phosphorylase a
-inactive form Phosphorylase b
+treat liver slices with epinephrine -
What affect does epinephrine treatment (on Phosphorylase b) have on membrane fraction?
How about cytoplasm? -
-removes hormone
-activates hormone - What causes cAMP synthesis?
- -epinephrine
- How does epinephrine cause cAMP snythesis?
-
-hormone binds to membrane receptor
-this causes GDP bound to G-protein to be replaced with DTP
-GTP bound to alpha subunit if G-protein diffuces to Adenylate Cyclase in the membrane
-GTP-bound G-protein activates Adenylate Cyclase - What does cAMP do?
- -activates phosphorylase kinase (by activating Protein Kinase 1)
- What does Phosphorylase kinase activate?
- -glycogen phosphorylase
- Overall, how does hormone control work starting with epinephrine?
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-epinephrine activates adenylate cyclase to make cAMP
-cAMP activates Protein Kinase 1
-Protein Kinase 1 acrivates Phosphorylase Kinase which activates Glycogen Phosphorylase - What does Glycogen Synthase use to make glycogen?
- -UDP-Glucose
- What does Glycogen Synthase occur as?
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-Dependent
-Independent - When is Glycogen Synthase D dependent of Glucose-6-Phosphate?
- -when it's phosphorylated
- What are some glycogen storing diseases and what are they lacking?
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-Cori's Disease: debranching enzyme
-Andersen's Disease: branching enzyme
-McArdle's disease: muscle glycogen phosphorylase - What are three glycolysis syndromes?
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-fructose intolerance
-pyrucate kinase deficiency
-malignant hyperthermia