Biochemistry final content chapters 12,13,10, 16, and all previous info Flashcards
Glycolysis Overview- Reaction 1
Hexokinase- and is the first ATP investment
What prevents Glucose escaping from cells
A nucleophilic substitution
What has a low km for isoforms I, II, and III?
Broad Substrate specifically (fructose, mannose)
High Km for Hexokinase IV
liver enzymes also called Glucokinase
What contributes towards the role of the liver as “glucostat”?
Hexokinase IV, allowing the liver to adjust its rate of glucose utilization in response to varying blood glucose levels.
Which reaction within Glucose sets the state for a symmetric aldol cleavage?
Reaction 4
What is the second ATP investment?
Phosphofructokinase
What is a major control point for glycolysis?
PFK: which is an allosteric enzyme
Reaction 4-Fructose-1,6-biphosphate aldolase
cleavage to two triose phosphates
Under intracellular conditions, what is delta G?
Delta G is negative so that the reverse reaction proceeds as written into vivo. It is a reverse reaction of carbonyl condensation.
Reaction 6 has two roles
- Oxidation of the GAP creates 1 molecule of NADH
2. Creates a high energy 1,3 BPG
What does GADPH do?
conserves the energy of oxidation by coupling an exergonic reaction to an endergonic reaction. An energonic reaction is coupled to an exergonic reaction. It is coupled via formation of a thioester intermediate by enzyme.
Which two reactions is the energy of oxidation of an aldehyde to a carboxylic acid conserved in the form of ATP?
1,3-Bisphosphoglycerate(BPG), 3-Phosphoglycerate(3PG)
Reaction 8:Phosphoglycerate mutase
preparing to synthesize the next “high-energy” compoind
Reaction 9: Enolase-synthesis of the second “high energy” compound
This is an a,b elimination
Reaction 10: Pyruvate kinsase
the second substrate-level phosphorylation
Pk mechanism
Although the synthesis of ATP is an endergonic step, the overall reaction is exergonic because of the spontaneous tautomerization of the enolpyruvate to the more stable keto form (pyruvate)
Within Aerobic and anaerobic fates of glycolysis, what may NADH be oxidized to?
NAD+ in the citric acid cycle (aerobic fate)
NADH may also be
converted to NAD+ by transfer of electrons to an electron acceptor (anaerobic fate)
What are two common anaerobic fates?
Homolactic fermentation and alcoholic fermentation
Within anaerobic fates of pyruvate
NADH must be reoxidized to NAD+ for glycolysis to continue
What cannot keep up with the NADH produced by high rates of glycolysis
Oxidation in mitochondria
What lacks mitochondria?
Anaerobic organisms
Within lysozymes of lactate dehydrogenase
non-denaturing gel,;i.e. no SDS added
lysozymes catalyze the same chemical reaction but
have different sequences
What is a tetrametric protein?
LDH and it consists of M and subunits with small sequence differences
What are used diagnostically to monitor heart or muscle disease?
Lysozyme patterns, because disease affected cells will release cell content.
