BSI Lecture 31 Glycolysis and Lactic Acidosis Flashcards
What cellular process uses the most ATP?
- Protein synthesis 27%
- Na+/K+ ATPase 24%
- Gluconeogenesis 9%
- Ca2+ ATPase 6%
- Myosin ATPase 5%
- Ureagenesis 3%
________ refers to all chemical reactions occurring in the body (usually ordered in metabolic pathways).
Metabolism
_______ reactions release energy stored in organic molecules.
Catabolic
_______ reaction refers to catabolic reactions.
Exergonic
_______ reactions are synthesis reactions that consume energy
Anabolic
______ reactions refers to Anabolic reactions.
Endergonic
If “foodstuff” was oxidized in one reaction, what would happen to the energy?
It would be lost as heat and no energy would be stored
T or F? If “foodstuff” is oxidized in a stepwise manner, the free energy released can be stored in ATP.
True
T or F? Stepwise manner stores energy in ATP, ATP is then used for exergonic reactions.
False, used for endergonic reactions
This process is an incomplete oxidation of sugar.
Glycolysis
Energy comes from the breaking of _______ _______
Chemical bonds
In glycolysis, 1 glucose will turn into how many pyruvates?
2
Using oxygen, _______ can then enter the mitochondria for further oxidation.
Pyruvate
_______ produces immediate energy.
Glycolysis
______ is limiting in its abiity to continuously meet demands of cell.
Glycolysis
Where does glycolysis occur in cell?
Cytosol
What is the net ATP produced in glycolysis?
2
Glycolysis: Glucose is phosphorylated by what enzyme.
Hexokinase (Glucokinase if in the liver)
In the liver, the enzyme that phosphorylate glucose is called ______
Glucokinase
Glucose-6-phosphate is turned into what by Glucose-6-phosphate isomerase?
Fructose-6-phosphate
Fructose-6-phosphate is phosphorylated by what enzyme?
Phosphofructokinase (PFK)
After PFK has phosphorylated, what is the product?
Fructose-1,6-bisphosphate
How many carbons does fructose have?
6
Glycolysis: The fructose molecule is split into 2 molecules by what enzyme.
Aldolase
Glycolysis: Two molecules are produced from fructose splitting, what are they?
Glyceraldehyde-3-phosphate and dihydroxyacetone phosphate
Dihydroxyacetone phosphate is isomerized into a second molecule of glyceraldehyde-3-phosphate by what enzyme?
Triosephosphate isomerase
Glyceraldehyde-3-phosphate is oxidized and then phosphorylated by _________`
Glyceraldehyde-3-phosphate dehydrogenase
T or F? Glyceraldehyde-3-phosphate is phosphorylated into 1,2-biphosphoglycerate.
False, 1,3-diphosphoglycerate
What else is produced after Glyceraldehyde-3-phosphate is phosphorylated?
NADH + H+
Glyceraldehyde-3-phosphate is phosphorylated by what enzyme?
Glyceraldehyde-3-phosphate dehydrogenase
After phosphoglycerate kinase phosphorylates, what are the products made?
3-phosphoglycerate and ATP
Where does the phosphate come from when 3-Phophoglycerate + ATP is produced?
1,3 biphosphoglycerate donates a phosphate to ADP
Phosphoglycerate mutase rearranges 3-phosphoglycerate into ____________
2-phosphoglycerate
Enolase removes H20 from 2-phosphoglyerate to produce _____.
phosphoenolpyruvate
Pyruvate and ATP are produced after _____________ kinase removes a phosphate from _______ to phosphorylate ATP.
Pyruvate; phosphoenolpyruvate
In the Glycolytic pathway, which 2 steps utilizes ATP?
- When hexokinase phosphorylates glucose.
2. When phosphofructokinase phosphorylates fructose 6-phosphate.
In the Glycolytic pathway, which 2 steps is ATP created?
- When phosphoglycerate kinase phosphorylates ATP by removing a phosphate from 1,3diphosphoglycerate.
- When pyruvate kinase phosphorylates ATP by removing phosphate from phosphoenolpyruvate.
In the Glycolytic pathway, which step does 2 NAD+ and 2 phosphate come into play?
When glyceraldehyde 3-phosphate dehydrogenase phosphorylates glyceraldehyde 3-phosphate.
What does NAD+ do to glyceraldehyde 3-phosphate?
Strips electrons and transport it to the ETC
T or F? Pyruvate can be oxidized into lactate by lactate dehydrogenase.
False, reduced.
Oxidation is the _____ of electrons.
Reduction is the _____ of electrons.
Oxidation is the \_\_\_\_\_ of electrons. Reduction is the \_\_\_\_\_ of electrons. Loss; Gain (OIL RIG Oxidation Is Loss Reduction Is Gain)
Lactate dehydrogenase reduces pyruvate+NADH+H into _____ + _____.
lactate + NAD+
Anaerobic glycolysis: ___ glucose —> ___ pyruvate —> ___ lactate (nets ___ ATP) [fill in with numbers]
1;2;2;2
T or F? Anaerobic glycolysis is complete oxidation of glucose
False, incomplete
Anaerobic glycolysis occurs if _____ NOT available.
oxygen
T or F? Pyruvate enters the nucleus for further oxidation only if oxygen is available.
False, mitochondria
What is the purpose of reducing pyruvate to lactate during anaerobic conditions?
Important because NADH needs to recycled to NAD+ to grab electrons
What can happen to the build up of lactate?
- Other cells/tissues that are better oxygenated can take it up and use it for energy.
- Liver can take it up and use it for gluconeogenesis.
3 Can be eliminated by kidneys
A drop in pH resulting from condition where the production of H+ exceeds the removal of H+ accompanied by a build-up of lactate in the blood is called ______ _____
Lactic acidosis
Regulation of glycolysis: ____ must be maintained within limits.
ATP
What are the regulation of glycolysis?
- Rate limiting enzymes
- Things that stimulate glycolysis: ADP & Pi (low energy status), inisulin, epinephrine.
- Things that inhibits glycolysis: ATP (high energy status) and glucagon.
T or F Glucagon inhibits glycolysis only in the liver; glucagon has no effect in other tissues.
True
What are the rate limiting enzymes?
- Hexokinase
- PFK
- Pyruvate kinase
High blood glucose levels, among other things, stimulate secretion of _____ from pancreatic B-cells.
Insulin
T or F? Insulin stimulates uptake of blood glucose by various tissues and stimulates catabolic reactions.
False, anabolic
T or F? Insulin inhibits catabolic reactions.
True
T or F? The brain does not need insulin to take up glucose.
True
Low blood glucose levels, stimulate secretion of ______ from pancreatic alpha-cells.
Glucagon
Glucagon stimulates ______ reactions and inhibits ____ reactions.
catabolic; anabolic
______ leads to the accumulation of lactate.
hypoxia