Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
31 Cards in this Set
- Front
- Back
What are four pathways of glucose utilization?
|
Structural polymers, storage, oxidation via glycolysis, oxidation via pentose phosphate pathway
|
|
How much ATP is produced by Glycolysis? in the electron transport chain? Maximum possible?
|
2 ATP in glycolysis, 28-30 ATP in electron transport, 30-32 total
|
|
Which ATP production is anaerobic? Aerobic?
|
Glycolysis - aerobic
Electron transport - anaerobic |
|
Where does glycolysis occur and what remains after glycolysis? What feeds into the krebs cycle, and where does the krebs cycle and electron transport occur?
|
Glycolysis occurs in the cytosol, and produces pyruvate.
Pyruvate feeds into the Krebs cycle, krebs cycle and electron transport occur in mitonchondria |
|
If oxygen is present what does pyruvate become? if anaerobic?
|
aerobic - acetyl-CoA
anaerobic - Lactate |
|
How much ATP does glycolysis requre? How much does it produce? What is the net yield?
|
Requires 2 ATP, produces 4ATP, yields 2 ATP
|
|
Other than ATP what does Glycolysis produce?
|
2 NADH
|
|
What is glucose broken down into during the first stage of glycolysis? and what do they become?
|
2 phosphoglyceraldehydes -> 2 pyruvates
|
|
What does Hexokinase do, and why is it important? Why is the product important?
|
it irreversibly phosphorylates (high neg. delta G for reaction) glucose which commits it to metabolism in the cell b/c glucose 6-P can not cross the cell membrane...
branch point for carbohydrate metabolism |
|
What are three irreversible reactions in glycolysis?
|
Glucose --hexokinase-> Glucose 6-P
Fructose 6-P --Phosphofrucokinase-> Fructose 1,6, bis -P Phosphoenolpyruvate --Pyruvate kinase--> Pyruvate |
|
What does Phosphofructokinase-1 do? What is it regulated by? In what pathway is it a rate limiting enzyme?
|
1- converts Fructose 6-P to Fructose 1,6-bis-P
2. Inhibited by ATP, activated by AMP 3. Glycolysis |
|
What converts Glucose to Glucose 6-P in the liver?
|
Glucokinase
|
|
Which of the 3 irreversible reactions produces ATP?
|
Production of pyruvate
|
|
What are the significant inputs and outputs of glycolysis?
|
Inputs 2-ATP
Output - 4 ATP - 2 NADH - 2 Pyruvate |
|
Which electron acceptor is necessary for glycolysis to continuse? How is the acceptor reoxidized?
|
NADH
Through shuttle systems |
|
In the absence of oxygen where does NADH deposit electrons? What does it produce?
|
Deposits on Pyruvate to make lactate
|
|
In the presence of oxygen what accepts electrons from NADH? and what does it do with them?
|
Glycerol 3-P and malate-aspartate shuttles. Uses them in electron transport
|
|
How many ATP is produced per NADH in Aerobic glycolysis?
|
3 ATP
|
|
Why are shuttles necessary in glycolysis?
|
Because NADH cannot pass across the inner mitochondrial membrane
|
|
Where is NAD located in the cell? Where is FAD located?
|
NAD - cytosol
FAD - mitochondria |
|
Which electron carrier system is more efficient? Which shuttle system involves FAD?
|
Malate shuttle 2.5 ATP
G-3-P shuttle - 1,5 ATP G-3-P |
|
In the glycerol 3-phosphate shuttle what accepts electrons from NADH? Which deposits electrons on what, which deposits electrons where?
Which enzyme catalyzes these steps? |
Glycerol 3-P accepts, deposits on FAD, which deposits in electron transport for a net gain of 1.5 ATP
glycerol 3-phosphate dehydrogenase |
|
Which enzyme works in the malate-aspartate shuttle? Which electron acceptor is involved?
How many ATP are produced? |
Malate dehydrogenase
NADH 2.5 |
|
What tissues rely on anaerobic metabolism?
|
RBCs, Skin, Brain, Skeletal muscle. Low ATP demand and few capillaries
|
|
Where is lactate reformed to glucose? How many Lactate molecules and ATP are required to reform glucose, and what is the process called? and what is the cycle called?
|
Liver
2 lactate + 6 ATP make a glucose Gluconeogenesis Cori Cycle |
|
What compounds does glycolysis produce that aid in biosynthesis? (4)
|
ribose-5 phosphate for nucleotides
Serine from 3-phophosglycerate Alanine from pyruvate Fatty acids from triglycerides |
|
What is a precursor for fatty acid biosynthesis, and in which tissues does it occur?
|
Pyruvate
Liver, fat |
|
What are three types of glycolytic regulation?
|
Hormones (glucagon and Insulin)
Allosteric regulation ATP, AMP Long Term - gene expression |
|
What allosteric factor is the key regulator of glycolysis?
|
ATP
|
|
What does AMPK stand for and what does it do in response to?
What about if active for a long time? |
Activated protein kinase
If ratio of AMP/ATP increases, it increases anabolic and catabolic ATP production, it regulates transcription |
|
What is hexokinase inhibited by?
|
Its product glucose 6-Phosphate
|