Lecture 3 Flashcards
Metabolic pathway
A particular sequence of connected reactions.
Metabolism
All chemical reactions taking place in an organism.
Enzyme
a protein that facilitates a specific chemical reaction.
How are metabolic pathways?
Metabolic pathways are interconnected (can go in multiple place not just the path deigned there), and aren’t especially layed out in an assembly line (like in drawing):
What is ATP?
(Adenosine TriPhosphate = 3 phosphate has more chemical energy): a high-energy molecule used to provide energy in cells.
What is ADP?
(Adenosine DiPhosphate = 2 phosphate): the lower-energy form of ATP.
How do you transform ATPP to ADP and vice versa?
To transform one into the other you have to use energy
atp to adp
release energy and that how it’s transported and transforms
adp to atp
need energy force to put the phosphate in adp and makes atp
and it’s the energy of reaction that fills energy to cells.
What are examples of high energy molecules?
NADH
FADH2
NADPH
Are high-energy molecules (carrying high-energy electrons).
What are examples of low energy molecules?
NAD+
FAD+
NADP+
Are the low energy forms of above molecules (without high-energy electrons).
Cellular respiration
C6H12O6 (glucose) + 6O2 –> 6CO2 + 6H2O + energy (in ATP and heat)
How does cellular respiration start?
Cellular respiration starts with glucose:
Describe the steps of cellualr respiration
Glucose goes through glycolysis (a cyclic metabolic pathway), it will turn glucose into pyruvate. Glycolysis releases energy that makes ATP (allows a phosphate to link to ADP) and NADH.
The pyruvate goes to another cyclic metabolic pathway, the citric acid cycle, that will create CO2.
Again this releases energy that will produce ATP, NADH+ and FADH2. Both cycles will create oxidative phosphorylation, it will take energy from both and generates more ATP.
What produces the ATP that is needed for energy in the cells?
Cellular respiration
Where does glycolisis happen in a prokaryote?
Glycolsis happens in the cytosol.
Where is oxidative phosphorylation found in the prokaryote?
This is found on the plasma membrane
Where does glycolisis happens in the eukaryote?
Glycolisis happens in the cytosol but the rest happens in the mitochondrion. More precisely the rest of the cycle happens in the matrix of the mitochondrion.
Where does oxidative phosphorylation happen in a eukaryote?
In the inner membrane of the mitochondrion
Glycolisis
a metabolic pathway that breaks down glucose into two molecules of pyruvate.
Energy released is used to change ADP to ATP and NAD+ to NADH.
First part of glycolisis
2 ATP into energy to go from C6 to 2x C3
Second part of glycolisis
Each G3P turns into pyruvate through a set of reactions. Creates 2 NADH and 4 ATP.
What is the glycolisis net total?
+2 NADH +2 ADP
what is Citric acid cycle (or Krebs)?
a cyclical metabolic pathway that breaks down pyruvate into 3 CO2.
Energy released is used to change ADP to ATP, NAD+ to NADH and FAD+ to FADH2.
for eukaryote it happens in the matrix
losing CO2 and NAD+ picks up energy to make NADH
From 1 pyruvate in the citric acid cycle it produces?
+4 NADH
+1 FADH2
+1 ATP
From one glucose molecule what is produced in the citric acid cycle?
From one glucose molecule you get 2 pyruvate therefore you get: 8 NADH, 2 FADH, 2 ATP.
Oxidative phosphorylation
A chain of molecules uses energy from NADH and FADH2 to generate H+ (hydrogen ion) gradient.
What is the H+ gradient used for?
The H+ gradient is used to change ADP to ATP.
Electron transport chain (step 1)
electron dropped off at the protein and energy released by electron along the chain used to pull H+ across the membrane and electron continues along. All of this is done along the plasma membrane.
ATP synthase
(-ase is usually enzyme) is an enzyme AND a channel protein, it allows H+ to pass through (the flow makes the turbine turn). The flow of H+ releases energy (though hydrogen gradient), and the energy is used to link P to ADP to make ATP (released in the matrix afterwards).
In ATP synthase Each NADH => produce
2.5 ATP
In ATP synthase Each FADH2 =>
1.5 ATP
Glycolysis, each molecule of glucose produces
Metabolic pathway that breaks down glucose into 2 molecules of
pyruvate (happens in the cytosol)
Citric acid cycle is
A cyclical metabolic pathway that breaks down pyruvate into three
carbon dioxide molecules (pyruvate still has some energy in it at this point)
How many ATP can be produced for each glucose through cellular respiration?
Generally, you can get 32 ATP for each glucose through cellular respiration.
What does each pyruvate release during the citric acid cycle?
Should know that for each pyruvate there is the release of
o 4 NADH
o 1 FADH2
o 1 ATP
