Respiration Flashcards
What is the first step in respiration?
Glycolysis
What is the main idea of glycolysis?
It breaks down 1 glucose into 2 pyruvate
What are the three major phases of glycolysis?
Energy investment
Lysis
Energy harvesting
Describe the energy investment phase of glycolysis.
ATP phosphorylates glucose twice (2 reactions).
this requires the INVESTMENT of 2 ATP’s
What happens during lysis?
The phosphoryated glucose is broken into two 3C molecules (G3P) as the 6C is too weak.
Each G3P group has an inorganic phosphate group added(PO4-). Simultaneously, NAD+ is reduced to become NADH.
An enzyme removes the PO4- from the #C molecule and gives it to ADP, making ATP. This happens twice per 3C molecule (so 4x with glucose, making a ATP)
What is the electron carrier molecule used in Glycolysis?
NAD+
Which inorganic phosphate group is added to the G3P molecules in the energy harvesting stage?
PO4-
What is substrate level phosphorylation?
The direct transfer of a phosphate group to ADP from another phosphorylates compound)
What are the infolds of the mitochondrias inner membrane called?
Crisitae
Why do cristae exist?
To increase SA for oxidative phosphorylation, chemiosmosis etc.
What is the space inside the inner membrane of the mitochondria called?
Matrix
Where does the link rxn occur?
Matrix
Where does the krebs cycle occur?
Matrix
What is in the inner membrane?
The electron transport chain and ATP synthase
Why is the intermembrane area small?
So that the H+ build up quickly, creating the gradient for chemiosmosis quickly.
Describe the DNA of mitochondria
It is circular
naked
contains genes for DNA
Why is the outer membrane of the mitochondria important?
It helps create an ideal condition for aerobic respiration.
What type of ribosomes are in mitochondria?
70s ribosomes.
What features of Mitochondria
What is the endosymbiotic theory?
It hypothesises that eukaryotic cells are of origin from prokaryotic organisms.
What evidences of mitochondria support the endosymbiotic theory?
Mitochondria has its own DNA
Mitochondria can replicate
Same size as prokaryotic cells
70s ribosomes, like procaryotes
Double membrane- inner membrane would be that of a prokaryote)
What is the link reaction?
It makes the products of glycolysis usable for the krebs cycle. pyruvate becomes Acetyl CoA .
Explain how pyruvate becomes Acetyl CoA in the link reaction.
NAD is reduced to NADH
pyruvate is decarboxylized
(CO2 is taken away)
Coenzyme A is added
Acetyl CoA is formed
Explain steps in the krebs cycle.
CoA is removed. Acetyl
(2C) is combined with a 4C molecule.
It is carboxylized and NAD is reduced, this happens 2x
ADP is phosphorylated, ATP
FAD becomes FADH
NAD becomes NADH
in total, 3 NADH’s are formed
one FADH
2 CO2s are released
1 ATP
What happens after the krebs cycle?
The products from the krebs cycle enter the ETC.
NADH and FADH2 are full of energy and are passed between electron carrier molecules, releasing energy. This triggers the pumping of H+ ions into the inter-membrane space, quickly creating a proton gradient. The H+ follow their electromagnetic gradient and passively move through the enzyme ATP synthase, via chemiosmosis, triggering oxidative phosphorylation. oxygen is the final H+ receptor and binds with the hydrogens to form water. This reaction releases 32-34 ATP. When joined with he 2 ATP from glycolysis, up to 38 ATP is created.
Where does anaerobic respiration occur?
in the cytoplasm.
WHy is anaerobic respiration important?
Because it generated NAD which is needed for glycolysis.
What are the products of anaerobic respiration?
2 NAD+, CO2, lactic acid, ethanol
What are the products of aerobic respiration?
Water and CO2.
