Cellular Respiration Flashcards
What is ATP composed of?
adenine, ribose, 3 phosphates joined by high energy bonds
Define cell respiration
heterotrophs; converting organic compounds in the presence of oxygen to CO2; also creating ATP
ex. animals, fungi bacteria
Cell Respiration Chemical Reaction
C6H12O6+ 6O2–>6CO2+6H2O+ ATP
Difference between catabolic & anabolic reactions
Anabolic- building bigger molecules; absorbing energy
Catabolic- breaking down bigger molecules; releasing energy
The difference between oxidation vs. reduction
oxidation: gain of oxygen, loss of hydrogen &, electrons
Reduction: loss of oxygen, gain of hydrogen & electrons
What are the key OXIDIZED coenzymes in cell respiration?
NAD+
FADH
What are the key REDUCED coenzymes in cell respiration?
NADH
FADH2
List the 4 stages of cell respiration
Glycolysis
Pyruvate oxidation
citric acid/Krebs cycle
chemiosmosis/electron tranport
Name the two key enzymes in cell respiration
Dehydrogenase and Kinase
Define dehydrogenase
Enzymes that remove hydrogens from substrates
and add them to NAD+ or FAD reducing them to
NADH or FADH2
Define Kinase
Transfer phosphate from one molecule to
another. (Substrate to ADP) or (ATP to substrate)
Define the two types of phosphorylation
Substrate level phosphorylation
Oxidative phosphorylation
Define substrate level phosphorylation
An enzyme transfers a phosphate from a
substrate (a molecule) to ADP, yielding ATP:
ex: 1,3 Bisphosphate glycerate loses a
phosphate to ADP—–> ATP
Define Oxidative Phosphorylation
Energy from redox reactions in electron-
transport chain is used to make ATP.
define redox reactions
oxidation and reduction
Where does glycolysis take place?
the cytoplasm
Is glycolysis anaerobic or aerobic?
anaerobic- does not use oxygen in this step
What does glycolysis do?
Coverst 6 carbon glucose into 2 3 carbon pyruvaes. Uses 2 ATP to create more ATP
What are the beginning molecules of glycolysis?
1 glucose
2 ADP
2 NAD+
put in 2 AT
What are the ending molecules of glycolysis?
2 pyruvate each with 3 Carbon
2 net ATP (4 formed, but 2 used up initially)
and 2 NADH
What types of phosphorylation occur during glycolysis?
substrate level phosphorlation
Is pyruvate oxidation anaerobic or aerobic?
aerobic
Where does pyruvate oxidation take place?
In the matrix of the mitochondria
What occurs during pyruvate oxidation?
The two 3cpyruvate is converted into two Acetyl-CoA;
1. Pyruvate goes through a transport protein and CO2 is removed and it is oxidized.
2. The electrons go to NAD+ to form NADH.
3. Coenzyme attaches to the 2c acetyl group
What are the beginning molecules of Pyruvate Oxidation?
2 pyruvate
2 Coenzyme
2 NAD+
What are the ending molecules of Pyruvate Oxidation?
2 Acetyl CoA
2 CO2 molecule
2 NADH
What enzyme is involved in pyruvate oxidation?
Pyruvate Dehydrogenase
Where does Krebs cycle/ Citric Acid cycle take place?
inside the matrix of the mitochondria
Is the Krebs cycle/ Citric Acid cycle aerobic or anaerobic?
aerobic
What is the function of the Krebs cycle?
To make reduced Coenzymes; release CO2 and make small amount of ATP
What are the beginning molecules of the Krebs cycle?
2 Acetyl-CoA
6 NAD+
2 FADH
2 ADP
What are the ending molecules of the Krebs Cycle?
4 CO2
6 NADH
2 FADH2
2 ATP
How many times does the Krebs cycle turn to break down 1 Glucose?
1 glucose=2 pyruvates= CO2+ 2Acetlyl-COa
turns twice
How much ATP does each NADH produce?
2.5 or 3 ATP
How much ATP does FADH2 produce?
1.5 or 2 AT
What is the function of the outer membrane in cell respiration?
boundary b/w inner mitochondria & cytoplasm
What process of cell respiration occur in the inner membrane?
ETC
What is the function of intermembrane space in cell respiration?
hydrogen pumping
What is the function of cristae during cell respiration?
folds of inner membrane; increase SA
What is the function of the matrix in during cell respiration?
kreb cycle enzymes
What is the first step of ETC?
NADH and FADH2 (reduced coenzymes from the kreb cycle, pyruvate oxidation and glycolysis) enter the chain & dump the electrons in the chain
What happens to the energy level as electrons dumped by NADH and FADH2 passes through the electrons? What is the final electron acceptor? (2nd step)
Drops in energy, release energy, exergonic reaction
Oxygen
What happens to the electrons travelling through the proteins?
They go in the matrix and combine in the matrix to make H2O
What is the energy from the electrons moving down the chain going to? What type of reaction is this?
used to pump hydrogen ions actively across the membrane from the matrix, to the intermembrane space making that side ACIDIC (decreases the pH) and increases membrane potential creating the proton motive force
This is an coupled reaction because the energy from the exergonic reaction is used for an endergonic reaction
What does increased H+ concentration in the intermembrane space allow for?
the passage of chemiosmosis of H+ ions through ATP synthase back to the matrix side
What happens after H+ flow through ATP synthase?
the knob turns (of ATP synthase) allowing for the phosphorylation of ADP
In which complex does NADH donate their electrons and why?
the electrons are at a very high level thus it donates the electrons directly to complex 1, becoming NAD+ which can be used later during glycosis
In which complex does FADH2 donate their electrons and why?
Electrons are at a lower energy level thus it cannot transfer its electrons to complex II and donates them to complex II which does not pump proteins across the membrane
Define chemiosmosis
ATP synthesis powered by the flow of H+ back across the membrane
Define electron transport chain
electron transport and pumping of protons which creates a H+ gradient across the membrane
What does the proton movement power?
it provides a direct source for generating ATP
What is the relative pH of the martix compared to the intermembrane space due to movement of H+?
The intermembrane space has a lower pH acidic due to the higher H+ concentration in the intermembrane space
What is the difference between anaerobic respiration and aerobic respiration?
has electron transport chain but uses molecules other than oxygen as a final electron acceptor
- used by anaerobic prokaryotes
What is the similarity between respiration and fermentation>
Includes glycolysis but have different products
Define alcohol fermentation
in bacteria and yeast; pyruvate converted to ethanol; CO2 is released; NAD+ regenerated; ATP produced
define lactic acid fermentation
in muscle cells; pyruvate converted to lactate, NAD+ regenerated, ATP produced
What is the purpose of Oxidative Phosphorylation?
To generate large
amounts of ATP; to
regenerate oxidized
coenzymes; produce
water
What are the beginning molecules for Oxidative phosphorylation?
10 NADH,
2 FADH2,
O2,
ADP
What are the ending molecules for Oxidative phosphorylation?
32-38 ATP,
H2O,
10 NAD+,
2 FADH
