Cellular Respiration Flashcards
Cellular Respiration
Catabolic pathway that breaks down energy rich compounds to produce ATP
Steps in Metabolic Pathway
Glycolysis - cytoplasm/cytosol
Pyruvate Oxidation - mitochondrial matrix
Citric Acid Cycle - mitochondrial matrix
ETC and chemiosmosis (oxidative Phosphorylation) - inner mitochondria membrane
Glycolysis
oxidation of one 6-carbon glucose molecule - two 3-carbon pyruvate molecules
Soluble enzymes involved
2 phases of glycolysis
Initial phrase investment
energy payoff phrase
ETC - complex I
NADH dehydrogenase
ETC - complex II
FADH2 (succinate) dehydrogenase
ETC - complex III
cytochrome complex
ETC - complex IV
cytochrome oxidase
What is all the reactants and products doubled by in the citric acid cycle (net equation)?
2
What is completely oxidized (CO2)
Glucose, electron carriers NADH and FADH2 reach ETC
Chemiosmosis
process which ATP is synthesized using the energy of an electrochemical gradient and thee ATP synthase enzyme
Ubiquinone
also picks up H+ as it accepts electrons from complex]x I and II
Proton gradient
a difference in proton concentration across memebrance
electrical potential
An electric potential is the amount of work needed to move a unit of charge from a reference point to a specific point inside the field without producing an acceleration.
2 principle components of ATP synthase
Basal portion: intergal membrane proteins
- forms a channel for H+ ions pass freely via. proton motive force
head portion: extends into matrix
Uncoupling ETC and chemiosmosis
released as thermal energy
H+ rush back over membrane through uncoupling proteins
Example of ETC and chemiosmosis uncoupling
- Inner mitochondria membrane of brown adipose fat tissue
- protein channels take H+ back into matrix realizing thermal energy
In general how may ATP is getting multiplied Theoretically
NADH oxidized = 3 ATP
FADH2 oxidized = 2 ATP
How many ATP is produced Theoretically in Cellular respiration
38 ATP
In general how may ATP is getting multiplied Actually
NADH = 2.5 ATP FADH2 = 1.5 ATP
Creatine Phosphate
acts as ATP storage
Can be easily released for sudden ATP energy bursts or stored if no activity
Allosteric Regulation
ATP regulated to meet cellular energy requirements
- supply and demand
Example of Regulating Cellular respiration
Phosphofructokinase
- regulated at irreversible steps
- in glycolysis this can be inhibited or activited
What is beta-oxidation
sequential removal of acetyl groups from the fatty acid
How is an acetyl group broken down to CO2 and H2O
acetyl group are linked to CoA to make acetyl-CoA
acetyl-CoA enters the Krebs cycle and is broken down to CO2 and H2O
Protein Catabolism
Proteins are hydrolyzed to amino acids where some are used to makes cells own protein
Deamination
Removal of an amino group
Protein catabolism - amino acids depicts what type of substrate is produced
Alanine - pyruvate
Leucine - acetyl-CoA
Proline - a-ketoglutarate
phenylalanine - fumarate
When do organisms use Anaerobic Pathways
in poor oxygen enviro. ex. wet enviro, human digestive tract
two methods of Fermentation in eukaryotes
- ethanol fermentation
- Lactic Acid fermentation
Ethanol fermination
2 pyruvates are decarboxylated and forms 2 acetalaldedydes
What is waste products in Ethanol fermentation
CO2 and ethanol
Example of organism that carry out Ethanol fermentation
yeast
Uses of ethanol/ alcohol fermentation
Humans to make breads, pastries, beers, wines
Accumulation of ethanol in animals can cause death
Lactate fermentation
Glucose undergoes glycolysis to produce 2 pyruvates, 2NADH + 2H+ and 2 ATP net
2 pyruvates are reduced by 2NADH from glycolysis forming 2 lactates and 2 NAD+
Uses of Lactate fermentation
during exercise, muscles respire faster then the body can supply oxygen
What reaction is reversible? Why?
Lactate Fermentation
- when exercises cease, oxygen is present
- Lactate is shuttled to liver to be oxidized
- pyruvate and NADH are replenished
Why do pyruvates go in to mitochondria during Lactate Fermentation?
where undergoes aerobic cellular respiration
Substrate - Level phosphorylation
the formation of ATP by the direct transfer of a phosphate group from a substate to ADP
Oxidative phosphorylation
a process that forms ATP using energy transferred indirectly from a series of redox reactions
Glycolysis
series of reactions in which a glucose molecule is broken into two pyruvate molecules and energy is released
Pyruvate oxidation
reaction which pyruvate is oxidized by NAD+, CO2 is removed, forming an acetyl group and releasing NADH
citric acid cycle
cyclic series of reactions that transfer energy from organic molecules to ATP, and FADH2 and releases CO2
