Biology 1 Chapter 9 (Lecture) Flashcards
Cellular Respiration
The catabolic pathway (releases energy by breaking down complex molecules to simpler compounds.) of aerobic and anaerobic respiration which break down Organic Molecules for the production of ATP. (HARVESTING CHEMICAL ENERGY)
Living cells require…
Energy from outside sources.
Energy flows into an ecosystem as…
Sunlight and leaves as Heat
Photosynthesis generates…
Oxygen and Organic Molecules which are used in cellular respiration.
Cells use chemical energy to generate…
ATP which powers work.
The breakdown of organic molecules is…
Respiration and Exergonic
Fermentation
(Anaerobic)
Is a partial degradation of sugars that occurs WITHOUT oxygen.
Aerobic Respiration
Consumes organic molecules and oxygen and yields ATP. This is the most prevalent and most efficient respiration.
Anaerobic respiration is similar but does not require…
Oxygen
CHO, Fats, and proteins are all consumed as
Fuel
The breakdown of glucoes is:
- Catabolic
- Has a negative DELTA G (also spontaneous and exergonic)
Oxidation-Reduction Reactions
Chemical reactions that transfer e- between reactants. (Redox Reactions)
Oxidation
A substance loses an electron and is oxidized.
Reduction
The substance gains an electron or is reduced (the amount of positive charge is reduced)
The electron donor
Reducing Agent
Electron Receptor
Oxidizing Agent
During cellular respiration the fuel is…
Oxidized and the oxygen is reduced.
During cellular respiration, most electrons travel the following “downhill route”:
From NADPH to NADH to the electron transport chain to oxygen.
Respiration is the cumulative function of 3 metabolic stages:
- Glycolysis “sugar splitting”
- Citric Acid Cycle
- Oxidative Phosphorylation
Glycolysis (# of ATP)
2 ATP
Citric Acid Cycle (# of ATP)
2 ATP
Oxidative Phosphorylation (# of ATP)
32-34 ATP
Total ATP per Glucose
36-38 ATP
Obligate Anaerobes
Carry out furmentation or anaerobic respiration & cannot survive in the presence of oxygen.
Facilitative Anaerobes?
They can survive using either fermentation of cellular respiration.
Cellular Respiration of Glucose (equation)
C6H12O6 + 6O2 → 6CO2 + 6H2O + 36-38 ATP
- DELTA G
Energy is released.
Exergonic
Catabolic
+ DELTA G
Energy used.
Endergonic
Anabolic
Glycolysis
- From glucose (6C) to 2 pyruvic acids (3C)
- Located in the cytoplasm/cytosol
- Uses 2 ATP to start the breakdown of one glucose
- 2 NAD’s are reduced to 2 NADH’s
- Net of 2 ATP’s produced
- 2 pyruvic acid molecules (3C) are produced
Acetyl CoA
- Connects the pyruvic acid of glycolysis to the citric acid cycle
- Pyruvic acid in the cytosol enters the mitochondria
- A CO2 is removed, and diffuses out of the cell
- A NAD is reduced to NADH
- A 2 carbon molecule of Acetyl CoA enters the citric acid cycle.
Citric Acid Cycle
- One cycle for each pyruvic acid
- Located in the matrix of the mitochondria
- Breaks up the 2 carbon Acetyl CoA into 2 CO2
- (3)NAD and (1)FAD remove H electron pair for the “ETS”
- 1 Substrate level ATP produced in each cycle = 2 ATP net
Oxidative Phosphorylation
- ATP Formation
- Uses energy just produced to bond a P to ADP in the matrix fluid of the mitochondria
- Two H electrons from the “ETS” + two H protons from chemiosmosis + one oxygen in the matrix fluid = H2O.