EXAM 3 Flashcards
How do we use cellular respiration in everyday life?
eating, digesting, absorbing nutrient molecules into our bloodstream, and delivering nutrient molecules to the cells
Through cellular respiration, our cells begin to extract some energy. What is important about this?
Our cells need ATP to maintain life, our metabolism is all chemical, a big focus is on breaking down glucose which is the main energy source during activity, and fatty acids and lipids are used during rest
What is gas exchange in cellular respiration?
Diffusion of CO2 and O2 across a cellular membrane barrier; diffusion of CO2 and O2 from air or water to body
What is circulation within cell respiration?
The bulk movement of a fluid throughout an animal body; it transports gas to/from body cells
What is cellular respiration?
Using O2 and producing CO2 to make ATP
What is ventilation in cellular respiration?
The bulk movement of an environmental fluid to the gas exchange surfaces of an animal; moving air or water to gas exchange organ
What is whole body respiration?
The rate of oxygen use and production of CO2 made by a whole animal
What are the stages of cellular respiration in order?
Glycolysis, pyruvate processing, citric acid cycle, electron transport and chemiosmosis
In ATP production, what is substrate level phosphorylation?
The transferring of a phosphate from a fuel source to ATP and it takes place in a glucose oxidation pathway
In ATP production, what is oxidative phosphorylation?
Energy is harnessed through the inner mitochondrial membrane to create ATP from protein complexes called ATP synthase and the electron transport chain
NADH transfers electrons in REDOX reactions
This is the reverse of photosynthesis; glucose is oxidized into CO2 and O2 is reduced into H20; cell respiration liberates the energy that glucose stores in its covalent bonds which will equal the amount of energy photosynthesis needs to make glucose and the cell will use this energy to make ATP; complete respiration of 1 molecule of glucose can provide enough energy to make 38 ATP
Redox: Oxidation
loss of electrons
Redox: Reduction
gaining of electrons
Within cell respiration…
Glucose is being oxidized
Glycolysis
The initial breakdown of glucose, the first set of reactions to occur within cell respiration, this is a series of 10 reactions, creates byproducts pyruvate (a 3 carbon sugar), ATP, NADH (energy carrying molecule that is similar to NADPH, Nicotinamide Adenine Diphosphate), occurs within the cytosol of the cell, does not require oxygen (anaerobic)
Steps of Glycolysis
- Glucose is phosphorylated by ATP to make Glucose 6-PO4 and ADP
- Glucose 6-PO4 is rearranged into an isomer Fructose 6-PO4
- Fructose 6-PO4 is then phosphorylated by ATP to make Fructose 1, 6 Biphosphate
4.Fructose 1,6 Diphosphate then breaks down into two molecules of G3P - Each G3P is then oxidized by NAD+ to make PGA-P and NADH
- Each PGA-P is converted into PGA by losing a PO4 to ADP and making an ATP
- Each PGA is converted into PEP (phosphoenolpyruvate)
- Each PEP donates a phosphate to ADP to make pyruvate and ATP
Summary of Glycolysis
Glucose is broken down into two pyruvates and a total of 4 ATP are made but two are used up meaning there is a net of 2 ATP, NADH (2) is produced and can be used up later in processes, its only about 2% efficient because it only produces 2 ATP from the partial breakdown of glucose
The fate of the pyruvate if oxygen is present
Pyruvate enters the mitochondrion to be broken down by aerobic respiration
The fate of pyruvate if oxygen is not present
Pyruvate remains in the cytosol and is fermented in anaerobic respiration
Aerobic respiration
requires oxygen and can produce very large amounts of ATP
Anaerobic respiration
without oxygen meaning its oxygen dependent, this produces only very small amounts of ATP, some bacteria may survive exclusively on anaerobic respiration
Pyruvate processing
Each pyruvate is processed to release one molecule of CO2 and the remaining two carbons are used to combine and form Acetyl-CoA, occurs in the mitchondrial matrix in eukaryotes, requires oxygen to occur
Steps of Pyruvate Processing
In the presence of O2 in the cytosol, pyruvate will be pumped into the mitochondria (each pyruvate has a potential to produce about 15 ATP), pyruvate is then oxidized by NAD+ and is decarboxylates (loses CO2) to become Acetyl, it then combines with an enzyme called Coenzyme A to become Acetyl-CoA
Products of Pyruvate Processing
Acetyl-CoA, CO2 (waste product), NADH per pyruvate