Respiration Flashcards
What is aerobic respiration?
- The complete breakdown of glucose to form carbon dioxide and lots of ATP- Requires oxygen- Slow- More ATP produced per molecule of glucose than in anaeobic
What is anaerobic respiration?
- The incomplete breakdown of glucose to form harmful products such as lactic acid in animals and bacteria and ethanol in plants and yeast - Doesn’t need oxygen- Fast
Where does glycolysis take place?
In the cytoplasm
Is glycolysis aerobic or anaerobic?
Anaerobic
What are the net products of glycolysis?
- 2 ATP- 2 NADP- 2 Pyruvate
What happens to glucose in glycolysis?
It is phosphorylated by adding a phosphate from ATP
What is glucose phosphorylated to in glycolysis?
Glucose phosphate
What happens to glucose phosphorylate in glycolysis?
It is phosphorylated by adding a phosphate from ATP
What is glucose phosphate phosphorylated to in glycolysis?
Hexose Bisphosphate
What happens to hexose bisphosphate in glycolysis?
It splits (due to its reactivity) into two triose phosphate molecules
What happens to each triose phosphate molecule in glycolysis?
They are oxidised to form pyruvate
When are the products of glycolysis produced?
During the oxidation of triose phosphate to pyruvate
What is the organic product of glycolysis?
Pyruvate
Where does the link reaction take place?
Inside the matrix of the mitochondria
What are the products of the link reaction per reaction?
1 CO2, 1 NADH
What are the products of the link reaction per glucose?
2 CO2, 2NADH
What is dehydrogenation?
Loss of a hydrogen atom or ion
What is decarboxylation?
Loss of a carbon atom
What happens to pyruvate in the link reaction?
It is dehydrogenated and decarboxylated to form acetate
What happens to the hydrogen removed from the pyruvate during the link reaction?
It reduces a molecule of NAD to NADH
What happens to the carbon removed from the pyruvate during the link reaction?
It combines with oxygen to form carbon dioxide which is a product of respiration
What happens to the acetate obtained from pyruvate?
It combines with coenzyme A to form acetyl coenzyme A
Where does the krebs cycle take place?
In the matrix of a mitochondria
What happens do acetyl coenzyme a in the krebs cycle?
It joins a 4 carbon compound to form a 6 carbon compound
What happens to coenzyme A after acetate has been used to form a 6 carbon compound? (krebs)
It is recycled back to the link reaction
What happens to the 6 carbon compound? (krebs)
It is decarboxylated and dehydrogenated to form a 5 carbon compound- Decarboxylation produces carbon dioxide as a waste product- Dehydrogenation reduces NAD to NADH
What happens to the 5 carbon compound? (krebs)
- Decarboxylation- Reduction (2NAD to 2NADH + FAD to FADH)- Substrate level phosphorylation
What is substate level phosphorylation?
Creation of ATP without ATP synthase, phosphate is added to ADP from another molecule
What happens to the 4 carbon compound after substate level phosphorylation?
It goes to the start of the cycle to combine with acettate from acetyl coenzyme A
How can lipids and proteins be respired aerobically?
They are broken down into acetyl coenzyme A to enter the krebs cycle
What are the products of the krebs cycle per cycle?
- 3 x NADH- 1 x ATP - 1 x FADH- 2 x CO2
What is the first step in oxidative phosphorylation?
NADH and FADH are oxidised to release electrons and protons
What happens once electrons are released from coenzymes? (oxidative phosphorylation)
Electrons flow along an electron transport chain in a series of redox reactions
What happens to the energy released from electrons passing down the electron transport chain? (oxidative phosphorylation)
Electrons release energy which is used to join ADP and Pi
What is the final electron acceptor? (aerobic respiration)
Oxygen, it combines with electrons and protons to form water
Which stage of respiration produces the most ATP in aerobic respiration?
Oxidative phosphorylation
Where does glycolysis take place?
In the cytoplasm
Which type of respiration is the more efficient producer of ATP?
Aerobic respiration
What happens in anaerobic respiration?
- Glycolysis takes place and then pyruvate is further used to oxidise NADH to NAD which is then re used in glycolysis
Why does anaerobic respiration happen?
NAD needs to be regenerated
What is produced in anaerobic respiration in mammals and bacteria?
Lactate (lactose fermentation)
What is produced in anaerobic respiration in yeasts and plants?
Ethanal which is then reduced to ethanol (alcoholic fermentation)
Does anaerobic respiration produce more or less ATP that aerobic?
Anaerobic respiration produces less ATP because lactate/ethanol aren’t fully respired (still have chemical energy)
What doesn’t anaerobic respiration have?
Oxygen as a final electron acceptor
What is a respiratory substrate?
Any biological molecule that can be respired to release energy
What are three respiratory substrates?
- Carbohydrates- Lipids- Proteins
Why does every cell respire?
Respiration is essential life because ATP is needed for all metabolic processes (e.g. active transport), cells also need to produce the minimum amount of ATP needed to maintain metabolism
Which respiratory substate has the most energy per gram?
Lipids > Proteins > Carbohydrates
Which respiratory substate is used last?
Protein is only respired when there’s no lipids or carbohydrates
What is the mitochondria?
The site of aerobic respiration in a eukaryote
What makes up a mitochondria?
- Mitochondrial DNA- Matrix- Cristae- Inner membrane- Outer membrane
What is the matrix of a mitochondria?
Site of the link reaction and the krebs cycle
What is the cristae of a mitochondria?
- A fold in the inner membrane of the mitochondria- Increases the surface area for oxidative phosphorylation
