Respiration Flashcards
Where does aerobic respiration take place?
Mitochondia
What are the 4 parts of the mitochondria?
Crista
Matrix
Inner membrane
Outer membrane
What is a co-enzyme?
Molecule that adds the function of an enzyme by transferring a chemical group from one molecule to another
What are co-enzymes involved in respiration?
NAD
FAD
Co-enzyme A
What are the 4 stages of respiration?
Glycolysis
Link reaction
Krebs cycle
Oxidative phosphorylation
Where does glycolysis take place?
In the cytoplasm
What are the two steps in glycolysis?
1) phosphorylation
2) oxidation
Outline glycolysis.
Glucose is phosphorylated by ATP which produces ADP and glucose phosphate
The glucose phosphate is phosphorylated again to by another ATP molecule to form hexose biphosphate
Hexose biphosphate splits into two molecules of triose phosphate
Triose phosphate is then oxidised, 2 ATP for each triose phosphate molecule is produced and so is 1 NADH for each to produce two molecules of pyruvate
Where does the NADH produced in glycolysis go?
Oxidative phosphorylation
Where does the pyruvate produced in glycolysis go?
Link reaction in the matrix
Where does the link reaction take place?
Matrix in mitochondria
Outline the link reaction.
The pyruvate is decarboxylated by pyruvate decarboxylase, losing a carbon in the form of carbon dioxide and then oxidised to form acetate
Acetate joins with co-enzyme A to form acetyl co-enzyme A
What are the products of the link reaction?
2 acetyl co-enzyme A
2 carbon dioxide
2 Reduced NAD
Where does the acetyl co-enzyme A go?
to the Krebs cycle
Where does the Krebs cycle take place
in the matrix
What does the Krebs cycle produce?
Coenzymes and ATP
where does the reduced NAD produced in the link reaction go?
Oxidative phosphorylation
Outline the Krebs cycle
The coenzyme A goes back to the link reaction and the 2 carbon acetate joins with 4 carbon oxaloacetate to form 6 carbon compound citrate.
Citrate is then decarboxylated and oxidised, turning NAD into NADH, to form a 5 carbon compound
This 5carbon compound is then decarboxylated again, dehydrogenation occurs, turning one molecule of FAD into FADH and 2 molecules of NAD into NADH. Also ATP is formed from ADP and Pi. This forms oxaloacetate which starts the cycle again
What is the point of glycolysis, link reaction and Krebs cycle?
To make NADH and FADH for oxidative phosphorylation
What two things oxidative phosphorylation include?
Electron transport chain
Chemiosmosis
What is the first stage in oxidative phosphorylation?
Hydrogen atoms are released from NADH and FADH as they are oxidised to NAD and FAD.
The hydrogen atoms split into H+ and e-
What is the second stage in oxidative phosphorylation?
The electrons move down the electron transport chain, losing energy at each carrier
What is the third stage of oxidative phosphorylation?
The energy is used by electron carriers to actively transport H+ ions from the matrix into the intermembrane space
What is the 4th stage of oxidative phosphorylation?
The concentration of H+ ions is now higher in the inter membrane space than the matrix so there is an electrochemical gradient
What is the 5th stage of oxidative phosphorylation?
Protons move down the electrochemical gradient through ATP synthase and drive the synthesis of ATP from ADP and Pi, known as chemiosmosis
What is the 6th stage of oxidative phosphorylation?
At the end of the chain in the matrix, the protons, electrons and oxygen from the blood combine to form water
What is oxygen known as in oxidative phosphorylation?
Final electron acceptor
How many ATP molecules are produced from each reduced NAD?
2.5
How many ATP molecules are produced for each reduced FAD?
1.5
How many ATP molecule are produced in glycolysis?
2
How many ATP molecules are produced in oxidative phosphorylation from the 2 NADH produced in glycolysis?
5
How many ATP molecules are produced in oxidative phosphorylation from the 2 NADH produced in the link reaction?
5
How many ATP molecules are produced in the Krebs cycle?
2
How many ATP molecules are produced in oxidative phosphorylation from the 6 NADH produced in the Krebs cycle?
15
How many ATP molecules are produced in oxidative phosphorylation from the 2 FADH produced in the Krebs cycle?
3
How many molecules of ATP are produced all together in respiration from one molecule of glucose?
32
Outline alcoholic fermentation.
Pyruvate is decarboxylated into ethanal and then reduced as NADH is turned into NAD to produce ethanol
Outline lactate fermentation.
Pyruvate is reduced into lactate
What are alcoholic fermentation and lactate fermentation examples of?
Anaerobic respiration
Where does alcoholic fermentation occur?
in plants and yeast
Where does lactate fermentation occur?
In animal cells and some bacteria
What is aerobic respiration?
Respiration with oxygen
What is anaerobic respiration?
Respiration without oxygen
What is the equation for respiration?
C6H12O6 + 6O2 -> 6CO2 + 6H2O
Suggest an advantage of some of the lactate being converted back to pyruvate in the muscles when they are well supplied with oxygen (1 mark)
The pyruvate can then be used in aerobic respiration
