Respiration Flashcards
What are the two types of respiration
Aerobic- involved oxygen and produces carbon dioxide, water and a lot of ATP. Anaerobic which is without oxygen and produces lactate ( in animals) or ethanol + carbon dioxide (in plants and fungi) and little ATP
Explain the process of glycolysis
- Glucose is phosphorylated to glucose phosphate, using 2ATP 2. Glucose phosphate is split into 2 triosephosphate molecules (3c) 3. 2TP is oxidised, forming 2NADH 4. Substrate level phosphorylation forms 4ATP and 2 pyruvate molecules are formed for every glucose oxidised
What are the products of glycolysis
2 molecules of ATP (as 4 were produced but 2 were used in phosphorylation so net increase is 2), 2 molecules of reduced NAD and 2 molecules of pyruvate
Describe the link reaction
(Pyruvate is actively transported from cytoplasm into mitochondrial matrix by carrier proteins on mitochondrial membrane) 1. Pyruvate (3c) loses a carbon atom (decarboxylation) to form a carbon dioxide molecule 3. 2c molecule is oxidised to acetate, losing H atoms (NAD reduced to NADH) 4. Acetate combined with co enzyme A to form acetyl co enzyme A
Where does the krebs cycle take place
In the matrix of mitochondria
Describe the krebs cycle
- 2c acetyl coenzyme A combines with 4c organic compound to produce a 6c molecule 2. 6c mol. Is oxidised, with H atoms transferred to from NADH and it loses a carbon as carbon dioxide, forming a 5c mol. 3. 5c mol is oxidised, with H atoms transferred to form NADH and loses a carbon as carbon dioxide to form a 4c mol. 4. 4c mol is further oxidised, forming NADH and FADH, ATP is also formed,the original 4c molecule is regenerated and the cycle continues
Describe the structure and some functions of ATP
A ribose, adenine and 3 phosphates. Functions are energy for active transport, the pi phosphorylates other compounds, anabolism in protein synthesis, secretion during exocytosis and muscle contraction
Describe the structure and function of mitochondria
Has an outer membrane, inner membrane that folds to from cristae, matrix which holds circular dna, 70s ribosomes and enzymes, also has atp synthase and h+ in inter membrane space. They are the sites of aerobic respiration, have short diffusion pathway as long and thin for 02, contains H+ and gradient is used to synthesis ATP via chemiosmosis, cristae folds to give large SA for atp synthase
Where does oxidative phosphorylation take place
On the cristae of mitochondria
Describe the process of oxidative phosphorylation/ the role of oxygen in aerobic respiration
- High energy electrons carried by reduced co enzymes NADH and FADH are passed to electron carriers 2. As electrons flow down the ETC, the loose energy which is transferred to pump H+ out of matrix into inter membrane space (active transport) 3. Electrons from ETC are transferred onto oxygen which combined with H+ to form water so 02 is final electron acceptor
How is ATP synthesised during oxidative phosphorylation/ describe chemiosmosis
- ATP synthase is located in the inner mitochondrial membrane. 2. There is a concentration of H+ in the inter membrane space due to the movement of electrons down the ETC. 3. H+ flow down their concentration gradient through ATP synthase protein and the energy is transferred to make ATP from ADP and Pi
Where does glycolysis take place
In the cytoplasm
Where does the link reaction take place
The matrix of mitochondria
How is ethanol produced in anaerobic respiration
Pyruvate molecules formed from glycolysis lose a molecule of co2 and accepts H atoms from NADH (also from glycolysis) to produce ethanol. Pyruvate+ NADH = ethanol + co2 + NAD
How is lactate produced from anaerobic respiration
Each pyruvate from glycolysis takes up a H atom from NADH (from glycolysis) to form lactate. Pyruvate + NADH = lactate +NAD
