lecture 8 - cellular respiration Flashcards
Where does cellular respiration occur?
In the cytoplasm and mitochondria of Plant and Animal cells.
What do cells need energy from cellular respiration for? (4)
Mechanical work, making new materials, transport, maintain order
What is the overall equation for the breakdown of glucose in cellular respiration?
glucose + 6 oxygen -> 6 carbon dioxide + 6 water + energy
What is the chemical formula for glucose?
C6H12O6
What is the typical size of a mitochondrion?
1-10µm
How many mitochondria are in each cell? What is this dependent on?
1-1000. The energy demand of the cell.
What are the features of mitochondria structure?
Mitochondrial DNA, ribosomes, outer membrane, inner membrane (with folds - cristae), mitochondrial matrix
What are the three stages of cellular respiration?
Glycolysis, Pyruvate oxidation and the Citric Acid cycle, Oxidative phosphorylation.
Where does glycolysis occur?
In the cytoplasm/cytosol of the cell.
What is the process of glycolysis?
Glucose is broken down into pyruvate, generating 2 ATP, and high energy electrons which are transferred to the high energy electron carrier NAD+, making it into NADH. (2NADH are formed)
What is glucose converted to in glycolysis?
Pyruvate
How many carbons do pyruvate molecules have?
3
What is pyruvate converted into in the second stage of cellular respiration?
Acetyl CoA
What process forms 2 Acetyl CoA?
Pyruvate oxidation
What does pyruvate oxidation release/form?
2 Acetyl CoA, 2 Carbon dioxide, higher energy electrons in 2 NADH
What substance goes into the Citric Acid cycle?
Acetyl CoA
What does the Citric Acid cycle output (for 2 Acetyl CoA)?
6 NADH, 2 FADH2, 4 CO2, 2 ATP
What are the high energy electron carriers released from the citric acid cycle?
NADH and FADH2
What are the two parts of Stage 3 of cellular respiration?
Electrons transport & proton gradient, Chemiosmosis
How are high energy electrons moved to the inner mitochondrial membrane in Phase 3 of cellular respiration?
Via electron carriers (NADH and FADH2) that move through protein complexes (I to IV)
What causes protons to flow through the semi-permeable membrane in Stage 3 of cellular respiration?
The flow of electrons/electron carriers through protein complexes (i to iv) causes H+ to be pumped by proteins against its concentration gradient into the intermembrane space.
Why is there a gradient across the inner mitochondrial membrane?
H+ accumulate on the inter membrane space, creating a proton gradient.
What is the second phase of stage 3 of cellular respiration?
Chemiosmosis
What is chemiosmosis?
The inter mitochondrial membrane contains ATP synthase which synthesises ATP, by converting ADP.
What is the equation for the production of ATP in chemiosmosis?
ADP + Pi -> ATP
Why is ATP used to provide the cell with energy?
It provides a controlled release of energy, which can be harnessed in a useful way.
How is water produced in cellular respiration?
At the end of the electron transport chain of protein complexes, hydrogen ions combine with oxygen to form 6H2O
What is the relative pH of the inner mitochondrial space?
Low
