IB BIO TOPIC : 8 CELL RESPIRATION Flashcards
What does oxidation involve ?
- Loss of electrons from an element
- Gaining oxygen
- Losing Hydrogen
What does reduction involve ?
- Gain in electrons
- Loss of oxygen
- gaining Hydrogen
What are the 3 main steps of Cell respiration ?
- Glycolysis
- Krebs Cycle
- Electron Transport Chain
What are the 4 steps within Glycolysis ?
- Phosphorylation
- Lysis
- Oxidation
- ATP formation
Describe the process of Glycolysis
- In the cytoplasm, one hexose (6 carbon) is converted into 2 three-carbons atom compounds (pyruvates) = GAIN of 2ATP and 2 NADH+ H+.
- In Phosphorylation, ATP loses 1 of its phosphates to the sugar to become ADP. This added phosphate makes sugar unstable and allows it to be broken down more easily.
- In Lysis, the 6 carbon molecule is split by enzymes into 2 three-carbon molecules of PGAL/G3P/TP. Each PGAL is then oxidised (Hydrogen ion removed and added to an ion carrier NAD+), which makes 2 molecules of NADH
What is the relationship between the structure of the mitochondrion and its function ?
- Mitochondria are organelles that are involved in aerobic respiration in the cell.
- On their inner membrane (cristae) and in their fluid matrix are enzymes and materials needed for all stages of aerobic respiration = which produces ATP
- The cristae are folded to create more surface are so as to create more space for the electron transport chain to occur.
- There is so small space between inner and outer membranes for accumulation of protons.
Explain what Link reaction is :
In aerobic respiration (in mitochondria in eukaryotes) ech pyruvate is decarboxylated (CO2 removed).
The remaining 2carbon molecules (acetyl group) reacts with reduced coenzyme A, and, at the same time, one NADH+H+ (proton) is formed.
What is the Krebs Cycle ?
Each acetyl group (CH3CO) formed in the link reaction yields : (1 turn of cycle) 2 CO2. 3 times NADH+ H+ 1 time FADH2 1 time ATP
What is the name and role of NADH + H+ ?
- Nicotinamide adenine dinucleotide dehydrogenase (NADH)
- Hydrogen-carrying coenzyme/electron donor.
- NADH oxidises into NAD and liberates H+ and highly energised electrons in the beginning of electron transport chain.
- Hydrogen-carrying coenzyme/electron donor.
What happens in the Electron Transport Chain ?
- Electrons from NADH and FAD2 which are donated are passed through an electron transport chain to oxygen
- Which then combines with hydrogen to form Water
- Multi step reduction-oxidation (redox) process that occurs on the mitochondrial inner membrane
What is the role of Oxygen ?
- O enters aerobic respiration in final phase (ETC)
- responsible for maintenance of hydrogen concentration gradient between spaces separated by inner mitochondrial membrane
- Gradient promotes functioning of ATP synthetase (enzyme) and thus the phosphorylation of ADP to form ATP
- O Binds to free hydrogens to form water = hydrogen consumption keeps the hydrogen gradient and the proton traffic through the ATP synthetase.
What does the entire aerobic respiration process have to intent ?
MAKE ATP SYNTHETASE WORK
ex. Humans need to breathe oxygen to maintain that hydrogen concentration gradient and keep ATP synthetase working.
What are the 5 main parts of a chloroplast ?
Double membrane Starch Grain Grana Thylakoid Stroma
What does the chloroplast membrane do ?
It is a double membrane regulating internal conditions
What is the role of Thylakoids in chloroplasts ?
- Site of light dependent reactions
- large surface area to maximise light absorption
- Small space inside thylakoids allows for protein accumulation.
- the interior is acidic (Ph=4) high proton concentration allowing for chemiosmotic gradient
