respiration SLOP Flashcards
(46 cards)
State 5 processes that ATP is used in
Active transport, DNA replication, cell division, endocytosis and exocytosis, protein synthesis, movement of bacterial flagella, phosphorylation of glucose in glycolysis
Describe the structure of ATP
Ribose (pentose) sugar, 3 phosphate groups (phosphoester bond attaches ribose to first phosphate; phosphoanhydride attaches adjacent phosphates), adenine base
State the name of two processes used to produce ATP in aerobic respiration
Substrate-level phosphorylation and oxidative phosphorylation
State all the stages of aerobic respiration in which ATP is produced
Glycolysis, Krebs cycle, oxidative phosphorylation
Describe how energy is released from ATP
ATP is hydrolysed to ADP, releasing an inorganic phosphate molecule
State the location of glycolysis
Cytoplasm
Describe how glucose is phosphorylated in glycolysis
2 x ATP molecules are broken down and their phosphate groups added to glucose to form hexose bisphosphate
Describe what happens to hexose bisphosphate in glycolysis
It splits into 2 x triose phosphate molecules
Describe how pyruvate is produced in glycolysis from triose phosphate
TP oxidised and H atom added to NAD to produce NADH; 2 x Pi group removed from TP and added to 2 x ADP molecules to form 2 x ATP
State the yield of ATP, NADH and pyruvate in glycolysis per glucose molecule
4 x ATP produced (net 2); 2 x NADH; 2 x pyruvate
Describe the process by which ATP is produced in glycolysis
Substrate-level phosphorylation - enzyme with 2 active sites (pyruvate kinase) takes Pi off phosphorylated compound (TBP) and adds them directly to ADP to make ATP
Describe how pyruvate and NADH reach the mitochondrion
Mitochondrial shunt mechanism - actively transported into mitochondrion
glycolysis involves oxidation despite it being an anaerobic reaction
Hydrogen atoms are being removed from TBP
Describe how the inner mitochondrial membrane is adapted for oxidative phosphorylation
Folded into cristae to provide a larger SA for electron carriers, ATP synthase enzymes, NADH dehydrogenase enzymes
State 3 things found in the mitochondrial matrix
Mitochondrial DNA, 70s ribosomes, enzymes for link reaction and Krebs cycle
Explain how the proton gradient is maintained in the intermembrane space
Phospholipid bilayer impermeable to protons (charged particles); they must pass through a hydrophilic channel protein or be pumped by active transport through a carrier protein
Suggest why the synaptic knobs of neurones contain many mitochondria
They need to synthesise many molecules of neurotransmitter and export them, via exocytosis, into the synaptic cleft. The mitochondria supply the energy needed to do this.
How are mitochondria replicated?
Divide by binary fission
Which stages of respiration take place in the mitochondrial matrix?
Link reaction and Krebs cycle
In what ways is the structure of the mitochondrion similar to that of a chloroplast?
For example, has envelope; folded inner membrane to give large surface area; ATP synthase enzymes and proton channels; electron transport chains; matrix; both have prokaryote-type ribosomes; both have loops of DNA.
In what ways is the structure of the mitochondrion different from that of a chloroplast?
For example, chloroplasts have chlorophyll; coenzymes in chloroplasts are NADP, in mitochondria NAD and FAD; different enzymes; chloroplast usually a bit larger, but both in region of 2–10 μm
Define the terms decarboxylation and dehydrogenation
Decarboxylation - removal of a CO2 molecule; dehydrogenation - removal of H atom(s)
Describe what happens to pyruvate in the Link reaction
Pyruvate is decarboxylated and dehydrogenated by pyruvate decarboxylase enzyme –> this produces carbon dioxide, reduced NAD and acetate. The acetate (acetyl group) is added to coenzyme A to form Acetyl CoA.
State the yield of ATP, NADH, acetate and CO2 in the Link reaction per glucose molecules
0 ATP produced, 2 x NADH, 2 x CO2, 2 x acetate
