respiration Flashcards
what are the four stages of aerobic respiration & where do they occur?
1) glycolysis → cytoplasm
2) link reaction → matrix
3) kerbs cycle → matrix
4) oxidative phosphorylation → cristae/inner membrane of mitochondria
what does glycolysis produce?
ATP
glycolysis is the first stage of…
aerobic and anaerobic respiration
what type of process is glycolysis?
anaerobic
three main steps of glycolysis:
1) glucose is phosphorlyated into glucose phosate (using 2 ATP)
2) glucose phosphate is converted into 2 triose phosphates
3) triose phosphate is oxidated to produce pyruvate
net gain of glycolysis:
-4 ATP (net gain 2 as 2 were used at the start)
-2 reduced NAD (the co enzyme used in respiration) → NAD picks up a hydrogen
-2 pyruvates
where do the products of glycolysis go?
pyruvate and NADH are actively transported into the mitochondrial matrix for the link reaction
steps of the link reaction:
1) pyruvate is oxidised into acetate (carbon dioxide released)
2) NAD accepts hydrogen and becomes reduced NAD (NADH)
3) acetate combines with coenzyme A to produce acetylcoenzyme A
what does the link reaction produce?
the link reaction occurs twice for every glucose molecule:
2 acetylcoenzyme A
2 carbon dioxides released
2 reduced NAD
where do the products of the link reaction go?
acetylcoenzyme A enters the krebs cycle
steps of the krebs cycle:
1) acetylcoenzyme A reacts with a 4 carbon molecule, producing a 6 carbon molecule that enters the krebs cycle
(the coenzyme is then released so it can be reused in the link reaction)
2) in a series of redox reaction, the krebs cycle generates reduced coenzymes and ATP by phosphorylation (carbon dioxide is also lost)
what are the products of the krebs cycle:
per cycle:
-3 reduced NAD
-1 reduced FAD
-1 ATP
- 2 CO2
per glucose:
-6 NADH
-2 FADH
-2 ATP
-4 CO2
what occurs during oxidative phosphorylation?
1) all of the coenzymes that were produced release their hydrogen (splits into protons and electrons)
2) the electrons are transported along the electron transport chain, this releases energy
3) the energy is used to actively transport protons from the matrix into the inter membrane space
4) an electrochemical gradient is created & protons can move down their gradient by facilitated diffusion through ATP synthase
5) ATP synthase phosphorylates ADP to produce ATP
6) at the end of the electron transfer chain, electrons are picked up by oxygen, oxygen also accepts protons when they pass through, this is how water is formed
7) oxygen is the last electron acceptor
where does anaerobic respiration occur?
in the cytoplasm of the cell
products of anaerobic respiration in plants and microbes:
ethanol & carbon dioxide
