Respiration

?
Where does glycolysis take place?
In the cytoplasm of the cell
1 of 43
Where does the link reaction take place?
In the matrix of the mitochondria
2 of 43
Where does the Krebs Cycle take place?
In the matrix of the mitochondria
3 of 43
What three things does oxidation refer to?
Loss of electrons, addition of oxygen, loss of hydrogen
4 of 43
What three things does reduction refer to?
Gain of electrons, loss of oxygen, addition of hydrogen
5 of 43
State 6 possible uses of energy in biological organisms
Cell division/ Secretion-formation of vesicles/ production of substances e.g. enzymes/ Maintenance of body temp in endotherms/ Bioluminescence/ Production of electricity-electric eel
6 of 43
Why is respiration rate affected by temperature?
Glucose is a stable molecule so an activation energy must be overcome in order to convert it to a less stable molecule which is then broken down more easily
7 of 43
Define energy
The capacity to do work
8 of 43
Why is ATP known as the universal energy currency?
1) it occurs in all living organisms 2) it can be used by cells in small amounts
9 of 43
Some energy released from the hydrolysis of ATP is in the form of heat. This may be thought of as wasteful/inefficient. Explain why this isn't the case.
Heat helps keep living organisms warm and enables their enzyme-catalysed reactions to proceed at thier optimum rate.
10 of 43
What is the first stage of glycolysis?
Two ATP molecules are used to convert glucose into hexose phospahte
11 of 43
During the third stage of glycolysis, why does hexose bisphosphate spontaneously split in two?
Because its an unstable molecule
12 of 43
Explain how a single triose phosphate molecule gets converted to pyruvate, during glycolysis
NAD removes a H2, Two ADP+Pi are converted into ATP, Pyruvate is the resulting molecule
13 of 43
What needs to be present for glycolysis to enter the link reaction?
Oxygen
14 of 43
What are the two main stages in glycolysis?
Phosphorylation and oxidation
15 of 43
Why is there an overall net gain of 2 ATP?
Because glycolysis yields 4ATP, but 2ATP were used to initiate the reaction
16 of 43
What does NAD stand for?
Nicotinamide adenine dinucleotide
17 of 43
How does NAD become reduced?
The nicotinamide ring accepts two hydrogen atoms
18 of 43
Describe how hexose bisphosphate is formed from a molecule of glucose.
Glucose is phosphorylated by adding a phosphate from ATP, creating hexose phosphate. Hexose phosphate is phosphorylated by ATP to form hexose bisphosphate. Two ADP are produced
19 of 43
What is the product of the Link Reaction?
Acetyl Coenzyme A
20 of 43
Describe the movement of electrons in oxidative phosphorylation
The electrons move along the electron transport chain, releasing energy at each electron carrier. Finally they are oassed onto oxygen as it's the final electron acceptor
21 of 43
How many carbons is a pyruvate molecule made up of?
3
22 of 43
What is another name for the Link Reaction?
Oxidative deocarboxylation
23 of 43
How many molecules of CO2/ NADH/FADH2/ATP are produced PER TURN of the Krebs cycle?
2 CO2/ 3 NADH/ 1 FAD/ 1 ATP
24 of 43
What is the phosphorylation occuring in the Krebs cycle known as?
Substrate level phosphorylation
25 of 43
In the Krebs cycle, how is the 6-Carbon molecule citrate produced?
The 2-Carbon Acetyl CoA from the link reaction combines with the 4-Carbon molecule oxaloacetate
26 of 43
Name three things that the mitochondrial matrix contains.
Mitochondrial ribosomes/ looped mitochonndrial DNA/ enzymes for the Link Reaction and Krebs Cycle
27 of 43
How is the lipid composition of the inner membrane of the mitochondria different to the outer membrane?
It is less permeable to small ions e.g. H+
28 of 43
How is NADH + H+ reoxidised in the first stage of oxidative phosphorylation?
By the action of NADH dehyrogenase
29 of 43
Why is oxygen so important for aerobic respiration?
It accepts the e- and H+ to form H2O. Without it there would be a backup of H+ and e-.
30 of 43
Why is cyanide a lethal poison?
It inhibits the cytochrome oxidase complex (an electron carrier) which catalyses the formation of water from Oxygen, H+ and e-
31 of 43
What is chemosmosis?
The flow of protons resulting from the formation of a proton gradient
32 of 43
In what 2 ways can electrons become excited?
Electrons present in pigment molecule (e.g. chrlorophyll) are excited by absorbing light from the sun. High energy electrons are released when chemical bonds are broken in respiratory substrate molecules e.g. glucose
33 of 43
What allows the synthesis of ATP from ADP and Pi?
A conformational (shape) change occurs in the ATO synthase as H+ diffuse through their associated channels
34 of 43
Which mitochondrial membrane is a) impermeable to protons and b) which has a low degree of permeability?
inner-impermeable outer-low permeability
35 of 43
What 3 reasons lead the actual yeild of ATP to be lower than the theoretical yield?
ATP used to actively transport pyruvate into mitochondria/ some ATP used to transport reduced NAD made during glycolysis into mitochondria/ some H+ leak out through outer mitochondrial membrane
36 of 43
Describe the ethanol fermentation pathway.
Pyruvate is decarboxylased-releasing CO2-forming ethanal/reduced NAD is reoxidised converting the ethanal into ehtanol
37 of 43
Why is anaerobic respiration in mammals more efficient than in yeast?
Because the lactate can be concverted into pyruvate or glycogen once oxygen becomes available again, meaning the energy associated with pyruvate isnt wasted however the ethanol pathway can't be reversed and so energy in ethanol is wasted
38 of 43
What is the formula of the respiratory quotient?
RQ=volume of CO2 given out/ volume of O2 taken in
39 of 43
What is the RQ value for a carbohydrate?
1
40 of 43
What is the RQ value for a lipid?
about 0.7
41 of 43
What is the RQ value for a protein?
0.8-0.9
42 of 43
State 2 major limitations of RQ.
Substances are rarely completely oxidised and organisms rarely respire a single food source
43 of 43

Other cards in this set

Card 2

Front

Where does the link reaction take place?

Back

In the matrix of the mitochondria

Card 3

Front

Where does the Krebs Cycle take place?

Back

Preview of the front of card 3

Card 4

Front

What three things does oxidation refer to?

Back

Preview of the front of card 4

Card 5

Front

What three things does reduction refer to?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Cellular processes resources »