General Respiration and Glycolysis Flashcards
What are the steps of respiration?
- Glycolysis
- The Link Reaction
- Kreb’s Cycle
- Oxidative Phosphorylation
Where does glycolysis occur?
Cytoplasm [inc. sarcoplasm of muscle cells]
Does glycolysis occur in aerobic or anaerobic respiration?
Both ;-]
Is oxygen needed for glycolysis?
No
What substance is needed for glycolysis?
Glucose
Where is glucose supplied from for glycolysis?
Conversion of glycogen stores in muscle/liver cells
What is glucose converted to in glycolysis?
2 molecules of pyruvate
What are the 2 stages of glycolysis?
- Phosphorylation
- Oxidation
What is needed for glucose to be converted at the beginning of glycolysis and why?
Input of energy from 2x ATP as glucose is stable and unreactive
What’s added to glucose in glyoclysis phosphorylation and what does this do?
2 Pi groups are added to glucose from 2ATP molecules, turning them into 2ADP
Increases reactivity of glucose and splits it
What is glucose split into in the phosphorylation of glucose in glycolysis?
Two molecules of 3 carbon triose phosphate
In oxidation in glyoclysis, what are the 2 molecules of triose phosphate converted to?
Oxidised into 2 molecules of pyruvate
What does the conversion of triose phosphate into pyruvate in glycolysis release and what do they do?
4 molecules of Pi that combine with 4ADP to form 4ATP
What is the formation of ATP from the phosphate released by formation of pyruvate in glycolysis known as and why?
Substrate level phosphorylation - energy and Pi comes from triose phosphate molecules to form ATP
What else other than 4Pi is released from oxidation of triose phosphate in glycolysis?
2H+
What does the 2H+ released from oxidation of triose phosphate do?
Reduces “NAD” to “reduced NAD”
What are the products of glycolysis?
- Net gain of 2 ATP
- 2 Reduced NAD
- 2 Pyruvate
What does the reduced NAD from glycolysis go on to do?
Become a co enzyme in oxidative phosphorylation
What does the pyruvate from glycolysis go on to?
The matrix of the mitochondria for the link reaction
Glycolysis is only a x oxidation of glucose
Partial
What is needed to completely oxidise glucose?
Oxygen
What is end point inhibtion?
When the end product inhibits an early step in the metabolic pathway, controlling the whole process
What happens if there is enough ATP produced from glycolysis? 2
- ATP inhibits the enzyme involved in glucose phosphorylation
- Changes its shape so it becomes inactive and doesn’t catalyse the reaction
What happens when ATP from glycolysis is broken down? 2
- The enzyme involved in glucose phosphorylation is converted back into active form
- Catalyses glucose phosphorlyation
Give the equation for aerobic respiration
C6H12O6 + 6O2 ——] 6H2O + 6CO2
What type of molecule is glucose?
A respiratory molecule - one that can be respired
What is glucose split into during respiration overall?
CO2 and H2
What is CO2 from respiration considered?
A waste product
What is H2O formed in respiration?
H2 produced from glucose combines with atmospheric O2 to form H2O
What is released when H2O is formed in respiration and what is it used to do?
Large amount of energy - used to phosphorylate ADP to ATP
Why is a large amount of energy released when H2O is formed?
- Glucose contains a hydrogen carbon bond which is not as strong as the hydrogen oxygen bond in water
- The input of energy needed to break the C-H bond is less than the input of energy released when the O-H bonds in water are made
- There is a net release of energy
What type of respiration is ideal for endurance type excercise?
Aerobic respiration
Why is aerobic respiration ideal for endurance type exercise? 3
- Increase in blood supply to muscles
- Ensures higher O2 supply to muscle cells
- Aerobic respiration can regenerate ATP quickly as it is broke down
What is endurance type exercise?
Exercise sustained for long periods of time e.g marathons
What do glycolysis, the link reaction and krebs cycle do in respiration?
Provide products for oxidative phosphorylation where most ATP is produced
How is ATP synthesised?
Phosphorylation of ADP
What enzyme is ATP synthesis catalysed by?
ATP synthase
Why is energy required to synthesise ATP?
- Phosphate ions are hydrated
- To make ATP, phosphate ions must be seperated from water
- This requires energy
What is stored in the 3rd phosphate bond in ATP?
Chemical potential energy
Where is chemical potential energy stored in ATP?
The 3rd phosphate bond
Why is chemical potential energy stored in the 3rd phosphate bond in ATP?
- Energy is required to make the 3rd phosphate bond
- So ATP in water is higher in energy than ADP and Pi in water combined
How is ADP formed?
Hydrolysis of ATP, removing one phosphate group
What enzyme is ADP formation catalysed by?
ATPase
What is released when ATP is hydrolysed?
Energy
Why is energy released when ATP is hydrolysed? 2
- Pi becomes hydrated when removed
- Energy is released as bonds form between water and phosphate
What are uses of ATP? 2
- Raises temperature of the cell
- Metabolic reactions
What metabolic reactions is ATP used for? 3
- Muscle contraction
- Protein synthesis
- Active Transport
