Cellular Respiration Flashcards
What does NADH and FADH2 release and what do they do?
Release high energy electrons which cascade down the chain releasing energy
What is the energy produced from NADH and FADH2 used for?
Used to pump H+ ions across the inner mitochondrial membrane
What does the return flow of H ions do?
Drives ATP synthase and produces the bulk of ATP
What is the final electron acceptor?
Oxygen
What does the final electron acceptor combine with and what does this form?
Oxygen combines with hydrogen ions and electrons to form water
How many molecules of ATP does the ETC produce?
34 molecules of ATP per molecule of glucose
What is ATP synthase?
An enzyme which generates ATP from H+ ions moving from the outside of the membrane back into the matrix of the mitochondria
What does the flow of H+ ions cause part of ATP synthase to do?
Causes part of ATP synthase to rotate (kinetic energy) which catalyses the synthesis of ATP from ADP + Pi
What does each NADH + FADH2 molecule produce?
3ATP
What are starch and and glycogen?
Carbohydrates
What are starch and glycogen made up of?
Chains of glucose molecules
What can starch and glycogen be broken down into?
Can be broken down into glucose and used as a respiratory substrate
What do fats contain twice as much as than protein and carbohydrates?
Energy
What can fats be broken down into?
Fatty acids and glycerol
What is glycerol converted to? Why?
Glycolytic intermediate for use in glycolysis
What are fatty acids converted to? What then happens?
Acetyl co-enzyme A which then enters the Citric Acid Cycle
What are proteins composed of?
Amino acids
What happens to excess amino acids?
Can be lost in urea or used as a respiratory substrate by conversion into Pyruvate, Acetyl co-enzyme A or citric acid cycle intermediates
Why are proteins the last food group to be broken down?
Important for growth and repair of tissues, e.g muscles
What can glycolysis be slowed down by?
Feedback inhibition
What happens when the cell acquires more ATP than it needs?
Inhibits phosphofructokinase
What happens when ATP is low again during feedback inhibition?
The enzyme works as normal, speeding up glycolysis
When does inhibition occur?
When there is a high concentrate of citrate
What happens when levels of citrate drop during feedback inhibition?
The enzyme is no longer inhibited, speeding up rate of glycolysis
Why is feedback inhibition important?
It prevents the build up of an intermediate which is not needed
ATP is only produced when required and therefore resources are conserved
What are the three stages of respiration?
Glycolysis
Citric Acid Cycle
Electron Transport Chain
What is the speed of contraction for a slow twitch?
Slow
What is the speed of contraction for a fast twitch?
Fast
What is the length of time sustained for a slow twitch?
Long
What is the length of time sustained for a fast twitch?
Short
What is the speed at which fibre becomes fatigued for slow twitch?
Slow
What is the speed at which fibre becomes fatigued for fast twitch?
Fast
What respiratory pathways are normally used to generate ATP for slow twitch?
Glycolysis and aerobic
What is the respiratory pathway normally used to generate ATP for the fast twitch
Glycolysis only
What is the number of mitochondria present in slow twitch?
Large
What is the number of mitochondria present for fast twitch?
Small
What do muscle cells contain?
An oxygen storing protein called myoglobin
Why does myoglobin have a higher affinity for oxygen than haemoglobin?
So that it can store and transport oxygen from the blood to be used by the muscle cells
