Cellular respiration Flashcards
(7 cards)
4 reasons why cells need energy
- mechanical work
- moving stuff in the cell - make new material
- growing or replacing cells - transport
- moving material out of the cell across the membrane - maintain order
- keep everything in cell together and in the right place
explain the structure of the mitochondria
- has 2 membranes
- outer membrane
- inner membrane that is folded (cristae) to maximize surface are - has 2 compartments
- matrix (inside of inner membrane)
- intermembrane space between 2 membranes
what is the first stage of cellular respiration and what happens
Glycolysis
- in the cytosol the glucose (6C molecule) is converted into 2 pyruvate molecules (2 -3C molecules)
- 2 ATP is generated
- electrons are transferred to the high energy electron carrier NAD+ making NADH
what is the second stage of cellular respiration and what happens
Pyruvate Oxidation and Citric Acid Cycle
- in the mitochondria matrix 2 pyruvate molecules (2-3C molecules) are converted into 2 Acetyl CoA molecules that enter the citric cycle.
- this generates ATP and high energy electron carries NADH and FADH2
what is the third stage of cellular respiration and what happens - part 1
the electron transport chain
- electron carriers NADH and FADH2 shuttle high energy electrons to the inner mitochondrial membrane
- these electrons move through protein complexes embedded in the inner membrane
- as electrons move, H+ (protons) are pumped across the membrane which creates a chemical gradient of H+ in the intermembrane space
what is the third stage of cellular respiration and what happens - part 2
chemiosmosis
- inner mitochondrial membrane contains a protein complex called ATP synthase
- protons move from a high to low concentration through ATP synthesis
- energy from the protons generate ATP
why is ATP important
- ATP enables the controlled release of energy as it is releases in ‘packets’
- the cell continuously uses and regenerates ATP
