cellular respiration Flashcards
what is an energy carrier?
ATP
why does the cell need energy?
- for mechanical work - e.g. motor proteins
- to make new materials- e.g. for growth & replacement
- for transport - e.g. transport of molecules across membranes
- to maintain order
what is the site of cellular respiration?
mitochondria
what is the cellular respiration equation?
C6H12O6 + 6O2 -> 6CO2 + 6H2O + Energy
what are the two important compartments for respiration?
- matrix
- inner membrane
what is the structure of mitochondria?
-1-10 μm long
-1-1000’s per cell (depends on energy demand)
- Contains mitochondrial DNA & ribosomes (Produces some but not all mitochondrial proteins)
how many membranes do the mitochondria have?
Has two membranes: inner & outer mitochondrial membranes (lipid bilayers)
what are the distinctable functions of the inner membrane of mitochondria?
- Inner membrane highly folded (cristae) functionally important
- Intermembrane space is functionally important
-Mitochondrial matrix inside the inner membrane
harvesting chemical energy from glucose occurs in how many stages?
- Harvesting chemical energy from glucose occurs in three stages, each in a different location
- Compartments of the mitochondrion are essential for cellular respiration
what happens in cellular respiration during Stage 1 of glycolysis?
in the cytosol = sugar (glucose is split and converted into smaller molecules called pyruvate
- glucose is energy-rich molecule = splitting it in two releases energy = form of ATP and NADH
what is generated in cellular respiration during Stage 1 of glycolysis?
Generates:
- 2ATP – energy carrier
AND
- electrons are transferred to the high-energy electron carrier = NAD+ making NADH
what is the second stage of cellular respiration?
Stage 2 – Pyruvate Oxidation & Citric Acid Cycle
what happens and generates in cellular respiration during Stage 1 of the Pyruvate Oxidation & Citric Acid Cycle?
- the pyruvate in the Mitochondrial Matrix
- 3C Pyruvate MOLECULE is converted into 2C Acetyl CoA molecule splitting which means there are more high energy electrons
- Acetyl CoA enters the citric acid cycle and gets broken down completely.
- output is an energy carrier ATP and high energy electron carriers NADH & FADH2 (FADH Is only 2 because the high energy is not as high as NADH)
what is cellular respiration: stages 1 & 2 - summary?
Started with glucose –> Output is ATP and some NADH & FADH2
what is the third stage of cellular respiration?
oxidative phosphorylation
what happens in cellular respiration during the 2 parts in the third stage of cellular respiration?
Inner Membrane of the Mitochondrion
Two Parts:
- electron transport (electrons from NADH and FADH2) - proton gradient
- Chemiosmosis (ATP production)
what can’t get electrons out of the electron transport chain if it’s not present?
oxygen - necessary to accept electrons from the electron transport chain
what happens in cellular respiration during oxidative phosphorylation’s chemiosmosis?
- The inner mitochondrial membrane contains the protein complex: ATP synthase
- This complex spans the membrane from the intermembrane space to the mitochondrial matrix
- The proton gradient across the inner membrane powers ATP synthesis
in part 2 of chemiosmosis, what happens to the ATP synthase?
ATP Synthase converts:
ADP + Pi —> ATP
what is the summary of cellular respiration?
- Chemical energy is converted from one form to another
- From glucose to ATP – an energy carrier used by the cell
- The structure of the mitochondrion enables the proton gradient to be established across the inner membrane and this drives the production of ATP
what does ATP enable?
ATP enables the controlled release of energy
what powers cellular activity?
ATP
what happens when there is uncontrolled ATP release?
explosive release of light and heat energy - can cause damage to cells
whats regeneration is essential?
ATP
- The cell continuously uses and regenerates ATP
