Cellular Respiration (from maam) Flashcards
Parts of the mitochondria
- outer membrane
- inner membrane
- intermembrane space
- crista
- matrix
- serves as a transport and signaling hub, and harbors numerous metabolic enzymes
- enclosed by the outer and the inner membrane of the mitochondria
intermembrane space
- folds within the inner mitochondrial membrane
- increased surface area in which chemical reactions, such as the redox reactions, can take place.
Mitochondrial cristae
- site of the tricarboxylic acid (TCA) cycle, a series of enzymatic reactions initiated by the conversion of pyruvate and fatty acids to acetyl coenzyme A (acetyl-CoA).
Mitochondrial matrix
Overview of Cellular Respiration
- Food breakdown
- Glycolysis
- Aerobic respiration
- Fermentation
Before food can be converted into ATP, it must be broken down into simpler forms of sugar, lipid, or amino acids
Stage 1: food breakdown
The simple molecules from stage 1 must be converted into a intermediate product before it can be converted into ATP.
Stage 2: glycolysis
in this step, food is converted into ATP
Stage 3: aerobic respiration
in the absence of oxygen, cells undergo this to produce ATP
fermentation
Main types of energy-releasing pathways
- Anaerobic pathways
- Aerobic pathways
- Evolved first
- Don’t require oxygen
- Start with glycolysis in cytoplasm
- Completed in cytoplasm
anaerobic pathways
site of anaerobic pathways
cytoplasm
- Evolved later
- Require oxygen
- Start with glycolysis in cytoplasm
- Completed in
mitochondria
aerobic pathways
where aerobic pathways are completed
mitochondria
where aerobic pathways are started
cytoplasm
basic units of proteins
amino acids
basic units of polysaccharides
simple sugars
basic units of fats
- fatty acid
- glycerol
Two stages of glycolysis
- energy-requiring steps
- energy-releasing steps
ATP energy activates glucose and its six-carbon derivatives
energy-requiring steps
- The products of the first part are split into three-carbon pyruvate molecules
- ATP and NADH produced
energy-releasing steps
Net energy yield from glycolysis:
energy requiring steps
2 ATP invested
Net energy yield from glycolysis:
energy releasing steps
- 2 NADH
- 4 ATP
Net yield of glycolysis
- 2 ATP
- 2 NADH
Stage 3: Aerobic respiration
- Kreb cycle
- Electron transport chain
One molecule of glucose is entirely consumed in the process of cellular respiration and converted to
six (6) molecules of CO2
Energy of glucose is preserved in
- 4 ATP molecules
- 10 NADH electron carriers
- 2 FADH2 electron carriers
Krebs cycle:
The NADH and FADH2 carry their high-energy electrons to the __ __ __
inner mitochondrial membrane
Krebs cycle:
NADH and FADH2 in the inner mitochondrial membrane transfer the high-energy electrons to a series of membrane-associated carriers - __ __ __
electron transport chain
Three of these carriers are __ __ that pump protons __ of the matrix
- protein complexes
- out
Electron transport chain
- Protein complex I
- Protein complex II
- Protein complex III
___ activates all three pumps in the electron transport chain
NADH
___ activates only two pumps
FADH2
FADH2 activates what pumps
- protein complex II
- protein complex III
proton pumps lead to an ___ in proton concentration in the intermembrane space
increase
The proton gradient induces the protons to reenter the matrix through __ __ __
ATP synthase channels
The proton reentry drives the synthesis of ATP by ___
chemiosmosis
overview of the electron transport chain and chemiosmosis
- Electrons harvested and carried to transport system
- Electrons provide energy to pump protons across membrane
- Oxygen joins with protons to form water
- Protons diffuse back in, driving synthesis of ATP
Typical energy yield of aerobic respiration
36 ATP
Overview of Anaerobic Respiration
Pyruvate + NADH2+ -> lactic acid + NAD+
or
Pyruvate + NADH2+ -> ethanol + CO2 + NAD+
Glycolysis happens where
cytoplasm
citric acid cycle happens where
matrix of mitochondria
electron transport chain and oxidative phosphorylation happens where
inner membrane of mitochondria
Overview of Aerobic Respiration
C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O + ATP (energy)
