Cellular Respiration Flashcards
cellular respiration
the process of capturing the energy released by breaking down molecules and using it to build ATP
Organic compounds +O2–>CO2+H2O+Energy (ATP + heat)
what can be used in cellular respiration
proteins, carbs, lipids
glucose
6 carbon sugar
C6H12O6
reduction
the gain of one or more electrons in any atom, ion, or molecule
often brings the gain of a H+ ion because it neutralizes the charges
oxidation
the loss of one or more electrons
glycolysis
one 6 carbon molecule to two 3 carbon molecules aka pyruvates
energy is released and ATP is made
some of the electrons from the broken bonds is transferred to ATP, some transferred to NADH electron
NADH molecules store excess energy
anaerobic reaction
requires activation energy
every cell can do it
1 glucose +2ATP–>4ATP + 2 pyruvate + 2NADH
net gain=2 ATP, 2 pyruvate, and 2 NADH
transition
2 pyruvate molecules are broken down again and become acetyl CoAs
each lose 1 carbon and that single carbon molecule combines with oxygen to form CO2
energy is released and a nucleotide is converted
2 more molecules of NADH are formed and energy is temporarily stored on an electron of NADH
Acetyl CoA’s move into mitochondrion
aerobic reaction
products: 2 acetyl CoA’s, 2 CO2, 2 NADH
citric acid cycle
acetyl CoA’s combine with oxoalacetate to make citric acid (6 carbon compound)
during the cycle, the citric acid molecule is stripped of two of its carbon molecules, which then combine with O2 to form CO2
energy is released and stored on electrons
oxaloacetate stays in the cycle and continues to break down acetyl CoA
products per cycle: 3 NADH, 1 FADH and 1 ATP, 2 CO2
oxidative phosphorylation
electron breaks off of NADH molecule so you get NAD+ and H+
electron goes down the ETC, creating an H+ proton gradient
H+ proton gradient then causes ADP and P to form ATP
electron transport chain
group of protein complexes embedded in the inner mitochondrial membrane
each protein accepts high energy electrons and uses some of the energy to drive H+ pumps
creates an H+ gradient
physical place where we use oxidative phosphorylation
steps of the electron transport chain
o Phosphorylate ADP to ATP by taking electrons off of the NADH and FADH2 molecule (oxidized)
o When we break apart these NAD/H+ molecules, we are left with a bunch of H+ ions, too acidic, will denature our proteins
o Body tries to get rid of it but uses its energy to create ATP
o Creates a H+ gradient and pump them to one side
o Need energy from the electrons for the pump
o Generates a lot of ATP
o H+ ion will be combined with the electron and a molecule of oxygen to create water
Role of oxygen
glycolysis-no O2
transition-O2
citric acid cycle-O2
Electron transport-O2 required to accept the electron
anaerobic metabolism
some forms of exercise
convert 2 pyruvate to 2 lactic acid (endergonic reaction)
stop here
1 glucose yields 2 ATP
contributes to a lower pH
not sustainable for very long in eukaryotic cells
anaerobic respiration
• Lactic acid is the byproduct of human anaerobic respiration
• Yeast can undergo anaerobic respiration but produce ethyl alcohol and CO2 instead of lactic acid
o Beer and champagne
o Yeast break down the sugars in the product and create an alcohol byproduct
acetyl CoA
- Simple and common molecule
- It can be made from pyruvate OR from lipids and a few amino acids
- Lipids and proteins can contribute to aerobic metabolism
- Bc we begin and end the citiric acid cycle with oxaloacetate, as long as Acetyle CoA is available, the cycle can go on
- Lipids Break glycerol into two carbon chunks→a lot of acetyl CoA
