Transcript How do they (or we) use the glucose?

Cellular Respiration
• What is it?
extracting the energy from
glucose and using it to charge
ADP to make ATP
• Who performs cell respiration?
One way or another, EVERY
LIVING THING
What’s the BIG PICTURE
• Well…that depends on the conditions.
– If there is no oxygen (or no mitochondria), only
steps in the cytoplasm happen
– With O2 more
energy can be
“extracted”
from glucose
to put into
ATP molecules
Cellular Respiration
–What are the steps?
–Anaerobic cell respiration
• Glycolysis + Fermentation
–Aerobic cell respiration
• Glycolysis + Krebs Cycle + ETC
• Purpose is the same, just different
methods.
Cell Respiration - Two types
- Anaerobic respiration: O2 not
needed;
- done by yeast, certain bacteria,
exhausted muscle cells of animals
- produces 2 ATP per glucose
- Two steps:
- glycolysis
- fermentation: alcohol or lactic acid
Step 1
• Glycolysis – “glucose splitting”
–Glucose split into 2 pyruvate
–2 ATP used
–4 ATP and 2 NADH made
–Happens in cytoplasm
–First step of BOTH ANAEROBIC
AND AEROBIC RESPIRATION
Steps
• Fermentation –
- conversion of pyruvate to
Alcohol and CO2 (yeast) or Lactic
acid (exhausted muscle cells)
- no more ATP generated
- Purpose: “empties” electron
carriers so glycolysis can happen
again
Cell Respiration - SECOND type
- Aerobic respiration: O2 needed
- Requires mitochondria
- Produces 36 ATP per glucose
- Three steps:
- Glycolysis (followed by shuttle step)
- Krebs
- Electron transport Chain
Equation for Aerobic C. R.
C6H12O6
+ 6O2 --- 6CO2+ 6H2O
ADP + P
ATP
- getting the energy back out of
storage
The equation that we use for cellular respiration is really
AEROBIC cell respiration
Mitochondria
• Krebs cycle takes place
in the matrix
– Purpose: to break
apart C-C and C-H
bonds
– Energy transferred to
electron carriers and a
few ATP
Aerobic Respiration Steps
Step 1
• Glycolysis: EXACTLY the same
as the beginning of anaerobic
respiration
–BUT next step is different…
Step 1.5
• Shuttle step– converts pyruvate
to Acetyl-coA and moves it into the
mitochondria
–Releases some CO2, fills up some
electron carriers (2 NADH)
–Has many names: prep step,
grooming step, etc.
Step 1 – Preparation for Krebs
Cycle
Step 2
Krebs cycle –
Happens in mitochondrial matrix
PURPOSE
1. Oxidizes pyruvate
2. Fills up e- carriers (FAD, NAD)
– 2 acetyl CoA broken down to 4 CO2
–2 ATP, 2 FADH, 6 NADH made PER
GLUCOSE
Krebs Cycle
• (Citric Acid Cycle)
Step 3
• Electron Transport chain –
–All the filled electron carriers
(NADH, FADH2) dump their
electrons here
–Energy in electrons is transferred to
to make 32 ATP
–“dead” Electrons “caught” by O2 to
make H2O
Oxidative Phosphorylation
ETC + Chemiosmosis
Steps
• Final Tally: Create a table in
your notes packet
Respiration
• What do we notice about
respiration in comparison to
Photosynthesis?
THE BIG PICTURE
• Is energy recycled?
• What about the reactants and
products??