Download Energy and Glycolysis

Energy Transfer in Living
Things Part I
Energy
Glycolysis
Fermentation
Central Questions
–What is the role of ATP in the cell?
–Describe what happens in
glycolysis.
–Where does glycolysis occur?
–What is fermentation? Describe the
2 main types of fermentation.
Energy in Living Things
Getting Energy…
• All living things obtain and use
energy
• This energy is used to carry out
the functions that keep the
organism alive
• Energy is used to alter chemicals,
move molecules around in the cell
and much more
• All living things obtain energy, but get it
from different places
–Autotrophs – make their own food.
• Photosynthesis – Uses energy from
the sun to make glucose. It’s carried
out by plants and some microbes.
Getting Energy…
• Heterotrophs – get energy from
eating autotrophs or other organisms.
–Animals eat autotrophs or other
organisms that ate some
–Fungi absorb food from their
surroundings
–Unicellular organisms get energy
various ways, representing either or
both of the above
Energy in Living Things
• The organic compounds contain
energy, but the cell can’t use it
that form
• Because of that cells need an
energy carrying molecule
• Virtually all cells use the energy
transfer molecule ATP to move
energy around
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ATP
• ATP gives up a phosphate (P)
to “do work”, making it ADP
• ADP can get a P back, to
change back to ATP, during
respiration or photosynthesis
• ATP has three P’s (T is for tri)
and is a ‘charged battery’
• ADP has two P’s (D is for di)
and is the ‘uncharged battery’
ATP – ADP Cycle
Cellular Respiration
• Cellular Respiration is the
process by which food
molecules are used to release
energy (making ATP)
• Glucose is the preferred food
for this, but other
macromolecules have ways of
entering the process
Glycolysis
Making ATP in Glycolysis
• Not all organisms do cellular
respiration the same way, but they all
start with glycolysis
• Glycolysis is the breaking of a glucose
molecule into two pyruvate molecules
• Glycolysis takes place in the
cytoplasm
• Glycolysis does two things: make
some ATP and prepares for future
steps
• Two parts: Energy investment and
Energy payoff
• Energy investment: two ATP are used
• Energy payoff: four ATP are made
• Overall 2 ATP and 2 pyruvate
molecules are made
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Now what?!
• There are two options at this point
• We move on to aerobic respiration,
using oxygen in the mitochondria to
make much more ATP (next set of
notes)
OR
• End of the road…we make waste
products and recycle our NADH to
NAD+ (FERMENTATION)
Fermentation
• Fermentation follows anaerobic respiration
(doesn’t use oxygen)
• Lactic Acid Fermentation
• Makes lactic acid
• Used by bacteria and animals
–Ethyl Alcohol Fermentation
• Makes ethyl alcohol (ethanol) and
carbon dioxide
• Used by yeast
Central Questions
–What is the role of ATP in the cell?
–Describe what happens in
glycolysis.
–Where does glycolysis occur?
–What is fermentation?
–Describe the 2 main types of
fermentation.
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