Transcript ATP/ADP CYCLE

ATP/ADP CYCLE
Ch. 9
ATP (adenosine triphosphate) is a type of nucleotide
consisting of the nitrogenous base adenine, the sugar ribose, &
a chain of three phosphate groups.
The bonds between phosphate groups can be
broken by hydrolysis.
So what?
• Energy is stored (potential E) in these bonds.
• So?....
• The breaking of the chemical bond releases the energy
ATP + H2O→ ADP + P + ENERGY
ATP
• Energy released from ATP powers cellular work
• A cell does 3 main kinds of work:
• Mechanical work, beating of cilia, contraction of muscle
cells, & movement of chromosomes
• Transport work, pumping substances across membranes
against the concentration gradient (active transport)
• Chemical work, driving reactions such as the synthesis of
polymers from monomers
• It is the gasoline for the cell!!
Endosymbiosis Theory
• Mitochondria consume oxygen to efficiently gather E from carbon sources
like glucose, producing CO2 & H2O.
• Chloroplasts consumes H2O & CO2 as it captures & converts light E into
the chemical E of glucose, releasing oxygen in the process.
• Endosymbiotic theory proposes that the mitochondria & chloroplasts were
once prokaryotic cells, living inside larger host cells.
• The prokaryotes may have been parasites or even an intended meal for the
larger cell, somehow escaping digestion.
Evidence of Endosymbiosis:
BOTH mitochondria AND chloroplasts…
• 1. Are just about the same size
as bacteria
• 2. Reproduce only through a
process similar to binary fission
• 3. Contain DNA that is
different from that of the cell
nucleus & is similar to that
of bacteria (its circular in shape
& small).
• 4. These organelles'
ribosomes are like those found
in bacteria