Summary Molecular Biology of the Cell 2 (book) (WBFA007-04)
Summary Regenerative Medicine
All for this textbook (62)
Written for
Rijksuniversiteit Groningen (RuG)
Farmacie
Molecular Biology Of The Cell (WBFA00604)
All documents for this subject (7)
Seller
Follow
esmstegeman
Reviews received
Content preview
Chapter 14: Energy Conversion: Mitochondria and Chloroplasts
energy-converting organelles:
o mitochondria produce ATP by oxidative phosphorylation
o chloroplasts harness solar energy to produce ATP by photosynthesis
occur only in plants and green algae
chemiosmotic coupling signifies a link between the chemical bond-forming
reactions that generate ATP (“chemi”) and membrane transport processes (“osmotic”)
o stage 1: energy from sunlight/food is
captured to generate an
electrochemical
proton gradient
across a membrane
o stage 2: ATP
synthase embedded
in the lipid bilayer of a
membrane harnesses
the electrochemical proton gradient across the membrane,
using it as a local energy store to drive ATP synthesis
NAD = electron carries takes up two electrons and one H+
+
NADH
two photosystems
Both mitochondria and chloroplasts make use of an electron-transfer chain to
produce an H+ gradient that powers reactions that are critical for the cell
The mitochondrion
Mitochondria are remarkably dynamic and plastic, moving about the cell, constantly
changing shape, dividing, and fusing
o are often associated with the microtubular cytoskeleton
o pyruvate is imported into the mitochondrion and ultimately oxidized by O2 to
CO2 and H2O ATP
Interaction between mitochondria and endoplasmic reticulum
inner membrane surrounds internal mitochondrial matrix
o folded to form invaginations known as cristae
crista space – crista membrane is continuous with inner boundary
membrane
crista junctions = narrow membrane tubes or slits; formed where their
membranes join
, o inner boundary membrane
o intermembrane space
outer mitochondrial membrane freely permeable to ions and to small molecules
as large as 5000 daltons
Inner mitochondrial membrane
contain the machinery for electron
transport and ATP synthesis
Inner mitochondrial membrane is a
diffusion barrier to ions and small
molecules
o selected ions, most notably
protons and phosphate, as well
as essential metabolites such as
ATP and ADP, can pass through
it by means of special transport
proteins
o protein complexes of the
respiratory chain =
mitochondrion’s electron-
transport chain
Energy-converting metabolism in
mitochondria
o chemiosmotic coupling
Mitochondria have many essential roles in cellular metabolism:
o critical for buffering the redox potential in the cytosol
shuttle system for NADH electrons
pentose phosphate pathway is an alternative to glycolysis
o Two critical steps of the urea cycle are carried out In the mitochondria of liver
cells, while the remaining steps occur in the cytosol
o play essential part in the metabolic adaptation of cells to different nutritional
conditions
o biosynthesis of heme groups
o iron-sulfer clusters are produced in mitochondria
o have central role in membrane biosynthesis
o major source of phospholipids for the biogenesis of other cell membranes
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller esmstegeman. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.21. You're not tied to anything after your purchase.