These notes have been written by a student who attained A* in Biology solely from these notes. these notes come straight from the textbook and condense the information you need perfectly
CELLULAR RESPIRATION
Glucose- hexose sugar produced in photosynthesis/ contains energy
absorbed from sunlight within its carbon-hydrogen bonds
-when bonds broken, energy is released which is used in ATP synthesis by
chemiosmosis.
Respiration- complex multi-step reaction pathway- releases energy to make
ATP
-occurs similarly in eukaryotes to prokaryotes except that prokaryotes have no
mitochondria so reactions happen on cell membranes
GLYCOLYSIS: (occurs in both aerobic and anaerobic)
-occurs in the cytoplasm of the cell- because glucose molecule too big to enter
mitochondria
-Glucose split into 2 smaller 3-carbon pyruvate molecules
, 1.PHOSPHORYLATION: 2 ATP molecules needed - 1 phosphate released from each of
these to form 2 ADP. phosphates attach to glucose to form hexose bisphosphate
2.LYSIS: molecule is unstable causing it to split to form 2 triose phosphate molecules
3.PHOSPHORYLATION: another phosphate added to each triose phosphate to form 2 triose
bisphosphate molecules. (phosphates come from free inorganic phosphate ions in cytoplasm
4.DEHYDROGENATION: the 2 triose bisphosphate molecules then oxidised by removal of
hydrogen atoms to form 2 pyruvate molecules. NAD enzymes accept these hydrogens-
become reduced forming 2 reduced NAD molecules.
- 4ADP molecules gain a phosphate each to form 4 ATP molecules - this is an
example of substrate level of phosphorylation- formation of ATP without involvement
of electron transport chain or ATP synthase
-2 ATP molecules used at beginning but 4 formed in the end= net yield is 2 ATP molecules
PRODUCTS OF GLYCOLYSIS:
-2x pyruvate
-net gain 2 ATP
-2x reduced NAD
18.2 LINK REACTION:
-Link reaction occurs in the matrix- pyruvate molecules small enough to enter mitochondria
1. Pyruvate enters the mitochondrial matrix by active transport via specific carrier
proteins.
2. Pyruvate then undergoes oxidative decarboxylation (CO2 removed) and
dehydrogenation
3. Co-enzyme NAD is reduced to form NADH (accepts H atoms)
4. Forms 2-carbon acetyl group which binds to coenzyme A forming acetyl coenzyme A
(acetyl CoA)
5. Acetyl CoA delivers acetyl group to next stage of aerobic respiration (krebs cycle).
-Reduced NAD will be used in oxidative phosphorylation to synthesise ATP.
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 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 ayeshamehta2004. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £3.79. You're not tied to anything after your purchase.
