Class notes
3.5.2 AQA A level Biology Respiration Notes
- Course
- Institution
- Book
Detailed notes covering A Level Biology Specification Reference 3.5.2 - Respiration
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
More summaries for
-
AQA A-level Biology - Full summary condensed notes of the A-level course
-
TOP BAND/A* AQA A Level Biology Synoptic Essay - The part played by the movement of substances across cell membranes in the functioning of different organs and organ systems
-
AQA A-Level Biology Unit 7 - Genetics, Populations, Evolution and Ecosystems (Handwritten Notes)
Seller
Follow
aamaalmalik
Content preview
3.5.2 Respiration- Photosynthesis transfers solar energy into chemical energy of carbohydrates such as glucose
- Glucose can’t be used directly by cells as a source of energy, instead they use ATP as
immediate energy source
- Formation of ATP from hydrolysis of glucose takes place in cellular respiration
o Aerobic respiration = requires oxygen and produces carbon dioxide, water and
much ATP and involves complete breakdown of glucose
o Anaerobic respiration = absence of oxygen and produces lactate (in animals) or
ethanol and carbon dioxide (in plants and fungi) but only little ATP and involves
incomplete breakdown of glucose
Process of aerobic respiration:
1. Glycolysis = splitting of 6C glucose into 2 3C pyruvate molecules
2. Link reaction = 3C pyruvate molecule enter series of reactions to form acetyl coenzyme A
(2C molecule)
3. Krebs cycle = introduction of acetyl coenzyme A into oxidation-reduction reactions cycle
yielding ATP and lots of reduced NAD and FAD
4. Oxidative phosphorylation = electrons and reduced NAD and FAD used to synthesise ATP
with water as by-product
, GLYCOLYSIS:
- First stage in aerobic and anaerobic respiration
- Occurs in cytoplasm – as glucose is too big or no transport proteins available
1) Phosphorylation of glucose glucose phosphate
o Glucose made more reactive by addition of two phosphate molecules
(phosphorylation) to be split into two
o Phosphate molecules from hydrolysis of 1 ATP 1 ADP + Pi provide energy to
activate glucose and lowers activation energy for enzyme-controlled reactions
2) Phosphorylation of glucose phosphate hexose bisphosphate
o Using phosphate from hydrolysis of 1 ATP 1 ADP + 1 Pi
3) Splitting of the phosphorylated glucose
o Each glucose molecules split into 2 3C molecules = triose phosphate
4) Oxidation of triose phosphate
o Hydrogen removed from each of 2 triose phosphate molecules and transferred to
hydrogen carrier molecule = NAD reduced NAD
5) Production of ATP
o Enzyme-controlled reactions convert each triose bisphosphate into 3C molecule =
pyruvate whilst 2 molecules of ATP are regenerated from ADP
Overall yield of one glucose molecule in glycolysis:
- +2 ATP molecules
- +2 reduced NAD molecules
- +2 pyruvate molecules
Glycolysis = indirect evolution evidence
- Enzymes for glycolytic pathway found in cytoplasm of
cells so no organelle or membrane required
- Doesn’t require oxygen
- Absence of oxygen = pyruvate converted to lactate or
ethanol in anaerobic respiration to re-oxidise NAD so
glycolysis continues
Anaerobic Respiration:
- In absence of oxygen, Krebs cycle nor electron transfer chain can continue as all FAD and
NAD will be reduced
- For continuation of glycolysis, products (pyruvate and hydrogen) must be constantly
removed
- Hydrogen must be released from reduced NAD to regenerate NAD
- NAD replenished by pyruvate molecule accepting hydrogen from reduced NAD
- Oxidised NAD produced can be used in further glycolysis
- Less ATP produced in anaerobic because lactate and ethanol isn’t completely respired so
energy not used to make ATP so still have chemical energy and there’s no oxygen which is
required in the further steps of respiration
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 aamaalmalik. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.86. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
82191 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now