Need to respire Respiration is required to generate heat energy as well as supply ATP for muscle contraction (movement) in animals. Respiration is required to generate ATP for movement of sucrose in mass flow hypothesis in plants. Respiration is required to generate ATP for mitosis for replication in bacteria.
Structure of ATP A T P P P P Adenine 3 phosphate groups ribose P P A D P 2 phosphate groups ribose Adenine
Cells need a supply of ATP molecules to act as an immediate energy source for many processes such as:
maintaining resting potential in neurones
cell division and growth
and most metabolic reactions
Mitochondria Greatly increases the surface area for attachment of enzymes For protein synthesis The outer membrane is permeable to small molecules such as sugars, salts and nucleotides The inner membrane is selectively permeable, which allows mitochondria to control the composition of the matrix Codes for protein Contains enzymes (proteins) ATP synthase
Anaerobic respiration in mammals versus yeast Mammals Yeast g lucose pyruvate lactic acid g lucose pyruvate ethanol + CO 2 Note: Some microorganisms can do both aerobic and anaerobic respiration and are called ‘facultative bacteria.’ Lactic acid fermentation is reversible if O2 becomes present. Lactic acid must be sent to the liver to break down, thus if it stays too long in the muscles, it will cause them to be ‘sore.’
glucose (C6) breaks down to 2 molecules of pyruvate (C3) . (Note that compounds that end in ”-ate" can be called ”-ic acid". For example, lactate is lactic acid and malate is malic acid.)
glycolysis occurs in the cytoplasm (cytosol)
does not require oxygen
Is the start to both aerobic and anaerobic respiration
a total of 2 ATPs are gained (4 are produced and 2 are used to start the process for a total net of 2)
Glycolysis Pyruvate will either become a part of aerobic or anaerobic respiration depending on whether oxygen is present.
Aerobic Respiration recovers about 40% of the energy in glucose- more efﬁcient than a modern car engine. Glycolysis recovers only about 3% of the energy stored in glucose; nevertheless for a long period much of the history of life was written by organisms that could perform only glycolysis. Many of the most successful organisms in existence are anaerobic and thus only achieve 3% efﬁciency. Nonetheless it was only after the evolution of the Krebs Cycle and Electron Transport Chain that respiration could achieve a level of efﬁciency capable of sustaining larger, and more complex, multicellular organisms.