OBJECTIVES Know: the structure of ATP Understand: how ATP can provide energy Be able to: briefly describe glycolysis, TCA and the Electron transfer chain. Exam Style Questions.

Learning Objectives Success Criteria Understand where glycolysis fits into the overall process of respiration Describe the main stages of glycolysis Describe the main products of glycolysis  Compare the key stages of aerobic and anaerobic respiration  Accurately describe the chemical reactions at each stage of glycolysis  Make a model of the chemical changes that occur in glycolysis

ATP (Adenosine triphosphate )  ATP broken down by hydrolysis (requires water)  Catalysed by ATPase  Breakdown products are ADP and free P group and energy  Energy released then used by body

Uses of ATP

Lactic Acid system  This is also referred to anaerobic glycolysis.  It can take place in the absence of oxygen.  This process involves the breakdown of carbohydrates  Is the 2nd fastest way to make ATP.  Takes place in the cytoplasm of muscle cells

Lactic Acid Cont.  Involves the partial breakdown of glucose or glycogen in the absence of O2  By-product of breakdown is pyruvic acid  If not enough O2 available to cell, pyruvic acid converted into lactic acid

Anaerobic glycolysis - simplified

Explanation of Diagram  1 molecule of glucose yields 2 molecules of pyruvic acid  Enough energy is released to re- synthesise 2 molecules of ATP

Glycolysis overview.  

AEROBIC SYSTEM  Second way to provide energy for ATP re-synthesis  Is the slowest method  But produces the most energy  Needs oxygen  Involves 4 stages in which glucose is eventually broken down into water and CO2

Four stages of aerobic glycolysis  Aerobic glycolysis  Activation of pyruvate to Acetyl CoA  TCA/citric acid/Krebs cycle  Electron transport/transfer chain

video 

Aerobic glycolysis  Is the same as anaerobic glycolysis  Production of pyruvic acid  Enough energy yield to re-synthesise 2 molecules of ATP  Pyruvic acid diffuses into matrix of mitochondria for next stage  Can take place without oxygen

Activation of pyruvate to Acetyl CoA  Activation of pyruvate to Acetyl CoA”  This drives the pyruvate molecule towards the TCA cycle in the mitochondrion  Two molecules of reduced Co-enzyme A are generated

VIDEO 

TCA/citric acid/Krebs cycle

Simplified Krebs cycle

Krebs cycle  CO2 is produced  Oxidation takes place (H atoms removed)  Sufficient energy is released to synthesise 2 molecules of ATP

VIDEO 

Stage 4-Electron Transport chain  H atoms produced during stage 2 are carried by coenzymes to cristae of mitochondria  Electrons removed from H atoms and are passed along by electron carriers  Eventually combine with O and H ions to from water  Energy yield from stage 3 enough to re-synthesise 34 molecules of ATP

Electron Transport chain

VIDEO 

QUESTIONS  Can you explain glycolysis and the TCA cycle?  Do you know how many Carbon atoms are involved at each stage?  What happens to the Hydrogen atoms that are released?  Where in the cell does glycolysis occur and where does the TCA cycle occur ?