Photosynthesis and Cellular Respiration CH 7 Cellular Respiration

Photosynthesis and Cellular Respiration CH 7: Cellular Respiration pg 131 Section 3

Photosynthesis and Cellular Respiration Section 3 Cellular Respiration • All living organisms go through cellular respiration. – Series of chemical reactions to make ATP from glucose Equation for Photosynthesis • 6 CO 2 + 6 H 2 O + pigment + sunlight C 6 H 12 O 6 + 6 O 2 Equation for Cellular Respiration • C 6 H 12 O 6 + O 2 6 CO 2 + 6 H 2 O + ENERGY (ATP)

Photosynthesis and Cellular Respiration Section 3 • There are 2 scenarios – Aerobic (with oxygen) – Anaerobic (without oxygen) • Anaerobic – Glycolysis (only method for some prokaryotes) • Occurs in cytoplasm • Fermentation allows for this process to keep going • 2 ATPs are made

Photosynthesis and Cellular Respiration Aerobic Respiration • Occurs in the mitochondria • Kreb’s cycle • Electron Transport Chain Section 3

Photosynthesis and Cellular Respiration Section 3 Glycolysis • Series of chemical reactions that take place in the cytoplasm and does not need oxygen to work. • In glycolysis, enzymes break down one of glucose into two pyruvate/pyruvic acid molecules. *Glue glycolysis illustration into notes

Photosynthesis and Cellular Respiration Glycolysis Section 3

Photosynthesis and Cellular Respiration Section 3 Glycolysis, pg 133 • Step 1, Breaking Down Glucose – Glucose is converted back into 2 - G 3 P (3 carbon molecule).

Photosynthesis and Cellular Respiration Section 3 Glycolysis • Step 2 and Step 3, NADH and Pyruvate – Each of the G 3 P go through a series of chemical reactions • Converted into Pyruvate (pyruvic acid) – 2 molecules NADH are created • Important because NADH are Hydrogen ion/proton and ecarriers

Photosynthesis and Cellular Respiration Section 3 Glycolysis produces 2 ATP • with O 2 it also produces 2 NADH, 2 Pyruvates

Photosynthesis and Cellular Respiration Section 3 Fermentation (anaerobic process) pg 134 • To make ATP during glycolysis, NAD+ is converted to NADH. – Organisms must recycle NAD+ to continue making ATP through glycolysis. • The process in which carbohydrates are broken down in the absence of oxygen is called fermentation. – Beneficial because it allows glycolysis to continue supplying a cell with ATP in anaerobic conditions.

Photosynthesis and Cellular Respiration Pathway Lactic Acid Fermentation Section 3 Reaction PYRUVIC ACID + NADH LACTIC ACID + NAD+ *occurs in muscle cells for short term energy production, also used in the production of foods ex. yogurt, Kim chi, sauerkraut Alcoholic Fermentation PYRUVIC ACID + NADH ALCOHOL+ CO 2 + NAD+ *occurs in yeast cells and is used in the production of beer, wine and bread

Photosynthesis and Cellular Respiration Two Types of Fermentation Section 3

Photosynthesis and Cellular Respiration illustration Section 3

Photosynthesis and Cellular Respiration Section 3 Aerobic Respiration • 1 st stage is the Krebs cycle – a series of reactions that produce electron carriers • (NADH and FADH 2) • 2 nd stage electron transport chain takes place in the inner membranes of mitochondria – ATP synthase are located here • Up to 36 ATP molecules can be produced from one glucose molecule in aerobic respiration.

Photosynthesis and Cellular Respiration Section 3 Kreb’s Cycle • Pyruvate (from glycolysis) is broken down and combined with other carbon compounds creating Co. A. – Releasing CO 2 – 2 ATP, 6 NADH, and 2 FADH 2

Photosynthesis and Cellular Respiration Section 3

Photosynthesis and Cellular Respiration Section 3 Electron Transport Chain • Takes place in the inner membranes of mitochondria – ATP synthase are located here • NADH and FADH 2 from the Krebs cycle – transfer energy in the form of e- and H+ into the electron transport chain. • e- are used to pump the H+ across the membrane to create a concentration gradient

Photosynthesis and Cellular Respiration Section 3 Electron Transport Chain ATP Production • Hydrogen ions diffuse through ATP synthase, providing energy to produce several ATP molecules from ADP.

Photosynthesis and Cellular Respiration Section 3

Photosynthesis and Cellular Respiration Section 3 The Role of Oxygen • At the end of ETC – the e- combines with an oxygen atom and two hydrogen ions to form two water molecules. • If oxygen is not present, – the electron transport chain stops, because hydrogen has no where to go. – the electron carriers are not recycled, so the Krebs cycle also stops

Photosynthesis and Cellular Respiration Section 3 Summary Cellular Respiration Reactants Products Location Gycolysis Glucose, 2 ATP 2 Pyruvates, 2 NADH, 4 (2) ATP Cytoplasm Krebs Cycle 2 Acetyl. Co. A (Co. A) CO 2, 6 NADH, Matrix of 2 FADH 2 , 2 ATP Mitochondria ETC 6 NADH, 2 FADH 2, O 2 34 ATP, H 2 O, 6 NAD, 2 FAD Inner Mitochondrial Membrane