How are breathing and C.R. related?

How is energy created in a controlled manner? Oxygen acts as the final “e - acceptor” WHY? – Oxygen has a – charge – Attracts 2 + charged H +

Electron Transport Chain Driven by Oxygen (which is the electron acceptor) Instead of one quick release of a massive amount of energy (lost as light and heat) energy is released in small amounts

G ATP is converted to ADP by losing a phosphate giving off ENERGY.

Cellular respiration C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + ATP

What is metabolism? All of the cellular processes that occur within your body (breaking down or building up chemical compounds) Cellular respiration is a metabolic pathway because it is a long series of reactions that are carried out to complete a process. Where does most of the metabolic pathway of cellular respiration take place? – MITOCHONDRIA

3 stages of Cellular Respiration

STAGE 1: GLYCOLYSIS Energy investment stage because it uses an initial input of 2 ATP Creates 4 ATP Net gain of 2 ATP Sugar splitting stage because it splits 1 glucose molecule into 2 pyruvate 4 ATP - 2 ATP 2 ATP

Recap of Glycolysis Location – Cytoplasm Energy invested – 2 ATP Net gain of ATP – 2 ATP Starting material – Glucose Ending material – 2 pyruvates (pyruvic acid) Total # of NADH – 2 NADH

Stage 2: Krebs Cycle Pyruvate must be converted to acetyl CoA to enter Krebs by losing a CO 2 (paying toll) Since glucose splits into 2 pyruvate: each glucose molecule goes through the cycle 2 times 3 water molecules created per pyruvate 3 CO 2 per pyruvic acid

Quick Recap of the Kreb’s Cycle How many turns of the cylce per glucose? –2–2 Per turn # of each created – ATP 1 – FAHD 2 1 – NADH 1 in creating acetly CoA 3 per turn of Krebs Total energy molecules – 2 ATP – 2 FADH 2 – 8 NADH Byproducts include – 2 CO 2 per turn so 4 total CO 2 – 1 CO 2 creating acetyl CoA so total of 6 CO 2

Electron Transport Chain NADH = 3 ATP FADH 2 = 2 ATP Final e - acceptor

OVERALL NADH in glycolysis = 2 x 3 = 6 ATP NADH in Krebs = 4 x 2 turns = 8 x 3 = 24 ATP FADH 2 in Krebs = 1 x 2 turns = 2 x 2 = 4 ATP ATP in glycolysis = 2 ATP ATP in Krebs = 1 x 2 turns = 2 ATP TOTAL ATP = 38 ATP

Anaerobic Respiration Reactions do not require oxygen to proceed. When anaerobic respiration takes place in cells it is referred to as – Fermentation: energy production in a cell under aerobic conditions Sugar  alcohol Sugar  lactic acid

Alcohol Fermentation Powered from NADH created during Glycolysis The NAD + created in fermentation is used to fuel the process

Lactic acid fermentation Converts pyruvate into lactic acid. Occurs in muscle cells and bacteria. Fueled by the NAD + made during fermentation.