Cellular Respiration

Cellular Respiration and Breathing Aerobic process – requires oxygen. Cellular Respiration – exchange of oxygen and carbon dioxide between a cell and its environment Breathing – exchange of oxygen and carbon dioxide between your blood and the outside air.

Cellular Respiration Purpose: Generate ATP for cellular work 38 ATPs made per glucose molecule

Electron Transport Chain During Respiration glucose is broken down in several steps. Molecules (electron carriers) accept electrons from glucose and pass them to other carriers (electron transport chain). In each transfer the electrons release a little energy, which is trapped to make ATP.

Electron Transport Chain (cont’d) Oxygen is the final electron acceptor. It takes the electrons and joins them with hydrogen ions to form water.

Cellular Respiration

Structure of Mitochondria Double membrane envelope with space in between. Inner membrane is highly folded and encloses a fluid filled space called the Matrix. Complex folding allows for sites where reactions can occur to make ATP.

Mitochondria

Article What type of process is glycolysis? A. aerobic B. anaerobic

Your muscles use the most energy... A. At rest B. During aerobic activity C. During anaerobic acitivity

A by-product of cellular respiration is: A. Oxygen B. Carbon Dioxide C. Glucose

Stage 1: Glycolysis Breaking down a glucose molecule Takes place in the cytoplasm

Stage 1: Glycolysis Input: 2 ATP molecules, Glucose Output: 4 ATP molecules, 2 pyruvic acid molecules & 2 NADH molecules

Stage 2: The Krebs Cycle Finishes the breakdown of pyruvic acid to carbon dioxide, releasing more energy. Takes place in matrix of the inner membrane of mitochondria.

Stage 2: The Krebs Cycle Input: 2 Pyruvic Acids (from 1 glucose) Output: 2 ATP molecules, 4 carbon dioxide molecules.

What is the final net gain of ATP molecules in the first stage, glycolysis? A. 4 B. 6 C. 2 D. 1

How many ATP molecules were made in the second stage, the Krebs cycle for one glucose molecule? A. 1 B. 2 C. 3 D. 4

Stage 3: Electron Transport Chain and ATP Synthase Action Occurs in the inner membrane of the mitochondria. 2 Part Process

Part 1 NADH transfers electrons from glucose to transports chain. Electrons move down the transport chain, releasing energy which is used to pump hydrogen atoms across the membrane from an area of low to high concentration.

Part 2 Hydrogen atoms flow back through ATP synthases (protein structures in mitochondria) to the outside of the mitochondria. ATP synthase uses the energy from the hydrogen flow to convert ADP to ATP. (34 ATPs/glucose molecule)

How many ATP molecules were made in the third stage, the electron transport chain? A. 4 B. 2 C. 34 D. 38

From Kreb’s From Glycolysis From Acetyl Formation FADH 2 NADH Electrons Flowing (e-) H 2 O (made) (2 electrons needed) O 2 (consumed) H+ (pumped in) ATP (produced) DO NOW: COPY THIS CHART!!!!

Notes For every 1 electron moving across a pump, one H+ ion is pumped in. For every NADH, 6 H+ ions are pumped into the mitochondria. For every FADH, 4 H+ ions are pumped in

Notes Total H+ = (# of electrons flowing) X (# of pumps) For every 2 H+ ions moving through ATP synthase, 1 ATP is formed.

COPY THIS SUMMARY For every 1 electron moving across a pump, one H+ ion is pumped in. Each NADH and FADH 2 holds 2 electrons. Total H+ = (# of electrons flowing) X (# of pumps) For every 2 H+ ions moving through ATP synthase, 1 ATP is formed.

If 3 NADH’s flow across 3 pumps how many H+ ions enter the mitochondria? How many ATPs are formed?