Mrs. Cook Biology

What is Cellular Respiration? The molecule of glucose that is produced by photosynthesis in plants will be used by plants and animals for cellular energy. The glucose molecule will be broken into smaller packets of energy known as ATP. The energy in the glucose molecule is found in the bonds between the carbon atoms. The majority of this process takes place in the mitochondria.

What is Cellular Respiration? Definition: The process that releases energy by breaking down glucose and other food molecules in the presence of oxygen. Equation: 6O 2 + C 6 H 12 O 6  6CO 2 + 6H 2 O + Energy (ATP & Heat)

Requires: oxygen, & a food molecule (such as glucose) Produces: carbon dioxide, water and energy

Stages: Glycolysis Production of Acetyl Co-A Krebs Cycle Electron Transport

Glycolysis (Sugar Splitting) – Definition: the process in which one molecule of glucose (a 6-carbon sugar) is broken in half, producing a 3-carbon compound and 2 molecules of pyruvic acid, – Produces energy, but it uses it too! Uses 2 ATP Produces 4 ATP Net Gain of 2 ATP molecules – Produces 2 NADH

Production of Acetyl Co-A Pyruvic Acid made in Glycolysis is broken down in a transition reaction between Gylcolysis and Kreb cycle. When the 1 st carbon bond is broken CO2 is released. Energy is also released to produce 1 NADH Acetyl Co-A, a 2 carbon molecule, is made.

The Krebs Cycle Is aerobic  requires oxygen! Also known as the Citric Acid Cycle Can be broken into 2 Main Parts: Citric Acid Production Energy Extraction Produces: CO2, 1 FADH2, 3 NADH, 2 ATP

Electron Transport Requires Oxygen The electron carries (NADH, FADH) from Gylcolysis and Krebs Cycle will now surrender their high-energy electrons to form 32 ATP molecules. Once the electrons return to their lower energy level they combine with the oxygen and protons (H + ) to form Water.

Totals Gycolysis Pyruvic Acid Kreb Cycle Electron Transport Chain 2- 3 CarbonCO2 CO2 H2O Pyruvic AcidAcetyl Co-A 1- FADH2 2 - NADH1- NADH 3- NADH 2- ATP 2- ATP 32 ATP TOTAL= 36 ATP H2O CO2

Totals – When there is oxygen, cellular respiration produces 36 ATP!!! – Wastes are water and carbon dioxide. – The cell is more efficient at using food than an engine is at burning gasoline! It uses 38% of total energy available in glucose during cellular respiration. – Other 62% is released as heat – #1 use for ATP is body heat – homeothermic – warm blooded!

Uses for ATP Building organic compounds: carbs, fats, proteins Active transport Muscle contraction Cell communication Cell Division….

What happens if there is no Oxygen Present? Oxygen is needed for cellular respiration to occur in all organisms. Without oxygen instead of 36 ATP, only 2 ATP will be produced!!

Fermentation When there is no oxygen, Glycolysis is followed by fermentation. Definition: releases energy from food molecules by producing ATP in the absence of oxygen!

Two Types: Alcoholic Fermentation forms ethyl alcohol and carbon dioxide as wastes yeasts and a few other microorganisms causes dough to rise Beer, wine

Lactic Acid Fermentation pyruvic acid changes into lactic acid occurs in muscles when the body cannot supply enough oxygen, causes muscle aches & cramps cheese, yogurt, buttermilk, and sour cream pickles, sauerkraut, and kimchi, soy sauce