RESPIRATION HONORS BIOLOGY

THE BIG PICTURE

ENERGY RELEASE: BIOLOGICAL OXIDATION Step by step release of stored chemical energy (held in bonds of glucose) by enzyme-controlled biological reactions Release of energy in two forms: body heat ATP

CHAPTER 9 Some ATP is made from the breakdown of glucose without using oxygen! In other words, there are some organisms that do not NEED oxygen! To release energy a little at a time, the cell takes glucose apart a little at a time through a series of chemical reactions

9.2 PRODUCING ATP WITHOUT OXYGEN GLYCOLYSIS *glyco (glucose) lysis (break apart) *breakdown of glucose to release energy *first step in glucose breakdown *occurs in the cytoplasm

GLUCOSE C 6 H Glycolysis happens in ALL cells Glycolysis does NOT need oxygen Glycolysis uses 2 ATP to get the process going…. Oxygen

GLYCOLYSIS Two ATP needed to begin:

GLYCOLYSIS Glucose is split into 2 molecules of PGAL each containing 3 carbons Each new molecule is called PGAL

GLYCOLYSIS

TWO PGALs CONTINUE BREAKING DOWN TWO NADHs ARE FORMED HERE TWO ATPs ARE MADE HERE

PGAL CONTINUES TO BREAK DOWN UNTIL PYRUVATE IS FORMED END PRODUCT: PYRUVATE

WHAT IS NADH? NAD+ COMBINES WITH A H+ AND IT’S ELECTRONS TO FORM NADH NADH ACTS AS AN ELECTRON CARRIER FOR HIGH ENERGY ELECTRONS

INPUT VS OUTPUT INPUT ONE GLUCOSE TWO ATPs TWO NAD+ OUTPUT TWO PYRUVATES (also called pyruvic acid) FOUR ATPs TWO NADHs NOTE: _____IC ACID = ______ATE FILL IN THE BLANKS!

SOOOOOOO…..HOW MUCH ATP? TWO TO START FOUR ARE MADE = NET OF TWO ATPs DURING GLYCOLYSIS

SUMMARY ANIMATION Cellular respiration animation

FERMENTATION Mechanism to get rid of electrons if oxygen is not available Usually need oxygen to take H off of NADH to form more NAD+ so that glycolysis will keep going If there is no NAD+ you can’t have glycolysis because there would not be anything to pick up the electrons release when PGAL is broken down to pyruvate (pyruvic acid)

ANAEROBIC RESPIRATION OTHERWISE KNOWN AS ‘FERMENTATION’ TWO TYPES LACTIC ACID (LACTATE) ETHYL ALCOHOL

ANAEROBIC RESPIRATION

LACTIC ACID FERMENTATION When ATP is needed but oxygen is not present, the pyruvic acid (_______) changes into lactic acid (_________) Answer to blanks: pyruvate & lactate Happens in muscle cells after strenuous exercise and an oxygen debt occurs which causes pain and fatigue Only happens if cells need more energy than can be produced by glycolysis and no oxygen is present

LACTATE FERMENTATION USES TWO NADH TO CHANGE PYRUVATE INTO LACTIC ACID

SUMMARY ANIMATION Cellular respiration animation

ALCOHOL FERMENTATION Occurs in yeast cells Pyruvic acid from glycolysis is converted to carbon dioxide and alcohol Used is bread, beer and wine production

ALCOHOL FERMENTATION 2

COMPARISON OF TWO TYPES

WHAT IS MISSING?