Cellular RespirationCellular Respiration

AP BiologyAP Biology

Why do we need Cellular Why do we need Cellular Respiration?Respiration?

If we released all of the If we released all of the energy from glucose all at energy from glucose all at once (transfer electrons once (transfer electrons

directly to oxygen), so much directly to oxygen), so much heat would be released that heat would be released that we would explode or at least we would explode or at least denature all of our proteins.denature all of our proteins.

Cellular Respiration OverviewCellular Respiration Overview

Taking the high energy electrons out of Taking the high energy electrons out of sugar and releasing the energy from sugar and releasing the energy from

the electrons in small steps, the electrons in small steps, eventually returning the electrons and eventually returning the electrons and protons (H+) to oxygen making water protons (H+) to oxygen making water

AND making ATP using the energy AND making ATP using the energy released from the electronsreleased from the electrons

ATPATP

ADPADP

ATPATP

Release EnergyRelease Energy

To do workTo do work

From glucoseglucose

Use Energy in ATP to do workUse Energy in ATP to do work

Work in living things:Work in living things: TransportTransport

Chemical reactionsChemical reactions

Muscle ContractionMuscle Contraction

Active Transport, Endo and ExocytosisActive Transport, Endo and Exocytosis

Mitochondria StructureMitochondria Structure

Enzymes (Krebs), DNA, RNA, ribosomes

e.t.c.e.t.c.

Making ATPMaking ATP

Oxidative Phosphorylation: Oxidative Phosphorylation: Phosphorylating ADP as the result of the Phosphorylating ADP as the result of the e.t.c. in the mitochondria (chemiosmosis)e.t.c. in the mitochondria (chemiosmosis)

Substrate Level Phosphorylation:Substrate Level Phosphorylation:

An enzymatic transfer of Phosphate onto An enzymatic transfer of Phosphate onto another molecule (usually ATP)another molecule (usually ATP)

Overview of the reactionsOverview of the reactions

Overview of the reactionsOverview of the reactions

Glycolysis

Cytoplasm

Anaerobic

With oxygen

Chemical reaction to make Chemical reaction to make acetateacetate (mitochontrial (mitochontrial matrix)matrix)

Krebs cycleKrebs cycle (mitochondrial (mitochondrial matrix)matrix)

Electron Transport ChainElectron Transport Chain (inner-mitochondrial (inner-mitochondrial membrane)membrane)

Aerobic

FermentationFermentation

Cytoplasm

Still Anaerobic

Without oxygen

ATPATP238

GlycolysisGlycolysis: first step of : first step of cellular respirationcellular respiration

GlucoseGlucose

Pyruvate PyruvatePyruvate Pyruvate

2 ATP 2 ATP (substrate level phosphorylation)(substrate level phosphorylation)

2 carriers with H+ and 2 carriers with H+ and high energy electronshigh energy electrons

(NADH)(NADH)

No Name StepNo Name Step (first step in (first step in mitochondrial matrix – aerobic)mitochondrial matrix – aerobic)

Pyruvate AcetatePyruvate Acetate

CO2 released and H CO2 released and H with its high energy with its high energy

electrons get put on a electrons get put on a carrier (NAD+)carrier (NAD+)

+ Coenzyme + Coenzyme AA

Acetyl CoAAcetyl CoA

The Kreb’s Cycle (The Citric Acid The Kreb’s Cycle (The Citric Acid Cycle):Cycle):

Series of Chemical Reactions in Series of Chemical Reactions in Mitochondrial MatrixMitochondrial Matrix

Acetate gets broken down to 2 CO2 andAcetate gets broken down to 2 CO2 andall 4 of the H with their high ENERGY all 4 of the H with their high ENERGY

electrons get put onto carrierselectrons get put onto carriers

2 ATP’s are made (substrate level)2 ATP’s are made (substrate level)

For each glucose, there are 2 acetates!For each glucose, there are 2 acetates!

Krebs CycleKrebs Cycle

Electron Transport ChainElectron Transport ChainLocated in the inner membraneLocated in the inner membrane

Electron Transport Chain – series of Electron Transport Chain – series of carriers – each one more electronegative carriers – each one more electronegative (attracted to electrons) than the previous (attracted to electrons) than the previous oneoneAs the electrons are passed from carrier to As the electrons are passed from carrier to carrier – they are pulled closer to the carrier – they are pulled closer to the atomic nucleus which causes them to lose atomic nucleus which causes them to lose energyenergyThe energy is lost a little bit at a timeThe energy is lost a little bit at a time

The Electron Transport ChainThe Electron Transport Chain

Steps of the Steps of the E.T.CE.T.C. . STEP 1: the electron carriers that picked up electrons in STEP 1: the electron carriers that picked up electrons in glycolysis, no name step, and the Kreb’s cycle pass their glycolysis, no name step, and the Kreb’s cycle pass their electrons to the first molecule of the electron transport electrons to the first molecule of the electron transport chainchainSTEP 2: with each successive pass to other carriers, STEP 2: with each successive pass to other carriers, the electronsthe electrons lose energylose energy STEP 3: The energy lost by the electrons is used to STEP 3: The energy lost by the electrons is used to makemake ATP’s (34/ glucose) by chemiosmosisATP’s (34/ glucose) by chemiosmosisSTEP 4: The Hydrogens and their electrons which now STEP 4: The Hydrogens and their electrons which now have the normal amount of energy (lost the extra have the normal amount of energy (lost the extra absorbed by the sun during the e.t.c) combine with absorbed by the sun during the e.t.c) combine with oxygen to form water. There isn’t a big energy change oxygen to form water. There isn’t a big energy change all at once so there is no explosion just the loss of a all at once so there is no explosion just the loss of a reasonable amount of heatreasonable amount of heat

SummarySummary

Break the sugar apart back into CO2 and H Break the sugar apart back into CO2 and H which combine with O to make H2Owhich combine with O to make H2O

The excess energy stored in the electrons of H The excess energy stored in the electrons of H is slowly released and used to make ATP before is slowly released and used to make ATP before they combine with the Othey combine with the O

Therefore, the energy that came from the sun Therefore, the energy that came from the sun and was stored in the organic molecule sugar, is and was stored in the organic molecule sugar, is now temporarily stored in ATP until the energy is now temporarily stored in ATP until the energy is used to transfer the last phosphate to a motor used to transfer the last phosphate to a motor protein, muscle protein, active transport channel, protein, muscle protein, active transport channel, or substrate to do workor substrate to do work

FermentationFermentationPyruvates + NADHPyruvates + NADH

(2 of them)(2 of them)

Alcohol + Alcohol + CO2 + CO2 + NADNAD++

Lactic Lactic Acid + Acid +

NAD+NAD+

Animal CellAnimal CellYeast CellYeast Cell

All are waste products, so most of the energy All are waste products, so most of the energy stored in the sugar ends up not getting used by stored in the sugar ends up not getting used by

the organismthe organism

Purpose is regenerate the NAD+Purpose is regenerate the NAD+

Anerobic ActivitiesAnerobic ActivitiesNo activity can be totally anaerobic and be No activity can be totally anaerobic and be compatible with life – it just means you compatible with life – it just means you can’t get enough Oxygen to stay totally can’t get enough Oxygen to stay totally aerobic (your need for ATP is greater than aerobic (your need for ATP is greater than you can supply the oxygen for)you can supply the oxygen for)Anaerobic activities include anything that Anaerobic activities include anything that makes you breathe excessively heavy – makes you breathe excessively heavy – sign you’re not getting enough oxygensign you’re not getting enough oxygenSprinting, swimming really fast, biking Sprinting, swimming really fast, biking really fast, etc., lifting really heavy weightsreally fast, etc., lifting really heavy weightsYou will make lactic acid and run out of You will make lactic acid and run out of ATP – can’t keep going for very longATP – can’t keep going for very long

Making Wine and BreadMaking Wine and Bread

Yeast using the sugar provided by grapes or Yeast using the sugar provided by grapes or flour and added sugar to do cellular respirationflour and added sugar to do cellular respiration

Sugar diffuses into yeast cells, if not enough Sugar diffuses into yeast cells, if not enough oxygen, do some aerobic and some anaerobic oxygen, do some aerobic and some anaerobic respirationrespiration

As a result of anaerobic, they make alcohol and As a result of anaerobic, they make alcohol and CO2CO2

In wine, CO2 evaporates and left with alcohol in In wine, CO2 evaporates and left with alcohol in the grape juicethe grape juice

In bread, baking the bread makes the CO2 and In bread, baking the bread makes the CO2 and alcohol evaporate leaving behind holes where alcohol evaporate leaving behind holes where CO2 was making the bread fluffyCO2 was making the bread fluffy

How to use Fat and Protein for How to use Fat and Protein for EnergyEnergy

Each fatty acid is broken up and Each fatty acid is broken up and rearranged to form many acetates which rearranged to form many acetates which enter the Kreb’s Cycleenter the Kreb’s Cycle

Amino acids contain very few C-H bonds Amino acids contain very few C-H bonds but the amino and acid groups can be but the amino and acid groups can be clipped off, and the rest can also be clipped off, and the rest can also be rearranged to enter glycolysis or the rearranged to enter glycolysis or the Kreb’s CycleKreb’s Cycle