aerobic resp

Aerobic Cellular

Respiration

http://www.astronomynotes.com/nature/spr06flowers/red/red3.jpg AND http://aqualandpetsplus.com/Live%20F222.jpg

Pea plants Zophobus morio larvae

I. Cellular Respiration (Intro)

• Cells require ATP in order to function.

• Cellular respiration is the “metabolic machinery that releases energy from food molecules”.

Organic compoundsFood

CarbohydratesProteins

Lipids

ATP(energy)

Oxidized

(Loose electrons in form of H atoms)

I. Cellular Respiration: Anaerobic vs. Aerobic

Anaerobic Respiration (ex. fermentation, lactic acid fermentation)

does not require oxygen for the production of ATP.

Aerobic Respiration requires oxygen for the

production of ATP.

Certain organisms can perform both Anaerobic and Aerobic respiration

depending on the availability of Oxygen.


Certain organisms can perform both Anaerobic and Aerobic respiration

depending on the availability of Oxygen.

Yeast Cells can perform aerobic respiration or alcoholic fermentation

Human Muscle Cells can perform aerobic respiration OR when starved for oxygen, as in during vigorous exercise, muscle cells can switch to producing ATP by lactic acid fermentation (cause of lactic acid buildup).

Yeast Cells, in the absence of oxygen can produce ATP by alcoholic fermentation.


glucose 2 CO2 + 2C2H5OH (ethanol) + 2 ATPenzymes

Human Muscle Cells, when starved for oxygen as in during vigorous exercise, can switch to producing ATP by lactic acid fermentation (cause of lactic acid buildup).

glucose 2 CO2 + 2C3H6O3 (lactic acid) + 2 ATPenzymes

II. Aerobic Respiration: Whole Organism

• Aerobic respiration at the whole organism level = process by which gases are exchanged with the environment.

O2

CO2


• Respiratory Surface (= part of the organism where O2 diffuses into and CO2 diffuses out of

the organism) must be moist, as gases must be dissolved in water before they can diffuse in or out.

http://www.go-epix.net/uploadedimages/Water%20drop%20ks16870%208050114134057.JPG


In unicellular aquatic protozoans: O2 dissolved in water passes across the cell membrane by diffusion, and CO2 exits.

O2

CO2


In multicellular aquatic plants and invertebrate animals: O2 dissolved in water enters cells by diffusion, and CO2 exits by diffusion.Elodea cell

O2 CO2

Planarian

http://www.cdb.riken.jp/jp/04_news/img/planarian300.jpg


In insects: O2 enters through small openings in the body wall (spiracles) and is carried through tracheal tubes to moist cell membranes, across which respiratory exchange occurs.

spiracle

Spiracles

SEM


In fish: O2 (in H2O) diffuses across the surface of gills, into capillaries of the circulatory system and CO2 diffuses in the opposite direction.


In terrestrial vertebrates: O2 diffuses across moist epithelial cells in the internal alveoli of the lungs. CO2 diffuses in the opposite direction.

O2

CO2


In multicellular terrestrial flowering plants: O2 (in H2O) diffuses across the surface of roots and stems, and CO2 diffuses in the opposite direction. Leaves possess specialized cells (guard cells) which open and close stomates, regulating gas exchange.

II. Aerobic Respiration: Cellular

• Cells of most organisms, including plants, carry out aerobic cellular respiration 24 hours per day.

C6H12O6 + 6O2 6CO2 + 6H2O + 36 ATP + HeatEnzymes

60% of energy from glucose is trapped in

ATP

40% of energy from glucose is lost as heat

Endothermic animals use this heat for regulating

body temperature

Glucose


To measure the rate of respiration one can either 1) measure the rate of reactants consumed, or 2) measure the rate of products produced.

C6H12O6 + 6O2 6CO2 + 6H2O + 36 ATP + HeatEnzymes

products producedreactants consumed

In lab you will be measuring the rate of reactants consumed.


1

Glycolysis


1

– enzyme catalyzed– energy releasing– takes place in cell cytoplasm

(prokaryotic and eukaryotic cells)C6H12O6 2 Pyruvic acid molecules + 2 NADH + 2 ATP

Glycolysis


1

Glycolysis


2

Preparation step


1

– occurs in fluid matrix of mitochondria (eukaryotic organisms)

2 Pyruvic acid mols CO2 + NADH + 2 Carbon compounds

Preparation step


2

Preparation step


3

Kreb’s Cycle


1

– enzyme catalyzed– occurs in fluid matrix of mitochondria

(eukaryotic organisms)

2 Carbon Compound CO2 + ATP + FADH2 + NADHAcetyls

Kreb’s Cycle


3

Kreb’s Cycle


E- transport and Chemiosmosis4


1

– electrons from NADH and FADH2 pass through a series of compounds and loose energy.

– some energy is lost as heat– most of the energy is trapped at ATP through

the process of chemiosmosis– occurs in cristae of the mitochondria

(eukaryotes) or folds of the cell membrane (prokaryotes).

E- transport and Chemiosmosis

O2 is the final acceptor of electrons that were originally part of the glucose molecule. O2 combines with the electrons and H+ to form water.


E- transport and Chemiosmosis4

Stage Site Within Cell Overall process Number of ATP molecules produced

Glycolysis Cytosol Glucose is split into 2 molecules of pyruvate

2 per glucose molecule

Pyruvate Oxidation

Matrix – inner fluid of mitochondria

Pyruvate is converted to acetyl co A

none

Krebs Cycle Acetyl co A drives a cycle of reactions to produce hydrogen

2 per turn so 4 per glucose

Electron Transport Chain

Inner membrane of mitochondria

Hydrogen drives a series of redox reactions to produce ATP

Up to 32 per glucose

Criteria Aerobic respiration

Anaerobic respiration

Organism Mostly living cell Bacteria, yeast, muscle cells

Oxygen present Present Absent or limited

Glucose breakdown

Complete Incomplete

Place of glucose breakdown

Cytoplasm and mitochondrion

Cytoplasm only

Yield Carbon dioxide, water, energy

Ethanol, carbon dioxide, energy, lactic acid

Total energy High (38 ATP) Low (2 ATP)

aerobic resp

Documents

organism aerobic respiration

rate of respiration

cellular cells

co2 o2

cellular glycolysis1

production of atp

atp human muscle cells

cellular preparation