Do now – make sure the following terms are in your glossary Turgid Flaccid Facilitated diffusion Vesicle Endocytosis Exocytosis

Cellular Respiration

Introduction to Respiration SLOs

Describe the key component/ terminology used in respiration what each molecule does ATP – energy carrier (analogy with money) NADH – carries hydrogen atoms Glucose Acetyl CoA Pyruvate Krebs Cycle Electron transport system

Give the overall word and chemical equation for the respiration reaction

State the reactants and products in respiration

RespirationRespiration = conversion of chemical

energy in organic compounds into energy that can be used by the cell.

Large food molecules are broken down to release energy. I.e. Glucose is broken down via a series of enzyme reactions.

ATP (Adenosine triphosphate) is the end-product of cellular respiration

Respiration Equation

Glucose + oxygen energy + carbon dioxide + water

C6H12O6 + O2 CO2 + H2O + energy

ATP (Adenosine triphosphate) ATP is the energy carrier in cells. It diffuses

through cells and is used for all energy-consuming processes in the cell

ATP exists in three forms, you only need to know two of these forms:

- ATP = high energy form, energy carrier - ADP (adenosine diphosphate) = the “empty”

energy carrier

Role-playing demo

ATP (continued)

ATP ↔ ADP + Phosphate + energy

OR

Adenosine-P-P-P

Adenosine-P-P + energy + P

ATP (continued) ATP loses a phosphate when it gives up its

energy, and becomes ADP ADP has to return to the cytoplasm and the

mitochondria to be recharged with energy by the process of respiration

The conversion of ATP to ADP + Pi and the reverse reaction is called the ATP/ADP cycle.

The ATP/ADP cycle provides cells with energy for cellular activity.

The ATP/ADP cycle

Overall equation for Respiration

6O2 + C6H12O6 + 38 ADP + 38 P

enzymes

6CO2 + 6H2O + 38 ATP

ATP song (to the tune of the Beatles "Yesterday") ATP, active transport needs you, can't you see?

Sodium pumps require energy to go against the gradient.Cilia and flagella depend on you, not to mention pinocytosis to

internalize small molecules. Sometimes when water needs to be pumped out of a cell,

That's when contractile vacuoles make it seem more iso-to-o-o-nic.

ATP, the triphosphate of adenosine; ribose has five carbons in between.

Three phosphates and an adenosine. Glucose finds its way through the carrier molecules;

Those are proteins which are embedded in the cell membrane. Suddenly, turgor pressure builds up in a leaf

When water rushes into the hypertonic plant cellsWithout the help of ATP.

Types of Respiration Aerobic respiration: respiration occur in

presence of oxygen

Anaerobic respiration: respiration occur in absence of oxygen

(anaerobic = “without air”)

Burning paper demo

NAD – the hydrogen carrier Hydrogen contains most of the energy that

charges up ADP to ATP. The hydrogen comes from the breakdown of

glucose during respiration. The hydrogen is carried around by the carrier

nicotinamide adenine dinucleotide (NAD) When it is ‘full’ it is NADH2

Do Now – try to do this without looking at your notes!

1. Give the word and symbol equations for cellular respiration

Glucose + oxygen energy + carbon dioxide + water

C6H12O6 + O2 CO2 + H2O + energy2. Name the two forms of ATP – which is the high

energy form?ATP – adenosine triphosphate (high energy form)ADP – adenosine diphosphate (energy carrier)

3 Stages of respiration

1. Glycolysis2. The Krebs cycle (citric acid cycle)3. The respiratory chain (electron transport

system)

[Sometimes the formation of acetyl coenzyme A is included a separate step – see p68]

1. Glycolysis Glycolysis = “glucose-splitting” Both aerobic and anaerobic respiration

begin with glycolysis Takes place in the cytoplasm Glucose (6C) is broken down into pyruvate

(3C) molecules and 2ATP (net gain) 2 NADH2 carry hydrogen to the electron

transport chain

The Krebs cycle

Can only occur in the presence of O2 (aerobic only)

The pyruvate produced from glycolysis diffuses into the matrix of the mitochondria [matrix = space enclosed by the inner mem.], where they enter the Krebs cycle.

Pyruvate reacts with a molecule called coenzyme A, and forms acetyl coenzyme A

Pyruvate acetyl coenzyme A (acetyl coA) + CO2

The Krebs Cycle (continued) Acetyl group in acetyl coA is broken down to

CO2, H atoms, and ATP in the Krebs cycle. Coenzyme A is not broken down and return to pick up another acetyl group

i.e. Pyruvate Acetyl CoA

Acetyl group ATP + CO2 (waste) + H+

The Krebs cycle (continued)

The Respiratory Chain Most of the ATP is made in this step Takes place on the inner membrane of the

mitochondrion (cristae) Also aerobic (needed to oxidise hydrogen to

water) Uses the hydrogen produced in the Krebs

cycle. A chain of reaction results in the release of ATP.

High energy electrons are produced by the hydrogen (from Krebs cycle)

The Respiratory Chain (continued) – Advance The electrons are passed along the

respiratory chain, losing their energy to H+ pumps across the cristae (folding of the inner mito. mem.)

The H+ ions move back across the cristae after the electron has passed along the respiratory chain, providing energy for ATP production.

Oxygen is used to oxidise hydrogen to water

Yield of energy:Glycolysis = 2 ATPKrebs Cycle = 2ATPElectron transport = 34 ATPTotal = 34 ATP

Summary

Brainpop Cellular respirationhttp://www.brainpop.com/science/cellularlifeandgenetics/cellularrespiration/

321 REQ

Anaerobic respiration If oxygen is absent, pyruvate remain in the

cytoplasm and is broken down into: Lactic acid + energy in animals Ethyl alcohol + carbon dioxide + energy in

plants (fermentation)

Lactic acid = poison (but can be take away when oxygen is available)

Fermentation: only 2 ATP is produced (vs. 38 ATP in aerobic respiration)

Factors Affecting the rate of respiration

Rate of respiration = how rapidly glucose is broken down to produce energy

Rate of respiration depends on:1. The amount of oxygen present in cells2. The amount of glucose or fat present in the

cell3. The cell or body’s demand for energy4. Temperature – higher the temp., the greater

the rate of respiration