CELLULAR RESPIRATION TOPIC 3.7 (core) and TOPIC 8.1 (HL)

CELLULAR RESPIRATION

TOPIC 3.7 (core) and TOPIC 8.1 (HL)

Topic 3.7 Cellular respirationObjectives

• Define cell respiration.• State that, in cell respiration, glucose in the cytoplasm is

broken down by glycolysis into pyruvate, with a small yield of ATP.

• Explain that, during anaerobic cell respiration, pyruvate can be converted in the cytoplasm into lactate, or ethanol and carbon dioxide, with no further yield of ATP.

• Explain that, during aerobic cell respiration, pyruvate can be broken down in the mitochondrion into carbon dioxide and water with a large yield of ATP.

• Which form of energy is used by living things?

Living things use chemical energy for their biological work.

• What is the main source of energy for the Earth?

SUN• How do living things get this energy?

What are the biological works which require energy?

- Synthesis of new biomolecules- Active transport- Cell division- Movement

• Energy can be converted from one form to another, but it is neither created nor destroyed.

• SUN plants organic molecules

ATP cellular activities

* All cells use ATP for their cellular activities.

photosynthesis

Cellular

respiration

• Organic molecules have chemical energy.

• 1gr carbohydrate 4.2 kcal

• 1gr protein 4.3 kcal

• 1gr lipid 9.3 kcal

• Why do lipids store more energy than other organic molecules?

Structure of ATP

1- Substrate level phosphorylation: is the production of ATP by the direct transfer and donation of phosphoryll group to ADP from a phosphorylated substrate.

2- Oxidaditive phoshorylation: production of ATP by redox reaction in the

presence of oxygen 3- Photophosphorylation: production of ATP by light energy.

4- Chemophosphorylation: production of ATP by oxidation of inorganic substances such as NO3, Fe2+

ATP PRODUCTION

GENERAL FORMULA OF CELLULAR RESPIRATION

Glucose

Pyruvic acid

fermentation Aerobic respirationin mitochondria

Ethanolİn yeast

Lactic acidin muscle cell

glyc

olys

is

GLYCOLYSIS• Series of reactions which are common in aerobic

reactions and anaerobic reactions. (all living cells do glycolytic reactions)

• Take place in cytoplasm.• During glycolysis 2 ATP are used and 4 ATP, 2

NADH2 (coenzyme), 2 H2O and 2 pyruvic acids are produced.

• ATP are produced by substrate level phosphorylation.

• At the end of the glycolysis 2 ATP are gained.

CITRIC ACID (KREBS) CYCLE

ELECTRON TRANSPORT CHAIN

• ETS is a group of protein that transfer electrons.

• Most of the ATPs are produced by oxidative phoshorylationin the ETS.

LACTIC ACID FERMENTATION

ETHYL ALCOHOL FERMENTATION

HL TOPIC 8.1:Cell respiration• State that oxidation involves the loss of electrons from an element, whereas reduction

involves a gain of electrons; and that oxidation frequently involves gaining oxygen or losing hydrogen, whereas reduction frequently involves losing oxygen or gaining hydrogen.

• Outline the process of glycolysis, including phosphorylation, lysis, oxidation and ATP formation.

• Draw and label a diagram showing the structure of a mitochondrion as seen in electron micrographs.

• Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen.

• Explain oxidative phosphorylation in terms of chemiosmosis.• Explain the relationship between the structure of the mitochondrion and its function.

HL-8.1.1

• Cellular respiration is an oxidation reduction (redox) rection.

REDOX REACTIONS IN CELLULAR RESPİRATİON

* In the living things oxidation means; H atoms leave organic molecules. At the same time H atoms take energy and electrons from the chemical bond between H and C atom of the organic compound.

*These H atoms bind with coenzymes (NAD and FAD). That means e and energy are transferred to coenzymes.

*NAD and FAD transfer e, H and energy to ETS which are used for oxidative phosphorylation.

• In the areobic and anaerobic reactions organic molecules (glucose) are oxidized (give electrons).

• Which molecules are reduced?

*In arebic respiration during glycolysis and Krebs cycle e are taken from glucose and transferred in the ETS. The last e acceptor is oxygen.

*In fermentation last e acceptor is pyruvic acid and acetaldehyde.

Redox reaction during glycolysis

Glucose

3C molec 3C molec

pyruvate pyruvate

Acetyl-Co AAcetyle Co-A

Krebs cycle Krebs cycle

ETS

2 ATP

2 ATP 2 ATP

2H

2H

2H

2H

2H

2H

2H

2H2H

2H2H

2H

Electron transport system (ETS)

• Chemiosmosis

Chemiosmosis• NADH+H+ supplies pair of H atoms to the first carrier in the chain,

with the NAD+ returning to the matrix.• The hydrogen atoms are split, to release two electrons, which pass

from carrier in the chain.• Energy is released as the e- pass from carrier to carrier, and three of

these use this energy to transfer protons (H+ ) across the inner membrane space.

• As electrons continue to flow along the chain and more and more protons are pumped across the inner mitochondrial space, a concentration of protons builds up. The proton gradient is the store for potential energy.

• To allow e- to continue to flow, they must be transferred to a terminal e acceptor at the end of the chain. In aerobic respiration it is Oxygen (02 ). When combines with hydrogen it forms water.

• Protons pass back to matrix through ATP synthase. As they move down the concentration gradient, energy is released and this energy is used to make ATP.