Respiration

Respiration is using food to release energy

How is energy used?

building large molecules from smaller ones

the active transport of substances within the body

maintaining a steady body temperature

muscle contraction

Types of Respiration

Aerobic Respiration – the release of energy from food using oxygen

Anaerobic Respiration- The release of energy from food without using oxygen

Anaerobic respiration

It is also called Fermentation

There is only 1 stage

Two types:1.Lactic Acid Fermentation2.Alcohol Fermentation

Lactic Acid Fermentation

Lactic acid is produced

Happens in some bacteria and fungi Example bacteria anaerobically respire in

milk and make lactic acid which sours the milk

Happens in animal muscles when there is not enough oxygen example - during exercise. The lactic acid causes cramps!

Alcohol Fermentation

alcohol and carbon dioxide are made

Takes place in Bacteria and some fungi such as yeast

Example - Yeast respires anaerobically in bread.... the alcohol evaporates but the carbon dioxide causes the dough to rise

Happens in plants ( if there’s not enough oxygen)

Investigation: To show the production of alcohol by anaerobic

respiration in yeast

Testing for presence of alcohol..

Step 6

Filter the contents of each flask into separate boiling tubes.

Step 7 and 8

Add 3 ml potassium iodide to each boiling tube.

Add 5 ml sodium hypochlorite to each boiling tube.

Step 8

Add 5 ml sodium hypochlorite to each boiling tube.

Step 9

Place boiling tubes in a water bath at 60°C for 4-5 minutes.

Expected result

Biotechnology

Biotechnology is when living cells (or parts of them) are used to manufacture useful products.

It is mostly microorganisms or enzymes that are used.

Examples of microorganisms used in bioprocessing

Bacteria can be used to make the lactic acid, which is needed in yoghurt production

In alcohol fermentation yeasts are used to make beer and wine and also carbon dioxide for baking

Industrial Fermentation

The microorganisms are placed in a bioreactor with a suitable substrate on which they can react

Oxygen is pumped in through a sparger

A foam breaker to stop the build up of foam

Product out here

Substrate and microorganisms in here

Industrial fermentation

Quality and amount of product depend on: the quality of the microorganism and

substrate, the design of the bioreactor, a correct rate of mixing, a correct temperature and pH elimination of contaminating microorganisms

Learning Check

What is biotechnology?What is a bioreactor?Why is a foam breaker needed?What is oxygen pumped in through?Name a few factors that affect quality and

amount of productWhat types of microorganisms are used in

bioprocessing?

Bioprocessing with Immobilised cells

To ensure the microorganisms used in a bioreactor are not lost at the end of every reaction they are often immobilised or fixed

The microorganisms can be immobilised by bonding them to each other or an inert substance

Immobilised Cells are used in alcohol production

In alcohol fermentation the yeast cells are immobilised by mixing them with sodium alginate and calcium chloride to make beads of material.

Alcohol and carbon dioxide

Glucose

Advantages of Immobilised Cells

1. It is a gentle procedure so does not damage cells.

Immobilised cells:2. can be reused

3. can be easily recovered.

4. reduce the need for filtration at the end of bioprocessing

Uses of Immobilised Cells

Immobilised cells are becoming more popular than immobilised enzymes as it saves time isolating and purifying enzymes which is an expensive process!

Equation for Aerobic Respiration

C6H12O6 + 6O2 6CO2 + 6H2O + Energy

Glucose + Oxygen Carbon dioxide + water + energy

Aerobic respiration

Aerobic Respiration occurs in 2 stages

Stage 1 Stage 2

Mitochondrion

Cytoplasm

Cell membrane

Nuclear membrane

Chromatin

Nuclear pore

Ribosome

Stage 1

Takes place in the cytosol (the part of the cytoplasm without the organelles).

Does not require oxygen

Small amounts of energy released

(This stage happens in both aerobic and an aerobic respiration)

Mitochondrion

Cytoplasm

Cell membrane

Nuclear membrane

Chromatin

Nuclear pore

Ribosome

Stage 2

Uses oxygen

Large amount of energy released

It occurs in the mitochondria

(This stage only happens in aerobic respiration)

Mitochondria

Aerobic AnaerobicLocation in cell Cytosol and

mitochondria Cytosol

Oxygen Requirements

Uses O2 Does not use O2

End Products CO2 + H2O Ethanol +CO2

or

Lactic acid

Energy Produced Lots of energy

Little energy

Differences between Aerobic and Anaerobic Respiration

Respiration extended study HL

Energy carriers

•There are special molecules in our cells, such as ATP that act as energy carriers

ADP and ATP

ADP stands for Adenosine DiPhosphate

ADP is a low energy molecule

ADP and ATP

If another phosphate is added to ADP it forms ATP (Adenosine Triphosphate)

Adding a phosphate is called phosphorylation

ADP + P+ energy ATP+H2O

+H2O

Function of ATP

• ATP is rich in energy • The function of ATP is to

trap and transfer energy needed for cell activities

ADP and ATP

ATP cannot store energy for very long - it breaks down releasing energy and converting back to ADP

ATP+H2O ADP +P +energyThis energy is used for cellular reactions

H2O+

Happens in the cytosol

6-carbon Glucose is converted to two 3 carbons molecules of pyruvate

A small amount of ATP is MADE

No oxygen is needed

Stage 1 – called Glycolysis

What happens next….

In anaerobic respiration the pyruvate molecules will be converted to:

Lactic acidOr

Alcohol and carbon dioxide

In aerobic respiration the pyruvate molecules go through to the second stage in respiration

Stage 2 only happens in aerobic respiration

Each pyruvate enters a mitochondrion

Each Pyruvate is broken down to aa carbon dioxide molecule and a 2-carbon molecule called Acetyl coenzyme A (Acetyl CoA for short)

Stage 2 – Krebs cycle

The Acetyl CoA enters a series of reactions called Kreb’s cycle

As the acetyl CoA is broken down carbon dioxide and electrons are released.

These electrons are passed along to species which accept the electrons and then pass them along “substrate intermediates”

We say that these electrons are passed along an electron transport chain. As this happens energy is released and is used to make lots of ATP.

Kreb’s Cycle

Krebs cycle

At the end of the cycle the electrons eventually are accepted by oxygen and this then combines with hydrogen to form water.