bacterial cell – genetic information not contained within a nucleus

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Page 1: Bacterial cell – genetic information not contained within a nucleus

CELLS

Page 2: Bacterial cell – genetic information not contained within a nucleus
Page 3: Bacterial cell – genetic information not contained within a nucleus
Page 4: Bacterial cell – genetic information not contained within a nucleus

Bacterial cell – genetic

information not contained

within a nucleus

Page 5: Bacterial cell – genetic information not contained within a nucleus
Page 6: Bacterial cell – genetic information not contained within a nucleus
Page 7: Bacterial cell – genetic information not contained within a nucleus
Page 8: Bacterial cell – genetic information not contained within a nucleus

Diffusion is the net movement of particles

from a high concentration to a low

concentration down the concentration gradient until an equilibrium is

reached

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Page 10: Bacterial cell – genetic information not contained within a nucleus
Page 11: Bacterial cell – genetic information not contained within a nucleus

Cell

Tissue

Organ system

Organ

Page 12: Bacterial cell – genetic information not contained within a nucleus

Organs are made of tissues. The stomach is an organ that contains:

■ muscular tissue, to churn the contents■ glandular tissue, to produce digestive juices■ epithelial tissue, to cover the outside and the inside of the stomach.

Page 13: Bacterial cell – genetic information not contained within a nucleus

PLANTS

Page 14: Bacterial cell – genetic information not contained within a nucleus

Examples of plant tissues include:

• epidermal tissues, which cover the plant

• mesophyll, which carries out photosynthesis

• xylem and phloem, which transport substances around the plant

Page 15: Bacterial cell – genetic information not contained within a nucleus

FOOD (GLUCOSE) OXYGEN+WATERCARBON

DIOXIDE +

We know that plants make their own food from sunlight. They are the producers in the food chain. This is done in the green parts of the plant, e.g. upper surface of the leaves.

Made by photosynthesis and stored as

starch in leaves, roots, stems,

etc.

Taken in through holes in the leaves

as a gas in air

waste product exhaled

Taken in through

the roots from soil

With light and

chlorophyll

Page 16: Bacterial cell – genetic information not contained within a nucleus

LIMITING FACTORS?• LIGHT INTENSITY

• TEMPERATURE

• CARBON DIOXIDE

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Page 20: Bacterial cell – genetic information not contained within a nucleus

Paraffin lamps have traditionally been used in greenhouses. Their use increases the rate

of photosynthesis because as well as the

light generated from the lamps, the burning

paraffin produces heat and carbon dioxide too

The use of artificial light allows photosynthesis to continue beyond daylight hours. Bright lights also provide a higher-than-normal light intensity.

The use of artificial heating allows photosynthesis to continue at an increased

rate.

Page 21: Bacterial cell – genetic information not contained within a nucleus

GLUCOSE

Converted into insoluble starch

for storage

Used in respiration

To produce fats and oils for storage

To produce proteins

To produce cellulose for cell walls

To produce proteins, plants also use nitrate ions that are absorbed from the soil.

Page 22: Bacterial cell – genetic information not contained within a nucleus

DISTRIBUTIONOF

ORGANISMS

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ENZYMES

Page 27: Bacterial cell – genetic information not contained within a nucleus

• Proteins act as:– structural components of tissues such as

muscles– hormones– antibodies– catalysts

• Catalysts increase the rate of chemical reactions. Biological catalysts are called enzymes. Enzymes are proteins.

Page 28: Bacterial cell – genetic information not contained within a nucleus

Enzymes are protein molecules, and so are made up of long chains of amino acids. Most enzymes contain between 100 and 1,000 amino acids.

These long chains are folded to produce a unique 3D shape which enables other molecules to fit into the protein.

Page 29: Bacterial cell – genetic information not contained within a nucleus

• The shape of an enzyme is vital for the enzyme’s function. High temperatures change the shape. Different enzymes work best at different pH values.

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Page 31: Bacterial cell – genetic information not contained within a nucleus

This is what happens at the active site

enzyme

reactant

+enzyme-reactant

complex↔products

enzyme

+↔

+ ↔ ↔ +

Page 32: Bacterial cell – genetic information not contained within a nucleus

If the temperature and pH changes sufficiently beyond an enzyme’s optimum, the shape of the enzyme irreversibly changes.

normal denatured

heat

pH

This affects the shape of the active site and means that the enzyme will no longer work.

When this happens the enzyme is denatured.

Page 33: Bacterial cell – genetic information not contained within a nucleus

Effect of pH…

A change in the pH changes the shape of the protein molecule, the enzyme loses its active site and so can no longer act as a catalyst.

Page 34: Bacterial cell – genetic information not contained within a nucleus

Effect of temperature…

Page 35: Bacterial cell – genetic information not contained within a nucleus

QUIZ!1. What are biological catalysts called?2. What are enzymes made of?3. What is the place on the enzyme

where the reactant molecule binds called?

4. What does it mean when an enzyme is denatured?

5. What two factors can affect enzyme action?

Page 36: Bacterial cell – genetic information not contained within a nucleus

Some enzymes work outside the body cells.

The digestive enzymes are produced by specialised cells in glands and in the lining of the gut. The enzymes then pass out of the cells into the gut where they come into contact with food molecules.

They catalyse the breakdown of large INSOLUBLE molecules into smaller

SOLUBLE molecules.

Page 37: Bacterial cell – genetic information not contained within a nucleus

Name Where it is made

The nutrient it catalyses

What it breaks down into

Where the break down occurs in the body

Amylase Salivary glandsPancreasSmall Intestine

Starch(carbohydrates)

Glucose MouthSmall Intestine

Protease StomachPancreasSmall Intestine

Proteins Amino acids

StomachSmall Intestine

Lipase PancreasSmall Intestine

Lipids (fats

Fatty acids and glycerol

Small Intestine

Page 38: Bacterial cell – genetic information not contained within a nucleus

The stomach produces

hydrochloric acid to create the optimum conditions for the protease

enzymes in the stomach

Page 39: Bacterial cell – genetic information not contained within a nucleus

Bile neutralises the acid that was added to

food in the stomach. This

provides alkaline

conditions in which enzymes

in the small intestine work

most effectively.

Page 40: Bacterial cell – genetic information not contained within a nucleus

QUIZ!1. Name the enzyme that breaks down fats?2. Name the enzyme that breaks down proteins?3. Name the enzyme that breaks down carbohydrates?4. What are fats broken down into?5. What are proteins broken down into?6. What are carbohydrates broken down into?7. Where is amylase made?8. Where is protease made?9. Where is lipase made?10. Where is bile produced?11. Where is it stored?12. What does it do?

Page 41: Bacterial cell – genetic information not contained within a nucleus

ENZYMES IN INDUSTRY

From microorganisms

More effective at low

temperatures than other washing powders

Isomerase – converts glucose

into fructose

Page 42: Bacterial cell – genetic information not contained within a nucleus

• In industry, enzymes are used to bring about reactions at normal

temperatures and pressures that would otherwise require

expensive, energy-demanding equipment.

• However, most enzymes are denatured at high temperatures and many are costly to produce.

Page 43: Bacterial cell – genetic information not contained within a nucleus

QUIZ!1. What type of organisms produce

enzymes that are used in industry?2. What enzymes are found in washing

powders?3. What enzyme converts glucose into

fructose?4. Why is fructose used in slimming

foods rather than glucose?

Page 44: Bacterial cell – genetic information not contained within a nucleus

RESPIRATION

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from the digestive system

from the breathing system

useful!waste product exhaled

waste product exhaled

AEROBIC Respiration is the process that the body uses to release energy from digested food (glucose):

carbondioxideglucose oxygen water energy

Happens in all cells all the time in plants & animals inside mitochondria

Page 46: Bacterial cell – genetic information not contained within a nucleus

Which cells contain more mitochondria? Why?

• Muscles, liver and kidneys

• They require more energy

• They use energy at a higher rate, especially during exercise

The folded layers produce a large surface area for the chemical reactionsThe large surface area means more enzymes can attach to the substrates to catalyse the reactions

Page 47: Bacterial cell – genetic information not contained within a nucleus

REASONS• Respiration releases energy from the food we

eat so body cells can use it• Builds large molecules up from smaller

ones to make new cell material (synthesis reactions) – example – sugars and nitrates are built into amino acids which are then used to make proteins

• Makes your muscles contract – whether aware of or not – e.g. sleeping – heart beats, breathe, gut churns!

• On cold days we use energy to keep warm and on hot days use energy to sweat and keep cool – WARM BLOODED

Page 48: Bacterial cell – genetic information not contained within a nucleus

QUIZ!1. Write the equation for aerobic

respiration2. Where does respiration occur?3. Which cells contain more

mitochondria?4. Give two reasons for respiration

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•What changes happen during

exercise?

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What do these changes mean?

• Increase the blood flow to the muscles and so

increase the supply of glucose and oxygen and

increase the rate of removal of carbon

dioxide.

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If insufficient oxygen is available during exercisewhat type of respiration

happens?

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• Anaerobic respiration is the incomplete

breakdown of glucose and

produces lactic acid

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HIGHER LEVEL!• As the breakdown of glucose is

incomplete, much less energy is released than during aerobic respiration.

• Anaerobic respiration results in an oxygen debt that has to be repaid in order to oxidise lactic acid to carbon dioxide and water.

Page 54: Bacterial cell – genetic information not contained within a nucleus

EXTRA!• If muscles are subjected to long

periods of vigorous activity they become fatigued, i.e. they stop contracting efficiently.

• One cause of muscle fatigue is the build-up of lactic acid in the muscles. Blood flowing through the muscles removes the lactic acid.

Page 55: Bacterial cell – genetic information not contained within a nucleus

QUIZ!1. What does anaerobic mean?2. What is produced in anaerobic

respiration?3. Why is more energy produced with

aerobic than anaerobic respiration?4. What is the ‘oxygen debt’?5. What is one cause of muscle

fatigue?

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GENETICS

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• In body cells the chromosomes are normally found in pairs. Body cells divide by mitosis. The chromosomes contain the genetic information

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MITOSIS MEIOSISOccurs during growth or

to replace body cellsProduces gametes

Occurs in every cell in body

Occurs only in ovaries/testes

Cell divides once Cell divides twiceProduces 2 daughter

cellsProduces 4 daughter

cellsAsexual Sexual

2 sets of chromosomes (46)

One set of chromosomes (23)

Produces genetically identical copies

Produces variation

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• When a cell divides to form gametes:–copies of the genetic

information are made–then the cell divides

twice to form four gametes, each with a single set of chromosomes.

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QUIZ!1. How do body cells divide?2. Where are the chromosomes found?3. How many daughter cells does mitosis

produce?4. How many daughter cells does meiosis

produce?5. Where does meiosis occur?6. What does meiosis produce?

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• Most types of animal cells differentiate at an early stage whereas many plant cells retain the ability to differentiate throughout life.

• In mature animals, cell division is mainly restricted to repair and replacement

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STEM CELLS• Cells from human embryos and

adult bone marrow, called stem cells, can be made to differentiate into many different types of cells, e.g. nerve cells.

• Human stem cells have the ability to develop into any kind of human cell.

• Treatment with stem cells may be able to help conditions such as paralysis.

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• Sexual reproduction gives rise to variation because, when gametes fuse, one of each pair of alleles comes from each parent

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Each gene may have different forms called

allelesDomina

nt Recessi

ve

Page 68: Bacterial cell – genetic information not contained within a nucleus

Gene is a small section of DNA

Chromosomes are made of DNA

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Each gene codes for a particular combination of

amino acids which make a

specific protein

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Each person (apart from identical twins)

has unique DNA. This can be used to

identifyindividuals in a

process known as DNA fingerprinting

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QUIZ!1. What is a stem cell?2. Where are they produced?3. What is an allele?4. What is a gene?5. What are chromosomes made of?6. Why does sexual reproduction give rise to

variation?

Page 72: Bacterial cell – genetic information not contained within a nucleus

Polydactyly

Cystic fibrosis

Embryo screenin

g?