Inside Bacteria Describe how to use a light microscope State the structural features of a bacterial cells and describe their functions Compare and contrast prokaryotic and eukaryotic cells

Bacterial cell structure Draw this diagram and then use it to complete the table.

Bacterial Cell Parts Bacteria are REALLY small! What cell structures do they have? Plant cell Animal Cell Bacteria Cell membrane Cytoplasm Nucleus containing chromosomes Mitochondria Ribosomes Chloroplasts (some cells) Cell Wall Vacuole Cell membrane Cytoplasm No nucleus. Circular loop of DNA No mitochondria (small) ribosomes Plasmids (small loops of DNA) Cell wall May have flagella May have slime coat

Dealing with sizes – standard form Can you remember the names of all the size prefixes we learned in lesson 1 and 2? What are they and what is their relationship to each other?

Standard Form How would you compare the size of a bacterial ribosome (20nm) with a football (0.2m)? If you convert them both to the same unit you get either one very big, or one very small number E.g.: Football = 0.22m, Ribosome = 0.00000002m Or Football = 220000000nm, Ribosome = 20nm Figures with so many zeros are hard to read, use and understand. Standard form can be used instead of having such long numbers

Standard form shows figures in the form of a number between 1 and 10 multiplied by a power of 10. A x 10n Where: A is a number between 1 and 10 and n is the power of ten, also called the index number. The index number (n) tells you how many places to the left or right of the decimal point you need to move your number to get it to where it should be if you were writing it out longhand. If the real number A is bigger than one, count how many times you need to move it to the right towards the decimal point to get a number between 1 and 10. The number of times you move it is the index number (n) and it will be a positive number If the real number A is smaller than one, count how many times you need to move it to the left towards the decimal point to get a number between 1 and 10. This time you the index number (n) will be a negative number

An example: 30000 Our number (A) is 30000 We need to move 30000 to the right four times so that we get a number between 1 and 10 (3). This means that 30000 written in standard form is: 3 x 104

So 30000 is 3 x 104 If our initial number had been 31000, what would it be in standard form? We would still have to move it to the right four times to get a number between 1 and 10, but now we would get a decimal 31000 = 3.1 x 104

Examples How would these standard form numbers be written long hand? How would these numbers be written in standard form? 9000000000 65000 120 750000 3230

Another example 0.000005 Now the index number (n) is the number of times we need to move the number to the left to get a number between 1 and 10. We have to move it 6 times, and because the number is smaller than 1, n is a negative number. So 0.000005 is 5 x10-5 What would 0.0000051 be?

Examples How would these standard form numbers be written long hand? How would these numbers be written in standard form? 0.002 0.027 0.0000035 0.00011 0.000000009

Dealing with sizes – standard form How does standard form relate to the size prefixes?

Inside bacteria Quick Quiz © Pearson Education Ltd 2015. Copying permitted for purchasing institution only.

Quick Quiz A bacterium is 20 µm long. How long is it in metres? A bacterium is 5 µm wide. How wide is it in nanometres? 500 nm What part of an animal cell controls the cell’s activities? nucleus © Pearson Education Ltd 2015. Copying permitted for purchasing institution only.

Quick Quiz What do ribosomes make? proteins Name one part that a plant cell might have but an animal cell would not. chloroplast, permanent large vacuole, cell wall © Pearson Education Ltd 2015. Copying permitted for purchasing institution only.

Quick Quiz What do bacteria use to move themselves? flagella Animal and plant cells are eukaryotic. What word describes bacterial cells? prokaryotic 8 Name one structure that an animal cell would have but a bacterial cell would not. nucleus, mitochondria © Pearson Education Ltd 2015. Copying permitted for purchasing institution only.

Quick Quiz 9 What is this format for numbers called: A × 10n? standard form 10 What is 1 × 106 m written as an ordinary number? 1 000 000 m © Pearson Education Ltd 2015. Copying permitted for purchasing institution only.