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Unit One: Cell Biology.

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1 Unit One: Cell Biology

2 S3 CFE Biology Units: Cell Biology – now till October
Multicellular Organisms – October – Feb Life on Earth – February onwards S3 Biology Course Unit 1

3 How is the course assessed?
There will be an end of topic test at the end of Unit 1 and Unit 2. This will test your knowledge of the unit and your problem solving (calculations, %, line/bar graphs). S3 Biology Course Unit 1

4 Course Work As well as the tests, there are three pieces of course work to do: Unit 1: Practical investigation Unit 2: Short Scientific Report Unit 3: Research Assignment S3 Biology Course Unit 1

5 Key area 1: Cell structure
Learning objectives: Identify and name the structures in a plant cell Identify and name the structures in an animal cell State the functions of the structures found in plant and animal cells Be able to work out the size of a cell S3 Biology Course Unit 1

6 Prior Knowledge From CSI Speyside you should know:
That cells are the basic unit of all living things How to use the microscope Some parts of animal and plant cells and what their role in the cell is. S3 Biology Course Unit 1

7 Examining plant cells Your teacher will remind you how to make a microscope slide. Look at the onion cells under the x10 lens and draw what you can see in your jotter. S3 Biology Course Unit 1

8 X 40 S3 Biology Course Unit 1

9 Collect and label this diagram of a plant cell
Typical plant cell S3 Biology Course Unit 1

10 Functions Use page 19 of the N5 textbook to find out what the following parts of the cell do: Nucleus Cell membrane Cytoplasm Cell wall (Sap) Vacuole Chloroplast Ribosome Mitochondria Display this in your jotter as a table or list. S3 Biology Course Unit 1

11 Examining animal cells
Your teacher will show you how to make a slide of your cheek cells. Using x 10 magnification draw what you can see. S3 Biology Course Unit 1

12 X 100 S3 Biology Course Unit 1

13 Collect and label this diagram of an animal cell
Typical animal cell Collect and label this diagram of an animal cell S3 Biology Course Unit 1

14 Common structures Make two columns in your jotter:
Plant and Animal Plant cells Cells Only Fill in which cell parts should go in each column. S3 Biology Course Unit 1

15 This link will show you how tiny cells are.
Just how tiny are cells? “How big?” This link will show you how tiny cells are. Cells can be seen more clearly using a microscope. S3 Biology Course Unit 1

16 Magnification Total magnification is worked out by multiplying the eyepiece lens magnification by the objective lens magnification. Eyepiece Lens Objective Lens S3 Biology Course Unit 1

17 Copy and complete this table
Eyepiece lens magnification Objective lens magnification Total magnification X 10 X 4 X 100 S3 Biology Course Unit 1

18 Working out the size of a cell
The field of view is the area you can see down the microscope. Field of view = 2 mm Field of view Length = of each cell (mm) Number of cells e.g. 2 ÷ 5 = 0.4 mm So each cell measures 0.4 mm. S3 Biology Course Unit 1

19 Collect a version of this diagram.
Field of view = 2 mm Collect a version of this diagram. Your teacher will tell you how many cells to draw in the circle. Calculate the length of your cell in millimetres (mm). Swap with other and calculate the length of their cells. S3 Biology Course Unit 1

20 Key area 2: Cell membrane and Transport
Learning objectives: Describe what the cell membrane is made of Describe what is meant by “diffusion” Explain how the process of diffusion occurs across the cell membrane S3 Biology Course Unit 1

21 Prior Knowledge From Science in everyday life you should know:
The three states of matter are – solid, liquid and gas. The particles behave in different ways depending on if they are in a solid, liquid or gas. S3 Biology Course Unit 1

22 How are particles arranged?
Solid Liquid Gas Copy this table. Using a circle to show the particles – fill in the space to show how the particles are arranged. S3 Biology Course Unit 1

23 How are particles arranged?
Solid Liquid Gas S3 Biology Course Unit 1

24 How to liquids and gases move?
Your teacher will take you outside (or to the auditorium) to pretend to be particles. Based on what you did, write a couple of sentences describing how particles of liquid or gas move. S3 Biology Course Unit 1

25 The cell membrane in close up
Copy this diagram S3 Biology Course Unit 1

26 The cell membrane is made of lipids and proteins.
The lipids are arranged in a double layer. The proteins are in a patchy arrangement. Some stick all the way through making channels called “pores”. S3 Biology Course Unit 1

27 Diffusion What happens to the smell when you spray perfume in one corner of the room? S3 Biology Course Unit 1

28 Gas or liquid particles are constantly moving and bumping into each other. This means that they spread out from an area where there are lots of particles to an area where were are no particles. S3 Biology Course Unit 1

29 This process is called diffusion.
Diffusion is the movement of molecules of a substance from an area of high concentration to an area of low concentration until they are evenly spread. S3 Biology Course Unit 1

30 Diffusion through a membrane
Starch Glucose In bag In water at the start In water after 20 mins Water Visking tubing Starch + Glucose solution S3 Biology Course Unit 1

31 Take a small sample of the water from around the test tube
Take a small sample of the water from around the test tube. Test for starch and sugar 2. Add 4 drops of IODINE Test for starch 1. Put sample on tray 3. If starch is present it goes from brown to black 2. Add 4 drops of BENEDICTSSOLUTION Test for sugar BOILING WATER 1. Put sample in test tube – IN a beaker of BOILING WATER 3. If sugar is present it goes from blue to orange S3 Biology Course Unit 1

32 S3 Biology Course Unit 1

33 Conclusion: Glucose molecules can diffuse through Visking tubing but starch molecules cannot. Explanation: Visking tubing is a selectively permeable membrane. S3 Biology Course Unit 1

34 A Selectively Permeable Membrane
A selectively permeable membrane contains tiny holes through which only tiny molecules can diffuse. Cell membranes are also selectively permeable. S3 Biology Course Unit 1

35 They control the movement of substances in and out of cells
They control the movement of substances in and out of cells. Small molecules which can diffuse through a selectively permeable membrane are: oxygen glucose water carbon dioxide S3 Biology Course Unit 1

36 Large molecules which cannot diffuse through are: Starch Protein
S3 Biology Course Unit 1

37 Substances which can and cannot diffuse into or out of cells
Carbon dioxide Starch Protein Glucose Oxygen S3 Biology Course Unit 1

38 Why is diffusion important?
Diffusion is essential to living things. All cells need to take in food (e.g. glucose and amino acids) and oxygen. These are used for respiration (see later in this unit) to produce energy. S3 Biology Course Unit 1

39 Key area 3: Making new cells
Learning objectives: Explain that cells must divide to increase the number of cells in an organism. State the cell division is controlled by the nucleus. Explain why the original cells must divide to produce two identical daughter cells. Describe the main stages of mitosis. S3 Biology Course Unit 1

40 Prior knowledge From CSI Speyside you should know:
The nucleus of the cell contains chromosomes. Chromosomes are a set of instructions which tell the cell how to work. S3 Biology Course Unit 1

41 What is cell division? Cell division is how an organism makes new cells for growth, development and repair. In cell division one cell divides to make two new cells. The two new cells are called daughter cells and they are identical to the original cell. In unicellular organisms cell division is a way of reproducing. S3 Biology Course Unit 1

42 Inside the nucleus Nucleus contains 46 chromosomes.
These carry information. Each piece of information is packaged on a gene. e.g. gene with information for eye colour S3 Biology Course Unit 1

43 Chromosome complement
Humans have 46 chromosomes in every nucleus inside every body cell. This is called our chromosome complement S3 Biology Course Unit 1

44 The importance of the chromosome complement
The chromosome complement contains all of the codes needed by each cell. It must be copied exactly for each new cell in cell division so that none of the codes (which are the cell’s instructions) are left out. S3 Biology Course Unit 1

45 Stage 1 nucleus containing long uncoiled chromosomes.
each chromosome doubles to form to identical chromatids. S3 Biology Course Unit 1

46 1 chromosome made of two chromatids
doubles 1 chromosome 1 chromosome made of two chromatids S3 Biology Course Unit 1

47 Stage 2 each chromosome becomes thicker – forming a short coiled chromosome (made of two chromatids). S3 Biology Course Unit 1

48 centromere – holds 2 chromatids together.
shortens and coils 1 long uncoiled chromosome made of two chromatids 1 short coiled chromosome made of two chromatids S3 Biology Course Unit 1

49 Stage 3 the chromosomes line up at the equator of the cell.
a spindle forms and attaches at the centromeres. S3 Biology Course Unit 1

50 Stage 4 N pole the chromatids are pulled apart and move to different poles. S pole S3 Biology Course Unit 1

51 Stage 5 a nuclear membrane forms around each group of chromatids – now called chromosomes. the cytoplasm begins to divide. S3 Biology Course Unit 1

52 Stage 6 two daughter cells each containing the same numbers of chromosomes as the original cell. S3 Biology Course Unit 1

53 1 6 2 3 5 S3 Biology Course Unit 1 4

54 2 1 3 6 4 5 Collect this diagram of cell division.
Write a sentence describing what is happening at each stage of the process. Use page to help. 3 6 4 S3 Biology Course Unit 1 5

55 Key area 4: Producing proteins
Learning objectives: State that proteins are made of different sequences of amino acids. Describe some of the main functions of proteins. Describe the structure of DNA. Explain how the DNA helps the cell to make different proteins. S3 Biology Course Unit 1

56 Prior knowledge From Science in Medicine you should know:
Proteins are large molecules made up from 21 different amino acids. From CSI Speyside you should know: Chromosomes are made of a molecule called Deoxyribonucleic acid (DNA). S3 Biology Course Unit 1

57 Proteins Proteins are large molecules made by joining small subunits called amino acids together. There are 21 different amino acids. Different proteins have different combinations of the amino acids. S3 Biology Course Unit 1

58 The amino acid chains can then fold into different shapes which allow the proteins to do different jobs in the cell. Antibody S3 Biology Course Unit 1 Cell membrane pore Keratin (hair)

59 What makes organisms different?
Boardworks GCSE Science: Biology Genes and Genetic Engineering Organisms differ because they have different genes. Humans have human genes Gerbils have gerbil genes Bananas have (yes, you’ve guessed it) banana genes! Nobody else in the whole world has the same DNA as you! S3 Biology Course Unit 1 59

60 Genetic information The nucleus of living cells contain chromosomes which are made up of a string of genes. S3 Biology Course Unit 1

61 Chromosomes and their genes are made of a molecule called DNA
Boardworks GCSE Science: Biology Genes and Genetic Engineering Chromosomes and their genes are made of a molecule called DNA DNA stands for deoxyribonucleic acid. The DNA molecule looks like a twisted ladder this spiral shape is called a DOUBLE HELIX Each chromosome is a very long molecule of tightly coiled DNA. S3 Biology Course Unit 1 61

62 DNA bases Boardworks GCSE Science: Biology Genes and Genetic Engineering The double helix ‘ladder’ of a DNA molecule is held together by ‘rungs’ made from pairs of chemicals called bases. A There are four types of bases, and they are usually identified by their initials. C G T S3 Biology Course Unit 1 62

63 A T C G Base pairs hold the two strands of the DNA helix together.
Boardworks GCSE Science: Biology Genes and Genetic Engineering Base pairs hold the two strands of the DNA helix together. A T C G It is the sequence of these bases along a DNA molecule that forms the genetic code. S3 Biology Course Unit 1 63

64 The genetic code Every three bases in the DNA (codon) tells the cell which amino acid to use to help build proteins. T A T C G G T A C G T A DNA sequence Amino acids joined together in protein Alanine Glycine Proline Cysteine S3 Biology Course Unit 1

65 Translating the DNA code
Your teacher will give each group a DNA sequence. Divide the sequence into groups of three (codons) then use the chart to work out which coloured bead you will need. Put the beads in order based on your sequence. S3 Biology Course Unit 1

66 Use this chart to help you to build your final protein
1st position 3rd position T C A G Yellow Green Red Blue Light Blue White Pink STOP 2nd position T Use this chart to help you to build your final protein C A G S3 Biology Course Unit 1

67 Key area 5: Enzymes Learning objectives:
State that enzymes are found in all cells and speed up chemical reactions. Explain why enzymes are described as “specific” Give examples of “building up” and “breakdown” enzymes and explain what they do. S3 Biology Course Unit 1

68 Prior knowledge From Science In Medicine you should know:
The digestion of starch in your mouth was carried out by a substance in your saliva called an enzyme. S3 Biology Course Unit 1

69 Catalysts A catalyst speeds up a chemical reaction, but is unchanged in the process and can be used over and over again. In living things, catalysts are known as enzymes. S3 Biology Course Unit 1

70 If cells did not have enzymes in their cytoplasm, then the chemical reactions which happen in our cells would happen so slowly that life would be impossible! S3 Biology Course Unit 1

71 An example of an enzyme: CATALASE
Hydrogen peroxide (H2O2) is a liquid similar to water (H2O), but with one extra oxygen. Over a long period of time hydrogen peroxide naturally breaks down into water and oxygen. S3 Biology Course Unit 1

72 The word equation for this reaction is:
Hydrogen peroxide water + oxygen This process can be sped up using an enzyme. S3 Biology Course Unit 1

73 Into each test tube – measure out 5 ml of Hydrogen peroxide AND 5 drops of detergent.
CAUTION!! Hydrogen peroxide is a dangerous chemical. Safety goggles must be worn!! Add nothing Potato Carrot Liver Leave for 10 minutes. Measure the height of the foam bubbles. S3 Biology Course Unit 1

74 Estimating the catalase activity of different food groups
Aim: Dependent variable: Independent variable: S3 Biology Course Unit 1

75 Test tube contents Height of foam (mm) Nothing – “CONTROL” Potato
Carrot Liver S3 Biology Course Unit 1

76 Conclusion Only the plant and animal tissues speed up the breakdown of hydrogen peroxide. This is because the cells contain catalase. Catalase is an enzyme found in living cells. S3 Biology Course Unit 1

77 Hydrogen peroxide water + oxygen
Catalase Hydrogen peroxide water + oxygen The tissue which contained the most catalase was ______________. S3 Biology Course Unit 1

78 Breakdown and Building Up
Catalase is an enzyme involved in chemical breakdown. “Breakdown” means chopping up larger molecules into smaller molecules. S3 Biology Course Unit 1

79 Other enzymes do the opposite – the build large molecules from smaller molecules.
S3 Biology Course Unit 1

80 An example of a “Build up” enzyme: Phosphorylase
Glucose-1-phosphate is a chemical made by plants during photosynthesis. It is stored in plant cells be converting it into a large molecule called starch. S3 Biology Course Unit 1

81 Phosphorylase Phosphorylase Glucose-1-phosphate Starch
S3 Biology Course Unit 1

82 Substrates and products
The substrate is the substance the enzyme works on. The product is the substance the enzyme makes. Enzyme Substrate Product S3 Biology Course Unit 1

83 Enzyme Substrate Product Catalase Phosphorylase Amylase Pepsin Lipase
S3 Biology Course Unit 1

84 How enzymes work Enzymes are made of protein. This protein has a special shape which is unique to each enzyme. Enzyme Active site S3 Biology Course Unit 1

85 The active site is the correct shape to fit the substrate.
Enzyme The active site is the correct shape to fit the substrate. Substrate Turned into the products Enzyme S3 Biology Course Unit 1

86 Substrate Enzyme Other substrates are the wrong shape to fit in the active site of the enzyme. Therefore the enzyme will only work with one substrate. This is described as being SPECIFIC. S3 Biology Course Unit 1

87 “Specific” When talking about enzymes, SPECIFIC means that the ENZYME WILL ONLY WORK WITH ONE SUBSTRATE. S3 Biology Course Unit 1

88 One enzyme = one substrate
5 ml Starch 5 ml Starch 5 ml Starch 5 ml Starch 3 ml Water 3 ml Amylase 3 ml Pepsin 3 ml Lipase Put in waterbath for 10 minutes. Test all 4 test-tubes with Benedict’s Solution S3 Biology Course Unit 1

89 Investigating the specificity of enzymes
Aim: Dependent variable: Independent variable: S3 Biology Course Unit 1

90 Results Sugar present? Starch + water Starch + amylase Starch + Pepsin
Starch + Lipase S3 Biology Course Unit 1

91 Conclusion The test-tube containing Starch and Amylase had the most sugar. This shows that only Amylase can convert starch to sugar. Amylase is said to be SPECIFIC to starch. S3 Biology Course Unit 1

92 “Factors affecting the enzyme activity using the catalase enzyme”
Investigation Design an experiment to investigate: “Factors affecting the enzyme activity using the catalase enzyme” Carry out and write up this experiment – your teacher will give you advice. S3 Biology Course Unit 1

93 Factors affecting the enzyme activity using the catalase enzyme
Aim: Dependent variable: Independent variable: S3 Biology Course Unit 1

94 Key area 6: Respiration Learning objectives:
State what cells use energy for. State the summary word equation for aerobic respiration. Explain when animal cells might use anaerobic respiration. State the summary word equation for anaerobic respiration S3 Biology Course Unit 1

95 Prior knowledge In Science in Medicine you learned that:
Cells get energy from this chemical reaction: sugar + oxygen energy + carbon + water dioxide S3 Biology Course Unit 1

96 Why do cells need energy?
Maintain body temperature Make your muscles work Making larger molecules Cells use energy from respiration to… Carry out chemical reactions Growth and repair of cells S3 Biology Course Unit 1

97 Which foods have the most energy?
Different types of food contain different amounts of energy. The three main food groups are: Carbohydrates Proteins Fats S3 Biology Course Unit 1

98 Estimating the energy content of foods
Aim: Dependent variable: Independent variable: S3 Biology Course Unit 1

99 WATER TEMPERATURE (ºC)
Your teacher will demonstrate how to set up and carry out this experiment safely. NUTRIENT EXAMPLE WATER TEMPERATURE (ºC) At start After burning food % Increase Carbohy-drate Sucrose Protein Gelatine Fat or oil Sunflower Oil S3 Biology Course Unit 1

100 Conclusion: Most energy in the body comes from breakdown of carbohydrates. Carbohydrates are made of the sugar glucose. S3 Biology Course Unit 1

101 Aerobic respiration Aerobic respiration means “with air” and is happening in you body now. 38 energy molecules Carbon dioxide Glucose Oxygen Water Comes from breakdown of your food Breathed in by your lungs Breathed out by your lungs S3 Biology Course Unit 1

102 What happens if you do heavy exercise?
During sports your muscles run out of oxygen because they are working so hard the heart and lungs cannot keep up sufficient supply. When this happens anaerobic respiration occurs. S3 Biology Course Unit 1

103 Anaerobic respiration
2 energy molecules Lactic Acid Glucose Comes from breakdown of your food Builds up in your muscles making them painful Anaerobic respiration only produces 2 energy molecules compared with the 38 produced by normal aerobic respiration. S3 Biology Course Unit 1

104 Key area 7: Photosynthesis
Learning objectives: State that photosynthesis is the process used by plants – where carbon dioxide and water is used to produce sugar and oxygen. Identify and describe the role of the cells in a leaf. State the summary word equation for photosynthesis. Describe how you can measure the rate of photosynthesis and name one factor which affects the rate of photosynthesis. S3 Biology Course Unit 1

105 Prior knowledge You should know from the Planet Earth unit:
Plants produce their own food from sunlight. This process happens in the leaves. This process requires a chemical called chlorophyll. S3 Biology Course Unit 1

106 Collect and label this diagram of a leaf
Leaf Structure Collect and label this diagram of a leaf S3 Biology Course Unit 1

107 Upper and lower Epidermis
Part Function Upper and lower Epidermis Layer of cells on top and bottom of leaf which protect the leaf. Palisade Mesophyll These cells contain loads of chloroplasts. Site of photosynthesis Spongy Mesophyll This layer has air spaces to allow diffusion of gases in the leaf Stomata Pores on underside of leaf to allow gases to enter or leave. Made of two guard cells. S3 Biology Course Unit 1

108 Photosynthesis Photosynthesis occurs in the palisade mesophyll cells.
These cells contain chloroplasts. Chloroplasts contain a green pigment called chlorophyll which traps light energy from the sun. S3 Biology Course Unit 1

109 Light energy Carbon dioxide water Glucose Oxygen Chlorophyll
Is a waste product which exits the leaf through the stomata Enters leaf through the stomata Enters plant through the root S3 Biology Course Unit 1

110 What happens to the glucose?
Use page 84 of the text book to complete this diagram: Glucose S3 Biology Course Unit 1

111 Measuring the rate of photosynthesis
How fast photosynthesis occurs can be estimated by counting the number of bubbles of oxygen produced each minute. Your teacher will show you how to set up this experiment. S3 Biology Course Unit 1

112 Measuring the effect of light intensity on the rate of photosynthesis
Aim: Dependent variable: Independent variable: S3 Biology Course Unit 1

113 Distance from the light (cm)
Number of oxygen bubbles produced in ______ minutes 10 20 30 40 S3 Biology Course Unit 1

114 Conclusion: S3 Biology Course Unit 1

115 S3 Biology Course Unit 1

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117 2 1 3 6 4 S3 Biology Course Unit 1 5

118 S3 Biology Course Unit 1


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