19. Animal cells Complex organisms like you are made up of many different kinds of cells. Nucleus controls what the cell does. Contains the DNA (with genes) Cytoplasm is where all the chemical reactions take place. Cell membrane holds the cell together and controls what goes in and out of the cell.
20. Plant cell Plant cells are very special as they can trap sunlight and store the energy as “plant food” Nucleus controls what the cell does. Contains the DNA Cytoplasm is where all the chemical reactions take place. Cell membrane holds the cell together and controls what goes in and out of the cell Chloroplasts containing chlorophyll for photosynthesis Vacuole containing cell sap, a solution of sugar and salts. Ridged cell wall made of cellulose, gives support for the cell
21. The design of a cell is a clue to its function. This group of four cells are very thin. This would allow small molecules to pass through them So what do you think this cell is specialised for. These cells are specialised for lining blood capillaries. If you look carefully you can usually work out what the cell speciality is.
22. Can you work out what this cell’s function is? The obvious feature is the hairs. Hairs on cell usually indicate that its function is for moving something. This cell is specialised for moving egg cells inside the female reproductive systems.
23. Comparing animal cell and plant cells Both cells have:- A nucleus Cytoplasm Cell membrane But only plant cells have:- A cell wall A vacuole Chloroplasts Remember there are lots of different kinds of animal and plant cells but all of them have the above features
24. 6 7 8 9 A white blood cell B gland cell C sperm cell D capillary wall cell The drawings show four kinds of cell that are found in the human body. Match up their names.
25. The drawings show four kinds of cell that are found in the human body. A B C D 10. Which kind of cell is specialised for ingesting microbes? 11 . Which kind of cell is specialised for communicating with many other cells? 12. Which kind of cell is specialised for moving egg cells inside the female reproductive system? 13. Which kind of cell is specialised for moving oxygen around the body?
34. Diffusion through a membrane Cell membrane Inside cell Outside cell diffusion
35. Diffusion through a membrane Cell membrane Inside cell Outside cell EQUILIBRIUM
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38. Osmosis : The net movement of water molecules along a concentration gradient from an area of high water concentration (HWC) to an area of low water concentration (LWC) through a selectively permeable membrane . Osmosis is just a special case of DIFFUSION
76. 21 trisomy – Downs Syndrome Can you see the extra 21 st chromosome? Is this person male or female?
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83. Enzymes Enzymes are biological catalysts. They help the reactions that occur in our bodies by controlling the rate of reaction. Yeast is an example of an enzyme. It is used to help a process called fermentation: The alcohol from this process is used in making drinks and the carbon dioxide can be used to make bread rise. Enzymes work best in certain conditions: Enzymes are denatured beyond 40 O C Sugar Alcohol + carbon dioxide Enzyme activity Temp pH pH 40 0 C Could be protease (found in the stomach) Could be amylase (found in the intestine)
84. Enzymes - Where can we find them? Meat tenderisers Washing powders Err, but you just said that they were In all living cells didn't you ?
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89. Enzymes – How they work! Enzymes Big Molecule of Protein (for example) Lots of Smaller Amino-acids
97. Temperature & Enzyme Activity All enzymes are made of PROTEIN so are DENATURED at high temperatures (above about 50°C) .. think boiled eggs !! The rate of enzyme activity increases with temperature up to a maximum ( OPTIMUM TEMP .) then falls to zero as the enzyme is denatured.
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99. Uses of enzymes 1) Enzymes are used in washing powders to help digest food stains. Biological washing powders will only work on 40 0 C or lower. 2) Enzymes are used in baby foods to “pre-digest” the proteins. 3) Enzymes are used to convert starch into sugar which can then be used in food. 4) Conversion of glucose into fructose – glucose and fructose are “isomers” (they have the same chemical formula), but fructose is sweeter. Daz
103. Aerobic Respiration Aerobic means using oxygen (with air) and it is the most efficient method of energy production Word equation Glucose + Oxygen = Carbon dioxide + Water + Energy Symbol equation C 6 H 12 O 6 + 6O 2 = 6CO 2 + 6H 2 O + Energy
104. O 2 + Glucose ----> CO 2 + H 2 O + ENERGY AEROBIC RESPIRATION Vital chemical reaction going on in all living cells all the time Process converts the CHEMICAL energy in the food we eat into other forms of useful energy - heat, movement, cell reactions Raw Materials for respiration are OXYGEN and GLUCOSE We get these by breathing in O 2 ( LUNGS ) and consuming animals & plants for food. ENZYMES : speed up all cellular reactions. Digest large insoluble molecules of food into small, soluble molecules that can pass through cell membranes Raw materials and end products of respiration get into and out of cells by DIFFUSION & OSMOSIS The CIRCULATORY SYSTEM ( heart, blood vessels ) transports the raw materials & end products around the body to all cells. We need to move and co-ordinate our senses to find food to eat … EYES, EARS, NERVOUS CONTROL & THE BRAIN, REFLEXES
107. Getting energy from food -The Equation + Glucose Oxygen Carbon Dioxide Water Energy + +
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109. Where do we get the raw materials from? - Oxygen Breathing Gaseous exchange in the lungs and
110. How do we remove the waste products? Carbon Dioxide via Breathing Water via urine and breathing and Heat energy may also be released from cells during respiration
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