The Plant Cell

R. Gallagher www.theconicalflask.ie Living things and Cells Living things: • All living things must contain some of the following characteristics: 1. Nutrition 2. Movement 3. Response 4. Excretion 5. Growth 6. Reproduction 7. Respiration All of the above must be present in a living thing. However sometimes a characteristic may not be obvious, e.g. movement in plants. Different types of living things • Some of the main groups of living things: 1. Plants 2. Animals 3. Bacteria 4. Fungi 9 R. Gallagher www.theconicalflask.ie The cell A cell is the smallest working unit of a living organism. • All living things are made up of cells - they are essentially the building blocks of life. Robert Hooke • In 1665, Hooke observed cells of cork wood using a microscope. • Cells must be described as tiny and can only be seen by using a microscope. Cells • When we draw cells they are 2d but in reality they are 3d. • There are many types of cell: • Red blood cell • Sperm cell • Body cell • There are only two cell types that you need to know in detail: 1. Plant cells 2. Animal cells 10 R. Gallagher www.theconicalflask.ie The animal cell Cell organelles: Function: Cell membrane • Controls what enters and leaves the cell. • Oxygen and nutrients enter the cell. • Carbon dioxide and waste leave the cell. Nucleus:• Control centre of the cell. • Contains chromosomes which contain genes (DNA). Cytoplasm:• Suspends the cell organelles. Vacuole:• Stores food and water. • Note: The vacuole is found in plant and animal cells. However the plant cell vacuole is much bigger than the animal vacuole. Mitochondria:• Power house of the cell. • Respiration occurs here (release of enemy from food) Ribosome• Produces proteins 11 R. Gallagher www.theconicalflask.ie The plant cell Organelle: Function: Cell membrane• Controls what enters and leaves the cell. • Oxygen and nutrients enter the cell. • Carbon dioxide and waste leave the cell. Nucleus:• Control centre of the cell. • Contains chromosomes which contain genes (DNA). Cytoplasm:• Suspends the cell contents. Vacuole:• Stores food and water. Mitochondria:• Power house of the cell. • Respiration occurs here (release of enemy from food) Ribosome• Produces proteins Cell wall• Provides shape and support only. Chloroplasts• Photosynthesis. • Contains green pigment chlorophyll. • Chlorophyll traps the sunlight & makes glucose. 12 R. Gallagher www.theconicalflask.ie Plant and animal cell comparison Plant cells Animal cells Cell wall present No cell wall Chloroplast present No chloroplast Large vacuole Small vacuole The Microscope Part: Function: Eye piece• Allows you to see the specimen. Stage• Holds the glass slide. Course focus wheel• Brings object roughly into focus. Fine focus wheel• Brings object into sharp focus. Nosepiece• Allows use of different lenses. Objective lens• Magnifies an image. Mirror/light• Provides light to see the object on the stage. 13 R. Gallagher www.theconicalflask.ie Chemicals to highlight the cells: • Iodine is a chemical used to make plant cells clearer. • Methylene blue is a chemical used to make animal cells clearer. Cell organisation • Cells do not work alone and when cells work with similar cells they begin to show how an organism is formed. Tissues: • A group of similar cells to carry out the same function. • e.g. muscle tissue Organs: • A group of tissues working together to carry out the same function • e.g. Lungs, brain, kidneys. System: • A group of organs working together to carry out the same function • e.g. Sensory system and circulatory system. Organism: • Composed of a number of different systems. • e.g. Humans, dogs and daffodils. Cells - Tissues - Organs - Systems - Organism 14

Control centre of the cell. • Contains chromosomes which contain genes (DNA).

Suspends the cell contents.

Stores food and water

Power house of the cell. • Respiration occurs here (release of enemy from food)

Produces proteins

Provides shape and support only.

Photosynthesis. • Contains green pigment chlorophyll. • Chlorophyll traps the sunlight & makes glucose.