Unit 3: Biology Date:____________________
2.1 Plant and Animal Cells
Cell Theory
• States that:
– All living things are made up of one or more cells
– The cell is the smallest unit of life
– All cells come from other cells- they do not come from non-living matter
Cells are Alive!
• All cells have to perform the same basic activities to stay alive
• use energy
• store materials
• bring materials inside from environment
• get rid of waste
• move substances to where they are needed
• Reproduce
There are 2 major types of cells:
-Animal - Plant
Organelles:
• Cells have specialized parts (“little organs”) that carry out specific functions
• they all work together
Unit 3: Biology Date:____________________
Organelle Description PictureLysosome • Contain enzymes that can break down
molecules• They are like a garbage dump for the cell
Cytoplasm • Aqueous (water-based) solution inside the cell
• Organelles are suspended in here
Cell Membrane
• A thin, double layered film that separates the interior of the cell from the external environment
• Supports the cell and controls movement in and out of the cell (‘semi permeable’)
Nucleus • “control centre”- directs all cell’s activities• Contains the cell’s DNA (genetic
information) in chromosomes
Mitochondria • Produce energy for the cell via cellular respiration
• Have an inner and outer membrane• Cells that require lots of energy (ex. muscle
cells) will have more mitochondria
Endoplasmic Reticulum (ER)
• System of tubes and canals around the nucleus
Transport materials (ex. proteins and lipids through cell
Ribosomes • tiny, spherical balls that make cell’s proteins• Located in the cytoplasm but also attached
to the rough ER
Unit 3: Biology Date:____________________
Golgi Apparatus
• Several tubes- looks like a stack of flattened balloons
• Packages materials to be removed from cell• Secretes mucus
Vesicle • Membrane-covered sacs that transport/store materials in the cell.
• Also help waste exit the cell
Vacuoles • Membrane bound sacs filled with a watery solution
• Much larger in plant cells• Pressure against cell membrane push it
firmly against the cell wall- turgor pressure
Cell Wall • Plant cells only• Tough, rigid layer that surround cell- made
of cellulose• Provides support and structure
Chloroplasts • Contains all the chemicals (chlorophyll) for photosynthesis
• Have an inner and outer membrane• Looks like a stack of pancakes
Animal vs. Plant
ANIMAL PLANT
Lysosomes No lysosomes
Small vacuoles Large vacuoles
No cell wall Cell wall
No chloroplasts Chloroplasts
Rounded shape Brick shapedCell Diffusion for Growth
• materials must pass through the cell membrane to get in and out of the cell
Unit 3: Biology Date:____________________
• Diffusion: Chemicals move from an area of high concentration to low concentration
Why Diffusion?
• How chemicals move from organelle to organelle
• How oxygen gets delivered to your organs.
• How nerve cells communicate to each other
Osmosis
• Diffusion of water across the semi-permeable membrane dues to concentration differences
• water moves toward the most concentrated, away from the most dilute