Cells

Cell Theory All living things are made of cells Cells are the basic units of structure, function and physiology in living things Living cells can come only form other pre- existing cells Cells contain and pass on hereditary information during cell division All cells have the same chemical composition and metabolic activity

Robert Hooke – Used simple microscopes to observe objects Was the 1 st to use the term “Cell” Identified plant cells in a cork Father of Biology

Cell Theory Scientists Anton Van Leeuwenhoek – 1 st to describe bacteria and observe prokaryotic cells. Matthias Schleiden – Discovered that all plants are made of cells Theodor Schwann – Observed cells in animal tissue – all animals are made of cells Rudolf Virchow – Determined that every cell comes from another cell

Two Classifications of Cells Prokaryotic Cells –1st form of life –No nucleus –Only form Unicellular organisms (one celled) –Example: Bacteria Eukaryotic Cells –Formed from prokaryotes –Have a nucleus –Form unicellular and multi-cellular organisms. –Example: Plants and animals

Comparing Prokaryotic and Eukaryotic Cells ProkaryotesEukaryotes Have cell wall or membrane Have DNA Have cytoplasm Have Organelles Have a nucleus Have membranes surrounding organelles Are mostly bacteriaInclude all plant and animal cells

Plant and Animal Cells Plant Cells –Eukaryotic cells –Contain a cell wall –Contain chloroplasts –Have large vacuoles –Square or rectangular shaped Animal Cells –Eukaryotic cells –No cell wall –No chloroplasts –Small vacuoles –Found in many shapes –Humans have about 210 different types of animal cells

Animal Cell

Plant Cell

Cell Wall Provides plant cells with structure and support

Cell/Plasma Membrane Outer lining of cells that controls what goes in and out of the cell

Nucleus Control center of eukaryotic cells that contains DNA

Lysosomes Stores enzymes and digests food.

Ribosomes Makes and synthesizes proteins for the cell

Centrioles and Centrosomes Used by the cell in cell division during mitosis and meiosis.

Chloroplasts Produces energy during photosynthesis in plant cells

Vacuoles Stores water and other nutrients for the cell

Golgi Apparatus (Body) Stores, modifies and secretes proteins for the cell.

Endoplasmic Reticulum Rough ER –Contains Ribosomes –Packages and transports proteins throughout the cell Smooth ER –Stores steroids

Nuclear Membrane Outer lining of the nucleus that controls what goes in and out of the nucleus Surrounds and protects the nucleus

Cytoplasm Liquid inside the cell that allows movement and which organelles float in

Mitochondrion Produces energy for the cell

DNA – Deoxyribonucleic Acid Carries the genetic information that make up chromosomes inside the nucleus of cells

Cellular Respiration Process by which chemical energy from food is released to form ATP that the cell uses for energy.

Photosynthesis Process in which producers (plants) convert energy from light, carbon dioxide and water into glucose (sugar) to provide energy for the cell.

Cell Permeability The permitting or activating of the passage of substances into, out of, or through cells. (water, nutrients, oxygen, etc.) Molecular Transport –Active Transport - Materials require energy to move through a cell membrane –Passive Transport - Materials do not requires help (energy) to move through a cell membrane.

Movement of molecules Passive Transport Diffusion - Movement of molecules from an area of great concentration to an area of lesser concentration. Osmosis - Passive transport of water through a cell membrane by diffusion

Mitosis -When cells split Simple duplication of a cell and all it’s parts. Duplication of DNA into two new cells. Phases: –Prophase - cell gets ready –Metaphase - DNA lines up –Anaphase - separation begins –Telophase - division finishes up –Interphase - normal state of cell

Meiosis - Two Divisions For sexual reproduction Reproduces a new organism Second division divides the chromosomes in half Final phase ends with 4 haploid cells called gametes (example - egg and sperm)