Cell Structure, Types, Organelles

1665- __________________ used a microscope to examine a thin slice of cork and saw “little boxes” Robert Hooke He called them “CELLS” because they looked like the small rooms that monks lived in called Cells Microscope image: http://www.answers.com/topic/microscope Cork image: http://www.cortex.de/img_kork/cork_cells_big.jpg Hooke image: http://www.metaweb.com/wiki/upload/5/5c/Hookeyoungmtwb.jpg

Anton van Leeuwenhoek 1673- _________________________ a Dutch microscope maker was the first to see LIVING ORGANISMS. Anton van Leeuwenhoek Microscope/Leeuwenhoek image: http://www.answers.com/topic/microscope Animation from: http://web.jjay.cuny.edu/~acarpi/NSC/13-cells.htm

1838- ALL PLANTS are made of cells 1839- ALL ANIMALS are made of cells 1855- Medical doctor saw dividing cells in the microscope and reasoned that cells come from other cells Plant image: http://www.epa.gov/maia/images/classification.gif Schleiden image: http://web.visionlearning.com/events/Schleiden_Apr5_2005.htm

Introduction to Cells Cell Theory All living things are MADE OF CELLS Cells are the basic unit of STRUCTURE & FUNCTION in an organism. (cell = basic unit of LIFE) 3. Cells come from the reproduction of EXISTING cells

Why are cells so small? Make more complex organisms Large Surface area to volume ratio Be more efficient Can transport materials across the cell membrane faster. Can transport water across the cell membrane faster.

CELL SIZE http://facstaff.bloomu.edu/gdavis/links%20100.htm Typical cells range from: 5 – 50 micrometers (microns) in diameter

Number of Cells Organisms may be: Unicellular – composed of one cell Multicellular- composed of many cells that may organize

Introduction to Cells Prokaryotes Eukaryotes Pro – Contains DNA no nucleus No membrane bound organelles Bacteria Eu – Contains DNA IN nucleus Contains membrane bound organelles Plants, fungi & animals

Introduction to Cells Eukaryotes Prokaryotes Animal Cell Plant Cell Bacterial Cell

Prokaryotes Nucleoid region contains the DNA Cell membrane & cell wall Contain ribosomes (no membrane) to make proteins in their cytoplasm

Two Main Types of Eukaryotic Cells Usually square or rectangle Usually round

Similarities between plant cells and animal cells Both have a cell membrane surrounding the cytoplasm Both have a nucleus Both contain mitochondria

Differences between plant cells and animal cells Relatively smaller in size Relatively larger in size Irregular shape Regular shape No cell wall Cell wall present

Differences between Plant Cells and Animal Cells Vacuole small or absent Large central vacuole Glycogen as food storage Starch as food storage Nucleus at the center Nucleus near cell wall

Organelles found in ALL EUKARYOTES Found in cells. Have specific functions for keeping the cell alive & making proteins

Cytoplasm -Jelly like substance within the membrane. -Contains all the organelles.

Nucleus -Controls the normal activities of the cell -Contains the DNA (chromosomes)

Nucleolus -Found inside the nucleus - Makes ribosomes.

Ribosomes -Ribosomes – Make proteins.

Endoplasmic Reticulum Rough ER has ribosomes on its surface & assembles proteins. Smooth ER does not have ribosomes on its surface.

Golgi Apparatus/Bodies Receives modified proteins from ER Packages and ships proteins (ribosomes) Transport vesicle

Animation from: http://www.franklincollege.edu/bioweb/A&Pfiles/week04.html See a Golgi movie

Mitochondria -Site of Cellular respiration -Converts sugars into ATP (energy for the cell)

Lysosome Contains digestive enzymes Breaks down food and worn out cell parts for cells

Cell Membrane Cell membrane -Made of phospholipids, protein, and carbs. -Selectively permeable -Controls the movement of materials into and out of the cell

Different kinds of animal cells

Different kinds of plant cells

Plant Cell Organelles Chloroplast Contain the green pigment chlorophyll Traps sunlight to make to make sugars (food) Process called photosynthesis

Plant Cell Cell wall Dead layer Large empty spaces present between cellulose fibers Strong and rigid Freely permeable