Cells

What are you made of? Ancient Greeks thought everything was made of four substances: Earth Air Fire Water

Evolved approx. 3.8 BYA from coacervates Prokaryotes are 1st cells Cell Evolution Evolved approx. 3.8 BYA from coacervates Prokaryotes are 1st cells SIMPLE cells, unicellular bacteria Through endosymbiosis, formed Eukaryotic cells about 2 billion years later (1.5 BYA) COMPLEX, uni & multicellular organisms that are NOT bacteria

Cell Study Cytology – study of cells Microscopes Blenders & centrifuge

Discovery of the Cell Robert Hooke (1665) First to observe cells Looked at cork Named for the “cells” where monks slept

Discovery of the Cell Leeuwenhoek Schleiden Virchow

Cell Theory Accumulation of years of examination and research gave us this theory: All living things are made up of one or more cells Cells are the basic units of structure and function in living things Cells come only from other cells

2 cell types Prokaryote Eukaryote

Cell Structure Cell structure relates to cell function

What parts do ALL cells have in common? Outer covering “Stuff” inside DNA for directions

Cell Membrane Surrounds the cell Made of lipids and proteins Living Jobs Protection Support/shape Controls what enters/exits Homeostasis

Cell Wall Surrounds some cells Plants and bacteria Not living Made of cellulose Jobs Support Allows plants to live without skeleton Protection

Nucleus Holds the DNA on chromosomes Control center of the cell All cell activities Surrounded by the nuclear membrane Contains nucleolus Make ribosomes  make proteins

Nucleus

Cytoplasm Fills space inside the cell Where most life processes take place metabolism

Eukaryotes & organelles Membrane bound “little organs” Organelles “organize” the cell Divide up the duties Allow for specialization More efficient cells

Mitochondria Provide energy for the cell Break down glucose  ATP energy through cellular respiration “Powerhouse” of the cell “Mighty mitochondria”

Plastids Chloroplast Other plastids Filled with chlorophll sun’s energy is converted into glucose during photosynthesis Other plastids Storage of pigments and food chromoplasts store colors of the fall leaves                                                                                                                                                                                                             

Vacuole Liquid filled space Holds wastes and toxins Large in plant cells “Storage Bins”

Lysosome Contains digestive enzymes Breaks down waste into elements for re-use Jobs – “recycling center”

Ribosomes Make proteins Some found on the ER Jobs – “final product” of cell

Endoplasmic reticulum (ER) Tubes and canals that move materials around in the cell Rough or smooth “Cellular Highway” system

Golgi Apparatus (body)                                                                               Final processing and packaging center for proteins made in the cell “UPS or Post Office”

Centrioles & Microtubules Give cell structure “Cytoskeleton” Involved in animal cell reproduction

Compare Animal & Plant cell Animal cells No cell wall Few, small vacuoles Nucleus centered centrioles No plastids Plant cells Cell wall Large central vacuole Nucleus pushed to side No centrioles Plastids Chlorophyll, other pigments

Differentiation Stem cells are “blank cells” – templates for all other cells Differentiation How cells use DNA directions to become different Nerve cell, eye cell, skin cell, etc.

Organization in Living Things Multicellular organisms have billions of cells Tissues Organs Organ system Organism