cells biology. discovery of cells robert hooke-1665 ▫biologist, inventor, architect physicist,...
TRANSCRIPT
CellsBiology
Discovery of Cells
•Robert Hooke-1665▫Biologist, inventor, architect
physicist, astronomer▫30x, cork…cells
•Anton van Leeuwenhoek▫300x, single-celled organisms
• Introduction - http://www.youtube.com/watch?v=zufaN_aetZI
Cell Theory
•Developed around 1800▫All living things are made up of one or
more cells▫The cell is the smallest unit that still
retains the characteristics of life▫All cells arise from existing cells
Cell Size & Shape
•A larger cell would:▫Take up more nutrients▫Excrete more waste▫Have difficulty transporting nutrients &
waste•Potato Demo
•Shape determines function▫Larger cells = more surface area
Features of All Cells…
•Cell membrane▫Transport (barrier), communicate, identify,
etc. •Cytoplasm
▫Inner fluid & suspended organelles•Ribosome
▫Makes protein•DNA
▫Instruct making of protein, regulates cell activities, & allows cells to reproduce
Prokaryotic Cells
•Single cell, ~ 3.5 bya•Lacks
▫Nucleus ▫Membrane bound
organelles•Has
▫DNA in a single loop…nucleoid
▫Cytoplasm, enzymes▫Ribosomes▫Cell wall, some have
capsule
Bacteria Growth: http://www.youtube.com/watch?v=gEwzDydciWc&NR=1
Eukaryotic Cells• Some single-celled • All multi-celled• ~1.5 bya• More complex
▫Specialized functions• Lacks:
▫Capsule• Has:
▫Nucleus=a membrane bound organelle that contains DNA, directs cell functions
▫Membrane bound organelles=one of the small bodies that are found in the cytoplasm of a cell and that are specialized to perform a specific function
▫Among others
The Cytoskeleton
•Eukaryotes▫Protein fibers▫Move cells▫Provides structure
Shape
Amoeba Moving: http://www.youtube.com/watch?v=7pR7TNzJ_pA
Making Proteins…
•Extremely important!•DNA=Permanent instructions, nucleus•RNA=Copied instructions, goes to
cytoplasm•Ribosomes=Use RNA to make protein•Endoplasmic reticulum=packages
protein•Golgi apparatus=proteins (and other
cell products) are modified, sorted, & shipped▫To cell membrane, using vesicles
Storage & Maintenance
•Maintain homeostasis•Lysosome=use enzymes to break down
waste▫What are enzymes?
•Vacuole=storage of water, nutrients, waste, etc.
•Central vacuole=plantsTurgor Pressure: http://www.youtube.com/watch?v=V56Zy7uLFEAhttp://www.youtube.com/watch?v=lz
DlGl3b4is&feature=related
Energy Production
•Chloroplasts (plant cells)▫Sugar production, stores energy in
chemical bonds From light energy, water, & CO2 Process called?
•Mitochondria (plant & animal cells)▫Converts stored energy to ATP
From sugar Process called?
Cell Membrane• Homeostasis
▫Stable internal conditions in a changing environment• Break down the words…• Phospholipid bilayer
▫Hydrophobic tails (polar or nonpolar?)▫Hydrophilic heads (polar or nonpolar?)
• 4 types of proteins: 1 Cell Surface Markers 2 Receptor Proteins 3 Enzymes 4 Transport Proteins
• Osmosis vs. Diffusion
Osmosis•Transport of water•Solutions: Hyper-(more), Iso-, & Hypo-
(less)
Diffusion
•Transport of molecules/particles▫Passive transport (no energy)
Osmosis Simple diffusion Facilitated diffusion (channel/carrier proteins)
▫Active transport (needs energy) Pumps (e.g. sodium potassium pump) Vesicles (endocytosis & exocytosis)
Microscopes & How They Work
•Necessary to study cells•2 major categories
▫Light microscopes Convex glass
▫Electron microscopes
Using Light Microscopes…
•Set up:▫Carry with one hand on base and one
around arm▫Put coverslip on slide, if needed▫Observe specimen on lowest power first▫Magnify to higher power as needed
Note: as you magnify image, you see less area on slide
▫Clean lenses & slides with chemwipes▫Put away