(Aligned with 7.1 Intro Sheet and 7.2 Cell Structure Chart)
IMPORTANT: My hope is that you will use this on your computer as a way to ensure that your chart is filled in completely. If you MUST print it out, please make sure you print SIX SLIDES
PER PAGE!! Save a tree!!

 Anton van Leeuwenhoek (1600s) – given credit for developing the 1st mini microscope, looked at pond water and made detailed drawings
 Robert Hooke – coined the term “cell” when he looked at slices of cork and dead plant cells
 Robert Brown (1833) – observed a dark structure near
 the center of the cell (we now know this is the nucleus)
 Matthias Schleiden (1838) – stated all plants are made
 of cells
 Theodore Schwann (1839) – stated all animals are made from cells
 Rudolph Virchow (1855) - stated all cells come from the division of preexisting cells
 Lorenz Oken – stated all new cells are the result of division of preexisting cells…VIRCHOW STOLE HIS
THUNDER

 All living things are composed of cells.
 Cells are the basic units of structure and function in living things.
 All cells come from preexisting cells.

Exploring the Cell : Microscopes
* Lenses used to magnify image by focusing beams of light OR electrons
• Magnification = image size * Resolution = clarity of detail
The light microscope (LM):
• Enables us to shape and structure of a cell
• Magnify cells up to 1,000X
The electron microscope (EM):
• Allows greater magnification and reveals cellular details
• Magnify cells up to 2 mill X
• Limits: no living specimens
Figure 4.1B
Figure 4.1C
Scanning EM:
(SEM) surface structures
Figure 4.1D
Transmission EM:
(TEM) inside details

A small cell allows a sufficient surface area to allow nutrients and wastes to cross per it’s volume.
(in other words: it can’t get too big for it’s own good) volume= 27,000
Ratio: .2 to 1 volume= 27,000
Ratio: .6 to 1 need as high a surface area to volume ratio as possible

ALL cells:
* contain cytoplasm, cell membrane, and DNA
* are either a prokaryotic or a eukaryotic
Prokaryote
• The smallest cells in nature
• DNA not contained in a nucleus, free in the cytoplasm
• Ribosomes are the ONLY cell organelle
• Who are they? Bacteria
Eukaryote
• Much larger and more complex
• DNA is wrapped with a nuclear membrane (nuclear envelope)
• MANY more cell organelles
• Who are they? Protists,
Fungi, Plants, Animals

A. Cellular Control Center
• Nucleus, nucleolus, chromatin/chromosomes, nuclear membrane/pore
B. Organelles that Store, Clean Up and Support
• Vacuoles, vesicles, lysosomes, cytoskeleton (microtubules, microfilaments), centrioles
C. Organelles that Build Proteins
• Ribosomes, endoplasmic reticulum (smooth and rough), golgi apparatus
D. Organelles that Capture and Release Energy
• Chloroplasts, mitochondria
E. Cellular Boundaries
• Cell wall, cell membrane
F. Fluid Portion Outside of Nucleus (Sort of a boundary!)
• cytoplasm

 Function:
 Information center of the cell
 Contains DNA (chromatin vs. chromosomes)
 Directs cell activities
 2 categories of organisms
 Prokaryotes – organisms whose cells lack nuclei (i.e. bacteria)
 Eukaryotes – organism whose cells contain nuclei

Structure:
 NUCLEOLUS – a small, darkened region in the nucleus that is made up of RNA and proteins, this is where ribosomes are made
 CHROMOSOMES – large structures formed from
DNA that contain the genetic info
 CHROMATIN – uncondensed DNA found in non-dividing cells
 NUCLEAR ENVELOPE – double membrane around the nucleus that contains pores, allows molecules to move in and out of the nucleus, and protects the nucleus
 NUCLEAR PORES – allows passage of materials into or out of nucleus (RNA, ribosomes)

 Structure:
 Large, central structure in plants
 Many, small, circular structures in animal cells
 Filled with liquid
 Function:
 Storage of water, salts, proteins, carbohydrates, waste products
 Pressure system for plants, prevents wilting
 Special case: contractile vacuole - prevents excess water intake, leading to cell-bursting

ORGANELLES THAT STORE, CLEAN
UP, SUPPORT:
 Store and move materials between cell organelles and to/from cell surface

ORGANELLES THAT STORE, CLEAN
UP, SUPPORT:
 Structure:
 Small, circular structures
 Found only in animal cells
 Contain digestive enzymes
 Function:
 Digestion of:
 Worn out organelles
 Debris
 Large ingested particles
 Lysosomes are responsible for your hands not being webbed!!

 Structure:
 Hollow tubes of proteins
 Examples: cilia (cells lining tracea), flagella (sperm cells), centrioles
 Function:
 Framework
 Provide cell with support, structure and shape
 Movement (cilia, flagella)
 Microfilaments – made of actin threads,allow movement of cytoplasm within the cell (cytoplasmic streaming)
 Microtubules – hollow structure made of tubulin, maintain cell shape, make up cilia, flagella and centrioles



 Structure:
 Differ based on type of plastid (chloroplast is one example)
 Found only in plants
 Function:
 Store food/starch
 Store pigments (give color to fruits & veggies)

 Structure:
 Small (25 nm) ball-like structures
 Found free-floating in cytoplasm or attached to rough endoplasmic reticulum
 Composed of RNA and protein
 Make peptide bonds between amino acids  protein
 Function:
 Synthesis of proteins (where proteins are made)

 Structure:
 Network of flattened sacs
 Can be rough (w/ ribosomes) or smooth (w/o)
 Function:
 Transport materials within or out of cell
 Synthesis of macromolecules
 Rough - proteins, lipids, carbs
 Smooth - lipids

 Structure:
 Flattened stacks of membranes
 Vesicles attached to top and bottom
 Function:
 Collection, modification, packaging of proteins and other substances
 Vesicles attach, deposit materials
 GA modifies materials based on needs
 Vesicles attach to membrane and distribute modified substances

ORGANELLES THAT CAPTURE/RELEASE ENERGY:
 Structure:
 Double membrane
 Elaborate structure inside
 Function:
 Another power station
 Found in plant cells only
 Conversion of light energy (sun) into chemical energy (glucose)

ORGANELLES THAT CAPTURE/
RELEASE ENERGY:
 Structure:
 Double membrane
 Cristae - inner folds, increase surface area
 Outer membrane for protection of cell
 Function:
 “Powerhouse” of the cell
 Able to self-replicate (  # in cells with high energy need)
 Converts sugars into energy for cells

 Only in plants, algae, and some bacteria
 Lies outside the cell membrane
 Function
 Helps to protect and support the cell
 Very porous (water, oxygen, carbon dioxide, etc. can pass through easily)
 Gives rectangular shape to plant cells
 Layers
 1st layer – contains pectin (gluey substance that helps hold the cells together)
 2nd layer – primary cell wall (made of cellulose )
 3rd layer (in woody stems) – secondary cell wall
(composed of cellulose and lignin to make cellulose more rigid)

outer boundary
 Structure:
 Phospholipid bilayer
• hydrophilic heads, hydrophobic tails
 Contains lipids (bilayer), proteins (channels), and carbohydrate chains (identification cards)
 Function:
 Regulates what enters and leaves the cell
 Semi-permeable membrane
 Protection and support




 Describe the steps involved in the synthesis, packaging, and exporting of a protein from a cell.
 What are the two major parts of the cell?
 How do contractive vacuoles help maintain water balance?
 What is the difference between rough and smooth ER?
 Why is the cell membrane sometimes referred to as a fluid mosaic? What part of the cell membrane acts like a fluid? And what makes it like a mosaic?
 How do the properties of lipids help explain the structure of the cell membrane?
 Why do you think it’s important that cell membranes are selectively permeable?

 Describe the steps involved in the synthesis, packaging, and exporting of a protein from a cell.
 Proteins assembled on ribosomes (if targeted for export to cm or to specialized locations w/in cell, complete their assembly on RER  protein in vesicle  Golgi apparatus (further modifies proteins before sorting and packaging them in membrane bound vesicles)  vesicle  final destination
 What are the two major parts of the cell?
 Cytoplasm with organelles, and nucleus
 How do contractive vacuoles help maintain water balance?
 Pump out excess water
 What is the difference between rough and smooth ER?
 Rough has ribosomes, smooth does not
 Why is the cell membrane sometimes referred to as a fluid mosaic? What part of the cell membrane acts like a fluid? And what makes it like a mosaic?
 It is made of many parts (like a mosaic) that can float around in the fluid phospholipid bilayer
 How do the properties of lipids help explain the structure of the cell membrane?
 Hydrophilic lipid heads are attracted to water, hydrophobic fatty acid tails turn away from water. A bilayer forms when heads turn outward towards water inside and outside a cell
 Why do you think it’s important that cell membranes are selectively permeable?
 Allows needed substances to enter and wastes to leave, while keeping molecules that are not needed out