1. Chapter 3
Nature Of Cells
Chapter 4???
Background same as microscope.

2. Cell Diversity
Cells come in a variety of sizes and shapes. Form follows function.
Size variety
Longest (giraffe) – up to 2m
Largest (birds) – eggs
Most - .2 – 50micrometers (microscope needed)
Shape variety
Examples are:
Nerve cells – long web-like projections for communication
Skin cells – flat for covering
Shape variety – add “examples are”
“Form follows function” – is that enough for students???

3. Common Characteristics of Cells
All cells share certain structural characteristics :
cell (plasma) membrane- membrane surrounding cell
cytoplasm- material inside cell (contains organelles in some cells)
ribosomes-structures where protein is made
DNA- genetic code, codes for protein
All cells are either prokaryotic or eukaryotic.
Cell membrane = plasma membrane??

4. Types of Cells
Cells and organisms are divided into two groups based upon the presence or absence of a membrane-bound nucleus and other organelles
Prokaryotes
Single celled organisms; ex. bacteria
Lack true nucleus; circular DNA
Reproduce asexually (binary fission)
Lack internal organization
Bacteria = “example”
DNA in ring = circular DNA

5. Types of Cells Eukaryotes “true nucleus” membrane-bound organelles
paired chromosomes

6. Parts of the Cell Cell Membrane
The envelope that makes up the outer surface of a cell is called the plasma membrane.
The cell membrane is selectively permeable which means that the membrane keeps out some molecules, but allows others to pass.
Plasma membrane –bold
Highlighted words not consistent in color
Rephrase “controls the sub……” to reflect a more passive operation

7. Cell membranes are composed of two phospholipid layers.
The cell membrane has two major functions.
forms a boundary between inside and outside of the cell
controls passage of materials
cell membrane
outside cell
inside cell

8. Structure of the Cell Membrane
The membrane is made up of two main groups of organic molecules: phospholipids and proteins.
This model of the cell membrane = “fluid mosaic model”.
Highlight color – too dark

9. Phospholipids: Review
Phospholipids form a lipid bilayer in which there are polar (hydrophilic) and nonpolar (hydrophobic) regions.

10. Membrane Proteins Peripheral (extrinsic) Proteins
Located inside membrane and outside cell
Integral (intrinsic) Proteins
Are embedded in membrane and are exposed on both sides of membrane
proteins function as channels, receptors and markers.
Is this detail necessary?

11. Fluid Mosaic Model

12. Cell Rap/Cell Poem Group 1 – Ribosome, Rough ER, Smooth ER, Golgi Body
Group 2 – Mitochondria, Flagella, Cilia
Group 3 – Nucleus, Nucleolus, DNA
Group 4 – DNA, Chromatin, Chromosomes
Group 5 – Peroxisomes, Lysosomes, Cytosol
Group 6 – Cytoskeleton, Microfilaments, Microtubules
Group 7 – Cell Wall, Vacuole, Chloroplast
Page 52-60
Cell Rap

13. Organelles
Organelles: internal membrane-bound structures with various functions necessary for the operation of the cell. Organelles are located in the cytoplasm
Cytosol –
fluid portion of the cytoplasm; contains dissolved materials and organelles
Mitochondria –
Mitochondria are the energy-releasing organelles.
Two membranes
Own set of DNA
Cellular respiration
Is “organelle” defined anywhere?
Move cell resp to list bottom

14. Organelles Ribosomes Made of RNA and protein
Found free-floating in cytoplasm or attached to endoplasmic reticulum.
Not membrane - bound
Site of protein synthesis
Add “No membrane”

15. Organelles Endoplasmic Reticulum (ER) system of membranes
transports materials within the cell
there are two types:
rough - contain ribosomes
- make proteins
smooth - little or no ribosomes
- make lipids

16. Organelles Golgi apparatus
The packaging and distribution center of the cell.
Works with ER to prepare materials for export out of the cell

17. Golgi and ER
The ER transfers material to the Golgi apparatus for final processing
Maybe some info about the flow of these organelles into others WHAT?

18. Organelles
Nucleus
directs all cell activities and stores the cell’s DNA.
The nucleus is surrounded by a nuclear envelope
DNA and protein organized into chromatin (during normal periods) and into chromosomes (before cell division)
DNA is rewritten as RNA which leaves through nuclear pores
Ribosomes are assembled (in nucleolus)
Capital N
Close parenthesis
Changed “turned into” to reflect production not magic!

19. Organelles Peroxisomes neutralize potentially dangerous
molecules within the cell.
Lysosomes digest and
recycle the cell’s used
components.
Relate H2O2 Is this info more than they need?

20. Organelles Cytoskeleton supports and shapes cell
helps position and transport organelles
provides strength
assists in cell division
aids in cell movement
Microfilaments
cell movement and muscle contraction
Microtubules
Form spindle fiber when cell divides
provide support
Flagella or Cilia
Used for movement.
Movement in single-celled organisms
Line respiratory tract in mammals
Sperm cells
Supports=support?
; rather than , after “cell divides”
Does red show up well enough??
Pix of 9+2

21. The organelle used for structure and support is the
cilia
cytoskeleton
flagella
nucleus

22. Plant cells Cell Wall Vacuoles Outside cell membrane
Made of cellulose (only in plants)
Used for support
Vacuoles
Plant cells have a central vacuole to store wastes and water; also helps support plant.
Picutre??
Cw = Not cellulose in bacteria either

23. Plant cells Plastids Chloroplast
Store starch or fats, or contain pigments
Chloroplast
Surrounded by double membrane and contain DNA
enable algae and plants to capture the energy in sunlight and use it to make sugars.
Membranes = double membrane

25. PLANT CELLS VS ANIMAL CELLS

26. Person B – What are three structures found in plant cell but not an animal cell?

27. Multicellular Organization
True multicellularity occurs only in eukaryotes
Multicellularity implies that different cells are using different genes.
In multicellular organisms, cells of common types are organized into tissues, which are organized into organs which are organized into systems
Example
Nerve Cellnerve tissuebrainnervous system
Systems in an organism interact to perform all of the functions necessary to life
Looks good!

28. DNA/Genetic Code Codes for proteins
Codes for our characteristics/traits

29. Protein Synthesis Central Dogma: DNA RNA Protein
RNA formation happens in the nucleus of the cell and is called transcription
Protein formation occurs in the ribosomes and is called translation.
mRNA – carries RNA out of the nucleus and to the ribosomes
tRNA – correctly aligns amino acids to form a protein. Has an anticodon that binds to a codon on the mRNA strand.

30. Protein Synthesis

31. Which one below is the correct sequence of the central dogma
RNADNAProtein
ProteinDNARNA
DNARNAProtein
DNAProteinRNA