1. “We, all of us, are what happens when a primordial mixture of hydrogen and helium evolves for so long that it begin to ask where it came from”
-Jill Tarter
Life’s home: The Cell
Chapter 4

2. Cell Theory All living organisms are composed of cells
Unicellular or multicellular
Cells come from _______ cells
Modern additions to the theory
All cells use energy and have a metabolism
All cells have similar chemical composition
All cells have genetic information in the form of DNA

3. Cells are Specialized Over ____ different cells in the human body
You are made of trillions of cells!!
Reproductive cells
Red blood cell
Cardiac muscle cells
Bone cells
Nerve cell

4. Why so small? Surface area to volume ratio!
Greater surface area means greater ________
Transporting stuff into and out of the cell

5. Two Main Groups of Cells
Prokaryotic
(Bacteria and Archaea)
Eukaryotic
(Protists, Plants, Animals and Fungi)
*Not to scale

6. Prokaryotic and Eukaryotic Cells
Prokaryotic cell

7. Size of Prokaryotic Cells

8. Domains of Life Bacteria Archaea Eukarya Unicellular prokaryotes
Extremophiles
Eukarya
Unicellular and __________ eukaryotes
Protists
Fungi
Plants
Animals

10. Domain: Bacteria Prokaryotic cells
No membrane bound nucleus or organelles
Single-celled organisms
Asexual reproduction
___________ in cell wall separates bacteria from archaea

11. Domain: Archaea
Prokaryotic cell but similar to Eukaryotes in DNA replication and Protein synthesis
More closely related to ___________
______________: organisms that live grow best in one or more conditions that would kill most organisms
Thermophiles: live in extremely hot environments
Halophiles: live in extremely salty environments
Methanogens: Methane releasing archaea that are poisoned by oxygen

12. A Borrowed Life
Virus: an infections particle incapable of replicating outside of a cell, which consists of an RNA or DNA genome enclosed in a protein coat (capsid)
________________ parasites
Arguments for describing viruses as non-living
Can not __________ outside of host cell
Can not carry out ________________ outside of host cell
Lack ribosomes and enzymes
HIV attacking a white blood cell

13. Prokaryotic Cells
Pili: attachment structures on the surface of some prokaryotes
________: location of cell’s DNA (not enclosed in a membrane)
Ribosomes: site of protein synthesis
Cell wall: rigid structure outside of cell membrane
Bacterial
chromosome
____________: sticky outer coating on many prokaryotes
A typical
rod-shaped
bacterium
Flagella: locomotion organelles in some bacteria
A thin section through the
bacterium Bacillus coagulans

14. Eukaryotic Cells

15. Prokaryotic Reproduction
____________: DNA replicates and then the cell divides into two separate cells

16. Prokaryotic and Eukaryotic Cells
Characteristics
Prokaryotic Cells
Eukaryotic Cells
Cell Size
Small (0.2 – 2.0 µm in diameter)
Large (10 – 100 µm in diameter)
Organization
Always single celled
Often _________________
Nucleus
_________________ or nucleus, Nucleoid
Membrane bound nucleus
Membrane-enclosed organelles
___________
Present (e.g. lysosomes, Golgi complex, mitochondria)
Cytoplasm
No cytoskeleton or cytoplasmic streaming
Cytoskeleton, cytoplasmic streaming
Ribosomes
Present, smaller size
Present, larger size
Chromosomes (DNA)
Usually _______________ chromosome
_______________ chromosomes
Cell division
Binary fission
Involves mitosis
Sexual Recombination
None, transfer of DNA only
Involves meiosis

17. Major Components of Eukaryotic Cells
Nucleus: membrane bound region that contains the cell’s DNA
Organelles: highly organized structure in the cell that performs a specific cellular function
Cytosol: protein rich, jelly-like fluid in which the organelles are immersed
Cytoskeleton: internal supports of the cell made up of protein fibers
Plasma membrane: a complex, ___________ membrane that encloses the cytoplasm and regulate passage of ions and molecules into and out of the cell
Nucleus
Other organelles
Cytosol
Cytoskeleton
Plasma membrane

18. Origin of Organelles
Autogenesis: _______ of prokaryote plasma membranes lead to compartmentalization
Endoplasmic reticulum, golgi, nuclear membrane
_________________: one organism lives inside the cell of another organism
Mitochondria, chloroplasts
Endosymbiosis
Autogenesis
Endosymbiosis

19. Specific Functions of Organelles

20. The Nucleus Control center of the cell Stores DNA Nuclear membrane
Chromatin: uncoiled DNA
______________: coiled DNA containing genes
Nuclear membrane
Contains pores
Nucleolus: region inside nucleus where ribosomal subunits in manufactured
Chromosome
DNA
Nucleus
Nucleolus
Gene

21. Endomembrane System
Rough endoplasmic reticulum: network of membranes that aid in protein processing
Studded with ___________
Smooth endoplasmic reticulum: network of membranes that functions in the synthesis lipids and ___________ of harmful molecules including alcohol, drugs and metabolic wastes.
Lacks ribosomes

22. Golgi Complex Protein processing and distribution
_____________ determine shipping route

23. Lysosomes _______ old cellular products and foreign material
Cell “digestive system”
Recycles useable molecules
Go on to form new organelles
Found in _______ cells

24. Protein Production Summary

25. Protein Production: Step 1
______________: process in which a section of DNA is copied onto messenger RNA (mRNA)
RNA polymerase
mRNA
DNA
Direction of transcription

26. Protein Production: Step 2
Translation: process by which a __________ is produced in a ribosome from information encoded within a messenger RNA

27. Mitochondria
Creates Adenosine Triphosphate (ATP) from food (cellular respiration)
ATP = cellular energy
Requires macromolecules from food and O2, expels CO2
Breakdown generates _____ (metabolic heat)

28. Cell Cytoskeleton
Aids in cell structure, cell movement and transport of materials within cell
Made up of three types of protein fibers
Microfilaments: solid, rod-like fibers that aid in cell division and changes in cell shape
Intermediate filaments: rope-like structures that give the cell strength and maintain cell shape
___________: long hollow tubes that aid in the movement of molecules and organelles throughout the cell

29. Cell Movement Modified microtubules
____: short, hair-like projections often found in large numbers on the exterior of the cell.
Used for locomotion or movement of fluid around a cell.
Flagella: long, tail-like extension used for locomotion.
Typically one per cell

30. Plant and Animal Cells

31. Plant and Animal Cells
Animal Cell
Plant Cell
Both

32. Plant Cells: Chloroplasts
Contain chlorophyll (photosynthesis)
Endosymbiosis
Thylakoid

33. Plant Cells: Central Vacuole
Maintains cell pressure
Stores __________
Degrades cell waste products
Large central vacuole

34. Plant Cells: Cell Wall
_________: polysaccharide that is a main structural component of cell walls
Limits water absorption
Structural strength

35. Cell Communication Plant Cells
Plasmodesmata: channels between plant cell walls
Creates continuous cytoplasm
Do not open and close

36. Cell Communication Animal Cells
Gap junctions: protein assemblage that forms a communication channel between adjacent animal cells
Open and close as needed