1. Life is based on chemistry, and chemistry takes place in cells
The Living Cell
Life is based on chemistry, and chemistry takes place in cells

2. Outline The Nature and Variety of Cells How Does a Cell Work?
Metabolism: Energy and Life
Cell Division

3. The Nature and Variety of Cells

4. The Cell Theory All living things are composed of cells
The cell is the fundamental unit of life
All cells arise from previous cells

5. Observing Cells: The Microscope

6. How Does a Cell Work?

7. Cell Membranes Cell Membranes Transport Receptors Cell Wall
Isolate cell
Separates cell parts
Transport
Individual molecules
Specific materials
channels
Receptors
Bind molecules
Cell Wall
Plants

8. Plant Cell

9. There are two types of cells on Earth: Prokaryotic and Eukaryotic
There are two types of cells on Earth: Prokaryotic and Eukaryotic. The former appeared first, and strong evidence indicates that the latter evolved from the former via endosymbiotic relationship.
Prokaryotic cells include all bacteria and the blue-green algae. Fossil evidence shows that they have lived on earth for at least 3.8 billion years.
The DNA in prokaryotic cells is not enclosed within a membrane-bound nucleus as is the DNA in eukaryotic cells.

10. Schematic of a Eukaryotic Cell
The information required for producing all of the constituents of a cell is contained in the DNA in the chromosomes in the nucleus

11. The Nucleus Nucleus Prokaryotes Eukaryotes Double Membrane
Contains genetic material
Prokaryotes
No nucleus
Eukaryotes
Double Membrane

12. Cell, the factories of life
You have about 10 trillion cells.
Factories have:
Front office- paperwork
Building- Bricks and Mortar- loading docks
Production Units
Power Plant

13. Cell, the factories of life
Paperwork- the plan- DNA
Building- cell walls.
Protein & Receptors- loading dock

14. Cell, the factories of life
Production- organelles- perform the chemical functions
Power Plant- Mitochondria receive carbohydrates, fats and proteins and “burn” to produce energy
Synthesis- site of protein synthesis (controlled by RNA next chapter)

15. Photograph of a cell of maize rust
Photograph of a cell of maize rust. The dark boundary is the cell wall, made from cellulose. The nucleus takes up almost half the area of the central part of the cell.

16. Mitochondria
“Sausage“ shaped organelles (specialized structures in cells) where molecules derived from glucose react to produce the cells energy

17. An organelle- mitochondria.

20. The Energy Organelles: Chloroplasts and Mitochondria
Specialized structure in cell
Chloroplasts
Energy transformation
chlorophyll
Plant cells only
Double membrane
Mitochondria
Produces cells energy
Own DNA

21. Cytoskeleton Cytoskeleton Structure Gives cell shape Anchors
Allows movement
Transport system
Within cell
Structure
Strong filaments
Complex web

22. Metabolism: Energy and Life

23. Cells Energy Cells store energy in various ways.
The most common is in a molecule adenosine triphosphate or ATP.
Making ATP is endothermic so cells can make ATP and then release that energy when it’s needed.

24. The Cell’s Energy Currency
Adenosine triphosphate (ATP)‏
Provides energy
Structure
3 phosphate groups
Sugar molecule:
ribose
adenine
Function
Removal of phosphate group provides energy

25. The ATP reaction
The tri-phosphate becomes a di-phosphate

27. Photosynthesis Photosynthesis Process Colors
Convert sunlight to energy
Process
Energy + CO2 + H2O carbohydrate + O2
Colors

28. Glycolysis: The First Step in Energy Generation in the Cell
Respiration
Oxidation of carbohydrate
Retrieves energy in glucose
Aerobic
Process
Glycolysis
Split glucose
Result
Pyruvic acid
2 ATP
2 energy carriers
Convert energy carriers to 2-3 ATP
1 molecule glucose = 6-8 ATP

29. Fermentation: A Way to Keep Glycolysis Going
Anaerobic
Inefficient
Yeast
alcohol
Animal cells
Lactic acid

30. The Final Stages of Respiration
Krebs cycle
Glucose broken down
CO2 produced
ATP
Energy-carrying molecules
Result
36-38 ATP

31. Cell Division

32. Mitosis Mitosis Chromosomes Process Cell division
Not for sexual reproduction
Chromosomes
Process
Copy chromosomes
Spindle fibers
Migration of chromosomes
Nuclear membrane reforms

34. Meiosis Meiosis Process Result Sexual reproduction
1 cell forms 4 gametes
Gametes are genetically unique
Process
Copy chromosomes
Crossing over
Segregation
Segregation again
Result
4 daughter cells
½ normal chromosomes

35. Meiosis

36. VIRUS
Virus occupy a twilight zone between the worlds of living and nonliving things. Criteria commonly applied for living things include (1) independent motility, (2) irritability (the ability to respond to certain environmental stimuli), (3) the ability to reproduce, and (4) the ability to specify the genetic composition of progeny.

37. Viruses can have a wide variety of shapes and sizes
Viruses can have a wide variety of shapes and sizes. This diagram of a bacterial virus shows the protein coat containing DNA at the head. The tail fibers at the bottom attach the virus to the cell wall. DNA is then injected into the cell through the cylindrical core.

38. A diagram of the HIV virus
A diagram of the HIV virus. The reverse transcriptase is the enzyme that initiates reverse transcription in the virus.

39. THE AIDS VIRUS
Human immunodeficiency virus (HIV) was shown in 1984 to be the cause of the dreaded condition called immune deficiency syndrome (AIDS).
In 2004
40 million people lived with it (1.1 million Americans)
5 million people acquired HIV
3.1 million people died of it

40. The central dogma of molecular biology

41. HIV is a human retrovirus, the third such virus to be identified
HIV is a human retrovirus, the third such virus to be identified. Retroviruses (retro--from Latin means "turning back" are named after the crucial step in their growth cycle that involves the reversal of transcription, the first half of the "central dogma of biology"

42. Organic Molecules

43. Four Basic Characteristics
Most molecules based on chemistry of carbon
Organic molecules
Life’s molecules form from few elements
H, O, C, N97.5% of body weight
Molecules composed of simple building blocks
Arranged differently
Shape determines behavior
Determines ability for bonding

44. Chemical Shorthand No H atoms or bonds to H are shown
C atoms are not shown explicitly
Shorthand