1.
The Cell
CHAPTER 2 LESSON 2
P.51-58

2.
Vocabulary
•Cell membrane
•Cell wall
•Cytoplasm
•Cytoskeleton
•Organelle
•nucleus

3.
Outline
• Review Cells and
cell Theory
• Cell Shape
• Cell Types
– Pro/Eu
– Types of Eu cells
• Cell Parts
– Cell Membrane
– Cell Wall
– Cell Appendages
– Cytoplasm and
Cytoskeleton
• Cell Organelles
– Nucleus
• Chromosomes
• Nuclear envelope
– Ribosomes
– Rough ER
– Smooth ER
– Mitochondria
• ATP
– Chloroplasts
• Glucose
– Golgi Apparatus
• Vesicles
– Vacuoles

4.
Cells
• Smallest living unit
• Most are microscopic

5.
Cell Size

6.
Cell Diversity- ShapeCell Diversity- Shape
• Cells differ widely in shape.
• Size and shape relate to their
function.

7.
Principles of Cell Theory
• All living things are made of cells
• Smallest living unit of structure and
function of all organisms is the cell
• All cells arise from preexisting cells
(this principle discarded the idea of
spontaneous generation)

8.
Characteristics of All Cells
• A surrounding membrane
• cytoplasm – cell contents in thick fluid
• Organelles – structures for cell function
• Control center with DNA

9.
Cell Types
• Prokaryotic
• Eukaryotic

10.
Prokaryotic Cells
• First cell type on earth
• Cell type of Bacteria and Archaea
• Most are unicellular organisms
called prokaryotes

11.
Prokaryotic Cells
• No nucleus
• DNA floats freely in the cytoplasm
• No organelles, only free floating proteins

12.
Eukaryotic Cells
• Nucleus – DNA surrounded by a nucleus
• Include fungi, protists, plant, and animal cells
• Possess many organelles
• Much larger than prokaryotic cells
Protozoan

13.
Prokaryote vs. Eukaryote
• Pro = No nucleus
• Eu = Yes, there is a
nucleus

14.
Representative Animal Cell

15.
Representative Plant Cell

16.
Organelles
• In eukaryotic cells
• Cellular machinery
• Different functions

17.
Cell Membrane
• All cells
• Protects the inside of a cell from the outside
• Made of proteins and lipids called
phospholids

18.
Phospholipids
Protein

19.
Movement Across the Plasma Membrane
• Some things move freely in and out of the cell
• Some things are blocked and need proteins to
help them cross the membrane

20.
Cell Walls
• Found in plants, fungi, & many protists
• Surrounds plasma membrane
• Gives shape and support

21.
Cell Wall Differences
• Stiff structure
• Protects from viruses and other
harmful organisms
• Has holes that connect cell
membranes between cells

22.
Cytoplasm
• Fluid inside the cell
• Mostly water and salts
• Cytoskeleton
– Proteins that are the framework of a cell
– Like a skeleton or web of stick-like proteins
– Gives shape
– Helps the cell move

23.
Cell Appendages
• Help with movement
– Flagella – tail-like and whips back and forth
– Cilia – fine-hairs that move the cell or
molecules around it

24.
Nucleus
• Control center of cell
• Usually largest
organelle
• Double membrane
• Contains
– Chromosomes
– Nucleolus

25.
Nuclear Envelope
• Separates nucleus from rest of cell
• Double membrane
• Has pores

26.
Nucleolus
• Dark Spot in nucleus
• Forms ribosomes, organelle that makes
proteins

27.
DNA
• Hereditary material
• Chromosomes
– tightly wound DNA
• Humans have 23
pairs

28.
Endoplasmic Reticulum
• Helps move substances within cells
• Network of interconnected membranes
• Two types
– Rough endoplasmic reticulum
– Smooth endoplasmic reticulum

29.
Rough Endoplasmic Reticulum
• Ribosome are attached
• Spreads throughout the cell
• The site of protein production

30.
Ribosome
• Attached to the rough ER
– Make proteins
– Attached to rough ER or free floating
– Not surrounded my a membrane
– There are many in a cell

31.
Smooth Endoplasmic Reticulum
• No attached ribosomes
• Makes lipids such as cholesterol
– Carbohydrates
– Lipids

32.
Golgi Apparatus
• Involved in synthesis of plant cell wall
• Packaging & shipping station of cell

33.
Golgi Apparatus Function
1. Prepares proteins for their jobs
2. Packages proteins into vesicles

34.
Vesicles
• Many inside the cell
• After a protein is modified in the Golgi Apparatus
a vesicle pinches off containing the proteins
• Transport substances
• Tiny balls of membrane

35.
Lysosome
• Specialized Vesicle
• Full of enzymes, proteins that break down
and recycle cell components like old
proteins
• Tiny membrane ball
• Many

36.
Vacuoles
• Membrane bound storage sacs
• Plant cells have one large one
• Animal cells have many small ones
• Contents
– Water
– Food
– wastes

37.
Energy Processing
Organelles
• Release & store energy
• Types
– Mitochondria
(release energy)
– Chloroplasts
(store energy)

38.
Mitochondria
• Hundreds sometimes thousands
• Bound by double membrane

39.
Mitochondria
• Break down fuel molecules (cellular respiration)
– Glucose
– Fatty acids
• Release energy
– ATP

40.
ATP
• Adenosine triphosphate
• High-energy molecule
• Fuel for cellular processes

41.
Chloroplasts
• In plant cells
• Membrane bound
• Uses light to make glucose from CO2 and
H2O

42.
Photosynthesis
• Takes place in the chloroplast
• Makes cellular food – glucose

43.
Review of Eukaryotic Cells

44.
Review of Eukaryotic Cells

45.
Cell Transport

46.
Cells Have Large Surface
Area-to-Volume Ratio

47.
Molecule Movement & Cells
• Passive Transport
• Active Transport
• Endocytosis
(phagocytosis & pinocytosis)
• Exocytosis

48.
Passive Transport
• No energy required
• Move due to gradient
– differences in concentration, pressure, charge
• Move to equalize gradient
– High moves toward low

49.
Types of Passive Transport
1. Diffusion
2. Osmosis
3. Facilitated diffusion

50.
Diffusion
• Molecules move to equalize concentration

51.
Osmosis
• Special form of diffusion
• Fluid flows from lower solute concentration
• Often involves movement of water
– Into cell
– Out of cell

52.
Solution Differences & Cells
• solvent + solute = solution
• Hypotonic
– Solutes in cell more than outside
– Outside solvent will flow into cell
• Isotonic
– Solutes equal inside & out of cell
• Hypertonic
– Solutes greater outside cell
– Fluid will flow out of cell

53.
Facilitated Diffusion
• Differentially permeable membrane
• Channels (are specific) help molecule
or ions enter or leave the cell
• Channels usually are transport proteins
(aquaporins facilitate the movement of
water)
• No energy is used

54.
Process of Facilitated Transport
• Protein binds with molecule
• Shape of protein changes
• Molecule moves across membrane

55.
Active Transport
• Molecular movement
• Requires energy (against gradient)
• Example is sodium-potassium pump

56.
Endocytosis
• Movement of large material
– Particles
– Organisms
– Large molecules
• Movement is into cells
• Types of endocytosis
– bulk-phase (nonspecific)
– receptor-mediated (specific)

57.
Process of Endocytosis
• Plasma membrane surrounds material
• Edges of membrane meet
• Membranes fuse to form vesicle

58.
Forms of Endocytosis
• Phagocytosis – cell eating
• Pinocytosis – cell drinking

59.
Exocytosis
• Reverse of endocytosis
• Cell discharges material

60.
Exocytosis
• Vesicle moves to cell surface
• Membrane of vesicle fuses
• Materials expelled

61.
End Chapter 5