Chapter 7A View of the Cell: ARE THOSE OUR CELLS?.
-
Upload
francis-williamson -
Category
Documents
-
view
226 -
download
1
Transcript of Chapter 7A View of the Cell: ARE THOSE OUR CELLS?.
Chapter 7A View of the Cell: ARE THOSE OUR
CELLS?
Smallest unit that can carry out all the activities necessary for life.
Can survive on its own or has potential to do so
Is highly organized for metabolism
Senses and responds to environment
Has potential to reproduce
Section 7.1 Cell:
Anton Von Leeuwenhoek, the first person to observe "animalcules" through a microscope, didn’t at all like what he saw.
Fig. 4.1, p. 50-51
ROBERT HOOKE— “Cells”crude compound micriscope
The Cell Theory
Electron Microscopes
1930’s
Uses a beam of electrons
to magnify to to 500,000 X
Cell surfaces; internal
structures
CELL DIFFERENCES
Size; Shape; Types and number of Internal StructuresExample: muscle cells have a lot of __________________ for ATP production (high energy needs)
SIMILARITIES
Functionally
Two Basic Cell Types
1. Prokaryotes No Nucleus No internal membrane-bound organelles Bacteria (2 Kingdoms)
2. Eukaryotes Have internal membrane –bound organelles. Other 4 kingdoms. (Animalia, Plantae, Protista,
Fungi)
7.2 The Plasma MembraneSelectively permeable Water and small molecules like O2, CO2 , and nonpolar
molecules --freely pass through.
Charged particles (like ions) and large molecules need special assistance (proteins assist movement)
-------------------------------------------- Try an analogy---- -----------------------------------------------
.
animation
Click to view animation.
Plasma Membranes
Phospholipids-Polar “head” and 2 non-polar tails
Main component of membranes
Gives the membrane its fluid properties
Two layers of phospholipids-end to end.
The cell membrane's function, in general, revolves around is membrane proteins. General functions include: Receptor proteins which allow cells to communicate, transport proteins regulate what enters or leaves the cell, and marker proteins which identify the cell
The Phospholipid Bilayer
Polar and Nonpolar regions
A mosiac
The Fluid Mosaic Model
A mosaic of materials Phospholipid bilayer Proteins Cholesterol
Fluid—because the phospholipids are unsaturated. Some of the proteins are free to move within the
membrane too
Functions of Membrane Components
Cholesterol—give it some stability.
Transport ProteinsHelp regulate entry and
exit of molecules and ions.
Cell Surface Markers (have sugars attached). Attached to cell surface.Like a cell’s ID tag.
Class Work. May work with a partner, but each is to
complete this.P. 174
Draw prokaryotic cell, label cell components, color!!!
Same for the Eukaryotic cell.
How do they compare in size?
7.3 Eukaryotic Cell Structure
Cell Wall
Inflexible barrier.Support and protection
Porous—not selective
The Nucleus
1.Contains DNA—directions for making proteins Chromatin-thin; non-dividing cell
Chromosomes-compact, visible when cell is dividing
2. Nucleolus—this makes ribosomes.RNA forms, exits nucleus through Nuclear Pores to the CytoplasmNuclear Envelope
Cell functions
Like a candy factoryLots of ProductionNeed to move materials insideNeed to send Finished materials (candy) out to sell and waste productsMovement is regulated at the perimeter gate by security, allows controlled entry and egress.
HOMEWORK
READ 7.3
TERMS TO KNOW
Terminology in bold font-
describe
function
what organisms are they found in
Describe the advantage of highly folded membranes in cells.
Homework
1. Compare and contrast prokaryote and eukaryote cells.
2. Why are plasma membranes describes as a “fluid mosaic”?
What is the role of cholesterol in plasma membranes?
CELLS ARE LIKE LITTLE CANDY FACTORIES
Structure of Cells
Cell membrane FunctionCell Size is LimitedImportance of Water in formation of MembranePolar vs. Non-PolarHydrogen -Bonds
Cell Size is Limited
In most cases, a living thing grows because it produces MORE cellsAn adult simply has more cells than an infant, not simply larger cells.WHY more cells, not larger cells?Remember—Membrane Function…How fast exchange occurs depends upon the SURFACE AREA of the cellBUT, how quickly food & Waste are made depends on Cell Volume
animation
Click to view animation.
Plasma Membranes
1.Phospholipids-Polar “head” and 2 non-polar tails
Main component of cell membranes
Gives the membrane its fluid properties
Two layers of phospholipids
The cell membrane's function, in general, revolves around is membrane proteins. General functions include: Receptor proteins which allow cells to communicate, transport proteins regulate what enters or leaves the cell, and marker proteins which identify the cell
Phospholipid Bilayer up close and personal
Cell Membrane Proteins
How their structure related to their function in the membrane
2 types of CELLSEUKARYOTE VS.
PROKARYOTE Differences
AND
Similarities