CHAPTER 6 A TOUR OF THE CELL Cytology: science/study of cells Light microscopy resolving power~...
-
Upload
daniella-stevenson -
Category
Documents
-
view
218 -
download
0
Transcript of CHAPTER 6 A TOUR OF THE CELL Cytology: science/study of cells Light microscopy resolving power~...
CHAPTER 6A TOUR OF THE CELL
Cytology: science/study of cells
Light microscopy resolving power~ measure of clarity
Electron microscopy
TEM ~ electron beam to study cell ultrastructure
SEM ~ electron beam to study cell surfaces Cell fractionation ~ cell separation; organelle study Ultracentrifuge ~ cell fractionation; 130,000rpm
A cell is a living unit greater than the sum of its parts
• While the cell has many structures that have specific functions, they must work together.
AP Biology
Prokaryotebacteria cellsProkaryote
bacteria cellsTypes of cells
Eukaryoteanimal cellsEukaryote
animal cells
- no organelles
- organelles
Eukaryoteplant cellsEukaryoteplant cells
Cell Types: Prokaryotic
Nucleoid: DNA
concentration
No organelles with
membranesRibosomes:protein synthesis
Plasma membrane: (all
cells); semi-permeable
Cytoplasm/cytosol(all cells)
Cell types: Eukaryotic
Nucleus:membrane enclosed organelle containing chromosomes
Membrane bound organelles of specialized form and function
Generally larger than prokaryotic cells
Cell Size
As cell size increases, the surface area to volume ratio decreases
Rates of chemical exchange may then be inadequate for cell size
Cell size, therefore, remains small
AP Biology
Why organelles? Specialized structures
specialized functions cilia or flagella for locomotion
Containers partition cell into compartments create different local environments
separate pH, or concentration of materials distinct & incompatible functions
lysosome & its digestive enzymes
Membranes as sites for chemical reactions unique combinations of lipids & proteins embedded enzymes & reaction centers
chloroplasts & mitochondria
mitochondria
chloroplast
Golgi
ER
AP Biology
Cells gotta work to live! What jobs do cells have to do?
make proteins proteins control every
cell function make energy
for daily life for growth
make more cells growth repair renewal
AP Biology
Proteins do all the work!
cellscells
DNADNA
proteinsproteins
organismorganismRepeat after me…
Proteins do all the work!
AP Biology
Cells functions Building proteins
read DNA instructions build proteins process proteins
folding modifying
removing amino acids adding other molecules
e.g, making glycoproteinsfor cell membrane
address & transport proteins
AP Biology
Building Proteins Organelles involved
nucleus ribosomes endoplasmic reticulum
(ER) Golgi apparatus vesicles
nucleus ribosome ERGolgi
apparatusvesicles
The Protein Assembly Line
AP Biology
nuclearpores
nuclearpore
nuclear envelopenucleolus
histone protein
chromosome
DNA
Function protects DNA
Structure nuclear envelope
double membrane membrane fused in spots to create pores
allows large macromolecules to pass through
Nucleus
What kind of molecules need to
pass through?
AP Biology
AP Biology
Nucleolus Function
ribosome production build ribosome subunits from rRNA & proteins exit through nuclear pores to cytoplasm &
combine to form functional ribosomes
smallsubunit
large subunit
ribosome
rRNA &proteins
nucleolus
AP Biology
smallsubunit
largesubunitRibosomes
Function protein production
Structure rRNA & protein 2 subunits combine 0.08m
RibosomesRough
ER
SmoothER
AP Biology membrane proteins
Types of Ribosomes Free ribosomes
suspended in cytosol synthesize proteins that
function in cytosol
Bound ribosomes attached to endoplasmic
reticulum synthesize proteins
for export or for membranes
AP Biology
Endoplasmic Reticulum Function
processes proteins manufactures membranes synthesis & hydrolysis of many compounds
Structure membrane connected to nuclear envelope &
extends throughout cell
AP Biology
Types of ER
rough smooth
AP Biology
Smooth ER function Membrane production Many metabolic processes
synthesis synthesize lipids
oils, phospholipids, steroids & sex hormones
hydrolysis hydrolyze glycogen into glucose
in liver
detoxify drugs & poisons in liver ex. alcohol & barbiturates
AP Biology
Membrane Factory Build new
membrane synthesize
phospholipids builds membranes
ER membrane expands bud off & transfer
to other parts of cell that need membranes
AP Biology
Rough ER function Produce proteins for export out of cell
protein secreting cells packaged into transport vesicles for export
Which cellshave lot of rough ER?
AP Biology
Golgi Apparatus
AP Biology
Vesicle transport
vesiclebuddingfrom roughER
fusionof vesiclewith Golgiapparatus
migratingtransportvesicle
protein
ribosome
AP Biology 2007-2008
Any Questions!!