cell-cell biology
TRANSCRIPT
-
7/27/2019 Cell-cell biology
1/22
A Tour of the Cell
Chapter 6
-
7/27/2019 Cell-cell biology
2/22
Objectives
Be familiar with the regions of the cell andthe overall role of each region
Be familiar with the basic organelles and
their function
Be familiar with the way neighboring cells
can communicate
-
7/27/2019 Cell-cell biology
3/22
Cell Types
All living organisms
are made of cells Two kinds of cells
Prokaryotic: lacks
membrane boundstructures other than
plasma membrane
Bacteria
Eukaryotic: contains
membrane bound
organelles enablingcompartmentalization
leading to
specialization animals, plants, protists,fungi
-
7/27/2019 Cell-cell biology
4/22
Cell Size
Limits on cell sizedetermined by ability
to perform metabolic
processes Lower: can all
necessary components
fit Upper: can we regulate
supplies adequately
(surface to volumeratio)
-
7/27/2019 Cell-cell biology
5/22
Regions of a Eukaryotic Cell
Nucleus: contains genetic material (DNA)necessary for cell regulation. Reference
library
Cytoplasm: consists of cytosol (cell fluid)
and organelles (specialized structures that
carry out metabolic activities of cell) Plasma Membrane: contains the cell and
regulates movement of materials into/out ofthe cell
-
7/27/2019 Cell-cell biology
6/22
Cell Overview
-
7/27/2019 Cell-cell biology
7/22
Nucleus
Control center of cell Dual membrane
system that fuse to
form nuclear pores DNA and Protein
complexes called
Chromatin
Nucleolus: region of
RNA within theNucleus
-
7/27/2019 Cell-cell biology
8/22
Nuclear Pore Structure
To get materials into the
nucleus there is a 27
Amino Acid tag (zip code)
added onto molecules and
are assisted by proteinscalled importins
To leave the nucleus
exportin proteins, aspecific zip code, GTP
and Ran are required
-
7/27/2019 Cell-cell biology
9/22
Import Summary
-
7/27/2019 Cell-cell biology
10/22
Ribosomes
Sites of Proteinsynthesis
May be free or bound
Free make proteinstypically used in the
cell
Bound are attached tomembrane (ER) and
make proteins typically
for export
-
7/27/2019 Cell-cell biology
11/22
Endoplasmic Reticulum (ER)
Part of theendomembrane system
Smooth ER: site of
lipid synthesis, detox,carbohydrate
metabolism
Rough ER: site of
protein synthesis
(contains bound
ribosomes)
-
7/27/2019 Cell-cell biology
12/22
Golgi ApparatusWhen it absolutely, positively, has to leave the cell
Finishes, sorts, andpackages
manufactured products
of the cell cis: receives products
from ER
trans: ships materials
to other parts of cell
(often the plasma
membrane)
-
7/27/2019 Cell-cell biology
13/22
Lysosomes
Membrane boundstructures responsible
for the degradation of
spent organelles andfood items
Contain hydrolytic
enzymes
-
7/27/2019 Cell-cell biology
14/22
Vacuoles
Membrane bound
storage areas for
resources
Named after theresource they contain
-
7/27/2019 Cell-cell biology
15/22
Mitochondria, Chloroplast
Mitochondria: site of
most ATP synthesis
Chloroplast: site of
carbohydrate synthesis
-
7/27/2019 Cell-cell biology
16/22
Peroxisomes
Modify molecules
through redox
reactions (fatty acid)
Produce peroxide as aresult (H2O2)
Split into two as they
grow
-
7/27/2019 Cell-cell biology
17/22
Cytoskeletal
elements
Provide structuralframework for the cell
Movement of materialsinside and on the surface ofthe cell
Microtubules
grow from centrosome
load bearing Microfilaments
pulling forces
Intermediate filaments pulling forces
-
7/27/2019 Cell-cell biology
18/22
Organelles of Motility
Flagellum: moves the entire cell
Cilium (cilia): moves things along the surface of
the cell
-
7/27/2019 Cell-cell biology
19/22
Extracellular Surfaces
Most cells have a
combination of proteins,
lipids and sugars that form
an extracellular matrix Plants have a cell wall
-
7/27/2019 Cell-cell biology
20/22
What distinguishes one cells
function from another?
The quantity and type
of organelles
determine how the cell
can function.
-
7/27/2019 Cell-cell biology
21/22
Communication is Critical Connections between cellsare called junctions
Tight junctions: leak-proof connections
between cells
Desmosomes: fastencells together
strengthening the tissue
Gap junctions:provide cytoplasmic
channels between cells
Plasmodesmata: plantcell channels
In order for many cells to
function as a unit (as in
multicellular organisms)there must be a minimal
level of communication
-
7/27/2019 Cell-cell biology
22/22