Transcript ch7I and II-use this 1st

Chapter 7Cell Structure &
Function
I. Life is Cellular
A-The Discovery of the Cell
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•
It was not until the _________ that
scientists began to use microscopes to
observe organisms.
In 1665 ____________used an early
compound microscope to see tiny chambers
in cork.He called these chambers cells
after the tiny rooms in monasteries….we
know these not to be empty now.
Mid-1600’s
Robert Hooke
• About the same time in
Holland________________used a singlelens microscope to look @ pond water,
Anton van
Leeuwenhoek
• In 1838 Matthew Schleiden concluded
plants were made of cells
• 1839 Theodore Schwann said all animals
were made of cells
• 1855-Virchow said cells could only come
from existing ones.
These 3 things
compile_________________
– All living things composed of ___________
– Cells are the basic units of
___________________of living things
– New cells are produced from
______________________.
Existing cells
cells
Structure and
function
B-Exploring the Cell
•
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Florescent labels and light microscopy have
been used to follow molecules through the
cell.
_________________,which scans cells w/a
laser beam can make 3-d images of cells
Video technology make it possible to watch
cell growth , division and development
Confocal light
microscopy
• Light makes it difficult to visualize tiny
structures because it
scatters/______________________allow
things like proteins to be visualized (things
as much as 1000 x smaller can be
visualized….TEMS allow you to see
specimens cut into ultra thin slices
Electron
microscopes
• W/ a ______________specimens do not have
to be cut to see 3-D images….both must be
placed into a vacuum so air molecules do not
scatter electrons
• 1990’s____________________________have
revolutionalized visualization of surfaces and
atoms have been observed…can be used in
ordinary air and can show DNA structure
SEM
Scanning probe
microscopes
pollen
C .Prokaryotes and Eukaryotes
• Cells typically range from
_________micrometers,but some bacteria are .2
and some amoeba are 1000 micrometers
• All cells have 2 things in common:
» cell membrane-a barrier
» @ some point they contain_______
5-50
micrometers
DNA
2 broad categories:
– _____________________________genetic material is NOT contained in a
nucleus/generally less complicated than
other cells/carry out all cell
activities…present day members are
________________.
Prokaryotes
bacteria
•
_____________________________contain a nucleus w/ genetic
material,generally larger,much diversity
Eukaryotes
Division of Labor
Section 7-2
•A cell is made up of many parts with different
functions that work together. Similarly, the parts of a
computer work together to carry out different
functions.
•Working with a partner, answer the following
questions.
•1. What are some of the different parts of a computer?
What are the
functions of these computer
parts?
•2. How do the functions of these computer parts
correspond to
the functions of certain
cell parts?
Go to
Section:
Venn Diagrams
Section 7-2
Prokaryotes
Cell membrane
Ribosomes
Cell wall
Animal Cells
Lysosomes
Go to
Section:
Plant Cells
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Vacuoles
Mitochondria
Cytoskeleton
Cell Wall
Chloroplasts
Eukaryotes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
II. EUKARYOTIC CELL
STRUCTURE
• Organelles
• 2 major parts of eukaryotic cells
nucleus
cytoplasm
Specialized
structure that
performs important
functions within an
eukaryotic cell.
Cytoplasm is material
inside membrane and
outside nucleus
Figure 7-5 Plant and Animal Cells
Section 7-2
Smooth ER
Ribosome
(free)
Vacuole
Chloroplast
Ribosome
(attached)
Cell
Membrane
Nuclear
envelope
Cell wall
Nucleolus
Golgi
apparat
Mitochondrian
us
Nucleus
Rough ER
Plant Cell
Go to
Section:
Figure 7-5 Plant and Animal Cells
Section 7-2
Nucleolus
Nucleus
Nuclear
envelope
Ribosome
(attached) Ribosome
(freeCell
)
Membrane
Mitochondrian
Smooth
endoplasmic
reticulum
Rough
endoplasmic
reticulum
Centrioles
Golgi
apparatus
Animal Cell
Go to
Section:
The Nucleus
• Contains nearly all the cell’s DNA
• Codes for instructions to make proteins and
other molecules
• Surrounded by nuclear envelope---has many
pores to allow material in and out
• Contains chromatin—has DNA bound to
protein,usually spread throughout nucleus,but
condenses during cell division to make
CHROMOSOMES,containing genetic info
• Usually contain Nucleolus—assembly of
ribosomes begin here.
Ribosomes
• Proteins are assembled here
• Made out of small particles of RNA and
protein
• Found throughout cytoplasm
• Coded instructions from nucleus tell how
to make proteins
• Cells active in protein synthesis have a lot
of ribosomes
Endoplasmic Reticulum
• Site where lipid components of cell membrane
are assembled,along w/ proteins and other
materials exported from cell(those proteins are
made there)
• Rough ER is involved in protein
synthesis,because ribosomes are on it
• Newly made proteins leave ribosomes and insert
on rough ER ,where they may be modified
• If cell makes a lot of protein ,there is much ER
• Smooth ER may contain many specialized
enzymes
Lysosomes
• Small organelles filled w/enzymes
• May digest or break down lipids,carbs,and
proteins into small molecules that can be
used by the rest of the cell
• Lysosomes remove “junk”,or used up
organelles….very important that this
aspect function occurs
Vacuoles
• Sac like structures that store water ,salts
,proteins, and carbs
• Plants may have a single large water filled
vacuole
• Contractile vacuoles control water in
paramecium
Mitochondria and Chloroplasts
• Most all eukaryotic cells contain
mitochondria that convert chemical energy
stored in food into compounds convenient
for cell to use
• Mitochondria have an outer and inner
membranes
• In humans,nearly all mitochondria comes
from ovum(egg cell)
Chloroplasts
• Capture energy from sunlight and convert
into chemical energy in photosynthesis
• Contain 2 membranes and chlorophyll
Organelle DNA
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In chloroplasts and mitochondria
Small DNA molecules
Maybe descendants of early prokaryotes
----Endosymbiotic theory says these
prokaryoic ancestors developed a
symbiotic relationship w/ early eukaryotes
and resided within---evolving into
mitochondria
Cytoskeleton
• Network of protein filaments that help cell maintain
shape
• Also involved in movement
• MICROFILAMENTS are threadlike structures made of
a protein-actin….make a major network and a tough
framework///allows amoebas and such to move
• MICROTUBULES-hallow structures made of proteins
called tubulins—important in holding a cell’s shape---form a mitotic spindle in cell division/which helps
separate chromosomes
• CENTRIOLES are microtubules near nucleus in
animals and help organize cell division
• Microtubules also help make projections like cilia or
flagella
Figure 7-7 Cytoskeleton
Section 7-2
Cell membrane
Endoplasmic
reticulum
Microtubule
Microfilament
Ribosomes
Go to
Section:
Michondrion