Download Ch. 7 Notes: Cell Biology

Ch. 7 Notes:
Cell Biology
Sizes of living things
Early microscopists
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1665 Robert Hooke (English) coined the
term "cell" while looking at cork.
1675 Anton van Leeuwenhoek (Dutch)
Lens maker who first reported observations
of living cells which he called "animicules".
1831 Robert Brown (English) discovered
the nucleus of the cell.
Three German scientists propose “The
Cell Theory” in the 1800s
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Matthias Schleiden - Botantist reported that
all plants were composed of cells.
Theodor Schwann - Zoologist reported that
all animals were composed of cells.
Rudolf Virchow – Physician reported that all
cells came from pre-existing cells
Three parts of the cell theory
1.
2.
3.
All living things are composed of
cells.
Cells are the basic unit of structure
and function of all living things.
New cells are produced from living
cells.
Sizes
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Cells vary in size, but most are microscopic
Can be unicellular or multicellularUnicellular- one-celled organism. Very
versatile
Multicellular- many celled organism. These
are more specialized with a division of
labor.
Shape and function
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The shape and structure of a cell is closely
related to the function of the cell
Most cells can generally
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Secure food for energy
Remove waste
Obtain oxygen
Produce chemicals
Regulate water balance
Reproduce other cells
There are only two types of cells
Prokaryote
Eukaryote
Prokaryote vs. Eukaryote
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Prokaryotes contain
no membrane bound
structures. Circular
chromosomes, cell
walls made of
peptidoglycen,
smaller ribosomes,
and fixed flagella
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Eukaryotes contain
membrane bound
organelles. Linear
chromosomes, cell
walls made of
cellulose of chitin,
and flexible
microtubule flagella
or cillia.
Prokaryotic Cell
Prokaryote cell function and parts
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Cell wall-Protective out barrier
Capsule- attachment to surfaces and protcetion
Cytoplasm-water and nutrients that support the
structures inside the cell
Flagellum- for swimming and movement
Ribosome- for protein production
Nucleoid- area where the DNA is located
Mesosome
Only BACTERIA are considered
prokaryotes.
Eukaryote Cell
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The eukaryotic cell contains
Boundaries- for protection
Organelles- for assembly, transportation,
and storage of cellular products, as well as
cellular support, locomotion and
reproduction.
Organelle
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Structures that perform a specific function in
certain cells.
Some organelles have membranes, but
eukaryotic cells are the only ones with organelles
with membranes.
List of organelles:
Nucleus, mitochondria, cell membrane,
lysosomes, chloroplast, ribosomes, golgi
apparatus, smooth and rough endoplasmic
reticulum, cytoplasm, vacuole, chloroplasts,
centrioles, cell wall, nucleolus.
Differences in Eukaryote Cell
Plant
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Cell wall, plastids, central
water vacuole
Animal
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Centrioles, lysosomes
Boundaries of a Eukaryote
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Plasma Membrane (aka cell membrane)
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Surrounds the cell and controls what enters and
leaves it.
Made of a phosopholipid bilayer with proteins
embedded in it. This fluid mosaic structure allows
for the membrane to be flexible
The cell is covered by an extracellular matrix
made up of glycocalyx.
Cell wall
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Aids in the protection and support of the cells
Made in a series of steps
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Middle lamella- a partition containing pectin
Primary wall- cellulose added to the middle lamella. Flexible and can
stretch with the growing cell
Secondary wall- cellulose and lignin added to the primary wall.
Inflexible
Fungus cell walls are made of chitin
The control-Cell nucleus
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Surrounded by a porous double bilipid membrane
Controls the cells activities by regulating the building of
proteins, which in turn regulates the cell chemical
processes and contains:
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DNA- master instructions for building proteins. Combines
with structural proteins to form chromatin, which is tightly
coiled during cell division in the form of chromosomes
RNA- copy of the master instructions to be used in the
actual building of a protein in the cytoplasm
Nucleolus- produces ribosomes (sites of protein
synthesis)
Assembly, Transport, and Storage
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Protoplasm
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Cytoplasm- jelly-like substance inside the cell
membrane by outside the nucleus. Various
organelles are suspended in it
Nucleoplasm- jelly-like substance inside the
nucleus
Endoplasmic Reticulum
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A network of membranes of membranes
that form a series of channels throughout
the cytoplasm. The cavity is used for
storage, separation, and transport
Endoplasmic Reticulum
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Two Types
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Rough and Smooth
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Rough ER- contains ribosomes attached to the
membranes. Important in the synthesis of proteins
for export from the cell and for use in the cell
membrane
Smooth ER- does not contain ribosomes. Used for
synthesizing lipids.
Ribosomes
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Structures made up of protein and RNA
where proteins are assembled
Ribosomes are located in two areas within
a cell
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Free- ribosomes that float in the cytoplasm and
all proteins made are directly used by the cell.
Attached- bound to the rough endoplasmic
reticulum.
Golgi Apparatus
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Stacks of membrane used to modify, store,
and package proteins and lipids
Proteins made in the endoplasmic
reticulum are transported and repackaged
to be sent to another part of the cell or a
new cell.
Vacuoles
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A membranous saclike structure used for
storage and excess water.
In the plant cell it comprises a major portion
of the cell, but in animal cells, they are
much smaller.
Lysosomes
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Membrane bound organelles formed by the
golgi apparatus and are used for breaking
down large molecules within the cell by
using digestive enzymes.
Energy Transformers
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Mitochondria and plastids are used by cells
to transform molecules into usable energy
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Mitochondria- double membrane. Used by the
cell to convert food energy into ATP
Plastids- double membrane. Found in plants and
are used in storage and food production
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Chromoplast- plastids that contain pigment
Leucoplast- plastids that store starch
Cholorplast- convert solar energy into food energy
Energy Transformers
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Mitochondria
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Chloroplast
Structural support and locomotion
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Cytoplasm support
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Microtubules- hollow-tube like. Make flagella,
cytoskeleton, centrioles, cilia, spindle fibers
Microfilaments- solid rods. Make cytoskeleton
and contract muscles.
Locomotion
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Cilia-hair-like projections
Flagella- tail-like projection used by whipping
back and forth
Pili- hair-like projections
Centrioles, Centrosomes
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Centrioles- used during cellular division by
the animal cell
Centrosome- used during cellular division by
both animal and plant cell. Plant cells
however have no centrioles
Organelle
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Specialized structure that performs a
specific function in certain cells.
Found in eukaryotes ONLY
List of organelles:
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Nucleus, mitochondria, cell membrane,
lysosomes, chloroplast, ribosomes*, golgi
apparatus, smooth and rough endoplasmic
reticulum, cytoplasm, vacuole
Nucleus
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A membrane-covered
organelle that contains
a cell’s genetic
information (genes).
Not all living cells have
nuclei.
Picture of a prokaryote
Eukaryotes do have membranes
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Eukaryotes have a nucleus. Their genetic
material is enclosed in a membrane-bound
organelle.
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Eukaryotes have membrane-bound
organelles, including a nucleus.
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If a cell has a nucleus, it is a eukayote;
Prokaryotes and eukaryotes
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Prokaryote: All bacteria are prokaryotes.
They have no nuclei.
Eukaryotes: Animals, plants, protists (like
amoeba and algae), and fungi (yeast, mold,
mushrooms, etc.) are all eukaryotes. They
all have membrane-bound organelles.
Example of an animal cell:
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Eukaryotic cells
Small vacuoles
No cell walls
Centrioles
No photosynthetic organelles
Example of an animal cell
Example of a plant cell:
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Eukaryotic cells
Large vacuoles
Have cell walls
No Centrioles
Photosynthetic organelle = chloroplast
Plant cell anatomy
Your Turn
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Fill in the blanks for your copy of the plant
and animal cells and then make
Make flashcards of the organelles
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Eukaryotes:
Have a nucleus. Animals, plants, protists
(like amoeba and algae), and fungi (yeast,
mold, mushrooms, etc.) are all eukaryotes.
They all have membrane-bound organelles.
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Two types:
Plant and animal cell
Why is there a distinguished difference?
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Example of an animal cell:
Eukaryotic cells
Small vacuoles
No cell walls
Centrioles
No chloroplast
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Example of a plant cell:
Eukaryotic cells
Large vacuoles
Have cell walls
No Centrioles
Chloroplast
Prokaryote cells: nucleiod
region, bacteria, no
nucleus
Cell wall
Plant cells
contain: cell wall,
chloroplast,
producers,
photosynthesis,
large central
vacuole,
Flagella,
cilia, pilli
Living, ribosomes,
cytoplasm, DNA,
RNA, proteins
Golgi apparatus, r & s
endoplasmic
reticulum, lysosome,
mitochondria,
nucleolus, nucleus,
Animal cells: cell
membrane,
heterotrophs
(consumers),
motile,