Download Cells - KayWCHS

Biology 1- Chapter 7 Notes
Prentice Hall (pg. 168-193)
•
7–1
Life Is Cellular
•
A. The Discovery of the Cell
1. Early Microscopes
2. The Cell Theory
B. Exploring the Cell
C. Prokaryotes and Eukaryotes
1. Prokaryotes
2. Eukaryotes
•
7–2
A.
B.
C.
D.
E.
F.
G.
H.
Cell Boundaries
A. Cell Membrane
B. Cell Walls
C. Diffusion Through Cell Boundaries
1. Measuring Concentration
2. Diffusion
D. Osmosis
1. How Osmosis Works
2. Osmotic Pressure
E. Facilitated Diffusion
F. Active Transport
1. Molecular Transport
2. Endocytosis and Exocytosis
Eukaryotic Cell Structure
Comparing the Cell to a Factory
Nucleus
Ribosomes
Endoplasmic Reticulum
Golgi Apparatus
Lysosomes
Vacuoles
Mitochondria and Chloroplasts
1. Mitochondria
2. Chloroplasts
3. Organelle DNA
I. Cytoskeleton
7–3
•
7–4
The Diversity of Cellular Life
A. Unicellular Organisms
B. Multicellular Organisms
1. Specialized Animal Cells
2. Specialized Plant Cells
C. Levels of Organization
1. Tissues
2. Organs
3. Organ Systems
7.1: The History of the Cell Theory
• Before microscopes were invented, people
believed that diseases were caused by
curses and supernatural spirits.
• As scientists began using microscopes,
they quickly realized they were entering a
new world–one of microorganisms.
• Microscopes enabled scientists to view
and study cells, the basic units of living
organisms.
Development of Light
Microscopes
• The first person to record looking at water under a
microscope was Anton van Leeuwenhoek.
• The microscope van Leeuwenhoek used is considered a
simple light microscope because it contained one lens
and used natural light to view objects.
• Compound light microscopes use a series of lenses to
magnify objects in steps.
• These microscopes can
magnify objects up to
1500 times.
The Cell Theory
• Robert Hooke was an
English scientist who
lived at the same time as
van Leeuwenhoek.
• Hooke used a compound
light microscope to study
cork, the dead cells of
oak bark.
• He thought the structures
he observed resembled
the one room “cells”
• Hooke is credited with
giving cells their name
• Cells are the basic
building blocks of all
living things.
The cell theory is made up of three
main ideas:
1. All organisms are composed of one or more cells.
2. The cell is the basic unit of structure and function of
organisms.
3. All cells come from preexisting cells.
Three Scientists contributed to the Cell Theory:
• 1838- Schleiden: plants are made of cells
• 1839- Schwann: animals are made of cells
• 1855- Virchow: New cells are produced from the
division of old cells
Development of Electron
Microscopes
• The electron microscope
was invented in the 1940s.
• This microscope uses a
beam of electrons to
magnify structures up to
500,000 times their actual
size.
There are two basic types
of electron
microscopes.
• The scanning electron
microscope scans the
surface of cells to learn their
three dimensional shape.
• The transmission electron
microscope allows scientists
to study the structures
contained within a cell.
Scanning Probe Microscope
• Discovered in the
1990’s
• Produces images by
tracing the surfaces of
samples with a fine
probe
• Can observe single
atoms in the air or in
solution
SEM Picture
of Neuron
Condensed DNA by
Scanning probe
Two Basic Cell Types
Cell membrane
Cytoplasm
Prokaryotic Cell
Cell membrane
Cytoplasm
Nucleus
Eukaryotic Cell
Organelles
Prokaryotic and Eukaryotic Cells
Prokaryotic Cells
• Cells that do not
contain internal
membrane-bound
structures and do not
have a nucleus are
called prokaryotic
cells.
Prokaryotic
Cell
• Unicellular organisms
such as bacteria are
very simple.
• They still carry out all
of life’s activities such
as respiration, cell
reproduction, growth,
etc.
Eukaryotic Cells
• Cells containing
membrane-bound
structures and a
nucleus are called
eukaryotic cells.
• Most of the multicellular plants and
animals are made up
of cells that are very
specialized and
diverse in their
structures and
functions
Eukaryotic Cell
7.2 Eukaryotic Cell Structure
Organelles
• The membrane-bound
structures within eukaryotic
cells are called organelles.
• Each “little organ” has a
specific function that
contributes to cell survival.
• Separation of organelles into
distinct compartments
benefits the eukaryotic cells.
• Lysosomes
• Nucleus
• Plasma Membrane
• Endoplasmic Reticulum
• Mitochondrion
Biologists divide the cell into
two major parts
• The nucleus is the central
membrane-bound organelle that
manages cellular functions.
• Everything between the cell
membrane and the nucleus is
called the cytoplasm.
Nucleus
- Nuclear envelope – double layered membrane surrounding nucleus;
contains small pores
- Nuclear pores- allow transport of materials in and out of nucleus
- Chromatin-granular material visible within the nucleus; consists of
DNA tightly coiled around proteins
- Chromosomes – threadlike
Nucleolus
Chromatin
structure within the nucleus
containing the genetic
information that is passed
from one generation of cells
to the next (chromosomes are
formed when chromatin
condenses during cell division)
Nuclear
- Nucleolus – dense material
Envelope
in nucleus; makes
ribosomes which make
proteins
Nuclear Pore
Ribosomes
• Ribosomes are made in
the nucleolus.
• They travel in and out
of the nucleus through
the nuclear pores.
Ribosomes
• Ribosomes are small
particles within the cell
on which proteins are
assembled; made of
RNA and protein
• They can be free (in the
cytoplasm)
• They are also attached
to the rough endoplasm
reticulum
Endoplasmic reticulum
• The endoplasmic reticulum
(ER) is responsible for
assembly, transport, and
storage of molecules within
cell.
• There are two types
• Rough ER- contains
ribosomes and makes
proteins
• Smooth ER- lacks
ribosomes; has enzymes
that make membrane lipids
and detoxifies drugs
• Liver cells contain many
smooth ER for
detoxification
Golgi Apparatus
• Stacks of membranes
in the cell that
modifies, sorts, and
packages proteins
from the endoplasmic
reticulum
• The Golgi apparatus
is like a customization
shop where finishing
touches are added to
proteins.
Lysosomes
• Lysosomes are organelles that contain
digestive enzymes. They digest excess or
worn out organelles, food particles, and
engulfed viruses or bacteria.
• The lysosomes are the clean-up crew of the
cell
• Tay-Sachs disease is caused by excess lipid
accumulation on the brain. The cause of this
disease has been traced to lysosomes that
failed to function properly
Vacuoles
• Vacuoles are membrane-bound spaces used for
temporary storage of materials (such as water,
salts, proteins, and carbohydrates)
• Notice the difference between vacuoles in plant
and animal cells.
Plant
Vacuole
Animal
Cell
Cell
• Paramecium have a
contractile vacuole
that pumps excess
water out of the cell,
which aids with
homeostasis
Mitochondria
• Mitochondria are
• Cellular respiration is the
membrane-bound
process that converts
organelles in plant and
chemical energy stored in
animal cells that transform
food into ATP energy for
energy for the cell.
cells to use.
• A mitochondria, like the
• Muscles cells (needed for
endoplasmic reticulum,
has a highly folded inner
movement) contain a large
membrane.
number of mitochondria for
• The folds increase the
energy production
surface area of the
mitochondrion in order to
make more energy (ATP)
• Cellular Respiration takes
place in the mitochondria
of cells
Chloroplasts
• Chloroplasts are found in
cells of plants and some
other organisms
• Chloroplasts are organelles
that capture light energy
and produce food to store
for a later time.
• Photosynthesis takes place
in the chloroplasts
• Chloroplasts contain green
pigment called chlorophyll.
• Chlorophyll traps light
energy and gives leaves
and stems their green
color.
• Chloroplasts acts like a
solar power plant
Organelle DNA
• Lynn Margulis - described mitochondria and chloroplasts as
free-living aerobic prokaryotes which developed a partnership
with host cell; endosymbiosis hypothesis
• chloroplasts and mitochondria have their own circular DNA &
ribosomes, make their own proteins, reproduce on their own
Cytoskeleton
• Cells have a support structure called the
cytoskeleton within the cytoplasm.
• It is a network of proteins that help
maintain cellular shape and movement
• The cytoskeleton is composed of
microtubules and microfilaments.
Cell membrane
Endoplasmic
reticulum
Microtubule
Microfilament
Ribosomes
Mitochondrion
• Microtubules are
thin, hollow
cylinders made of
protein that
maintain cell
shape
• Microfilaments
are thin solid
protein fibers that
help cells move
(amoeba)
Centrioles
• Made of microtubules and cytoskeleton
• one of two tiny structures located in the cytoplasm of
animal cells near the nuclear envelope
• help to organize cell division (helps cells split into two)
• only found in animal cells
Cilia and Flagella
Cilia
• Some cell surfaces have cilia and flagella,
which are structures aid in locomotion or
feeding.
• Made of microtubules from the
cytoskeleton
• Cilia and flagella can be distinguished by
their structure and by the nature of their
action.
• Cilia are short, numerous, hair-like
projections that move in a wavelike
motion.
• Flagella are long projections that move in
a whip-like motion.
• Flagella and cilia are the major means of
locomotion in unicellular organisms.
Flagella
Microscope Lab
• Purpose :To compare the basic structures and shape of plant
and animals cells by looking at onion (epidermal) cells and
cheek (epithelial) cells
– epidermal cells- cells that make up the protective outer
covering of plants; tissue that covers the human body
– epithelial cells- cells that make up tissues that cover bodies
or organs
• To review basic microscope parts and lab techniques like
staining cells and preparing a wet mount for microscope slides
•
•
Shape
Components
Plant Cells
Rectangular
Cell wall
Cell Membrane
Nucleus
Animal Cells
Circular
Cell Membrane
Nucleus
Plant cells have structures not found
in animal cells
• Cell wall - help give
plants shape, support
and protection
• Chloroplast-site of
photosynthesis
• Large central vacuole contains water which
helps keep plant from
wilting; when the vacuole
is full it presses against
the cell wall to give the
plants rigidity (turgid
pressure)
Animal cells have structures not
found in plant cells
• Cytoskeleton- animal
cells use the
cytoskeleton to help
with support and aid
in movement
• Centrioles-aid in cell
division
Differences between
Plant/Animal Cells
Animal Cells
Centrioles
Plant Cells
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Cell Wall
Chloroplasts
Animal Cell
Nucleolus
Nucleus
Ribosome
(attached)
Nuclear
envelope
Ribosome
(free)
Cell
Membrane
Mitochondrion
Smooth
endoplasmic
reticulum
Rough
endoplasmic
reticulum
Centrioles
Golgi apparatus
Animal Cell
Plant Cell
Smooth endoplasmic
reticulum
Vacuole
Ribosome
(free)
Chloroplast
Ribosome
(attached)
Cell
Membrane
Nuclear
envelope
Cell wall
Nucleolus
Golgi apparatus
Nucleus
Mitochondrion
Rough endoplasmic reticulum
Plant Cell
Cell Specialization
•
•
•
•
Animal cells
Red Blood Cells- carries oxygen; small
and round to fit through vessels
Pancreatic Cells- produce enzymes to
break down food; contains many
ribosomes and rough ER to aid in this
process
Muscle Cells- long and threadlike to aid in
movement; contain many mitochondria for
energy production
Plant Cells
Guard cells- in the pores of leaves; aids in
water exchange
Cell Shape is Related to Function
Levels of Organization
Muscle cell
Smooth muscle tissue
Stomach
Digestive system
• Many multicellular organisms have structures called organs that
have a specific function and work with other organs.
• Working together, these organs carry out the life processes of
the entire organism.
• Multicellular organisms contains cells, tissues, organs and
organ systems
Microscopes
• What is a microscope and its parts?
• How do I properly use a microscope?
The Compound
Microscope
1. Eyepiece (ocular lens)
2. Arm
3. Stage
4. Opening of the stage
5. Fine adjustment knob
6. Coarse adjustment knob
7. Base
8. Illuminator
9. Diaphragm
10.Diaphragm lever
11.Stage clips
12.Low-power objective
13.High-power objective
14.Nosepiece
15.Body tube
Parts of the Microscope
and their Function
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Eyepiece Contains a magnifying lens
Arm Supports the body tube
Stage Supports the slide being observed
Opening of the stage Permits light to pass up to the eyepiece
Fine adjustment knob Moves the body tube slightly to sharpen
the image
Coarse adjustment knob Moves the body tube to focus the
image
Base Supports the microscope
Illuminator Produces light or reflects light up toward the
eyepiece
Diaphragm Regulates the amount of light passing up toward
the eyepiece
Diaphragm lever Opens and closes the diaphragm
Stage clips Hold the slide in place
Low-power objective Provides a magnification of 10× and is the
shortest objective
High-power objective Provides a magnification of 40× and is the
longest objective
Nosepiece Holds the objectives and can be rotated to change
the magnification
Body tube Maintains the proper distance between the eyepiece
M.
A.
L.
B.
C. (10x)
K.
D. (40x)
E.
J.
F.
I.
H.
G.