Transcript Cells - Building Directory

Cells
Holt Biology
Chapter 3
SOL BIO.2
The student will investigate and understand the history of
biological concepts. Key concepts include
• evidence supporting the cell theory;
• scientific explanations of the development of organisms
through time (biological evolution);
• evidence supporting the germ theory of infectious
disease;
• development of the structural model of DNA; and
• the collaborative efforts of scientists, past and present.
SOL BIO.4
The student will investigate and understand
relationships between cell structure and
function. Key concepts include
• characteristics of prokaryotic and eukaryotic
cells;
• exploring the diversity and variation of
eukaryotes;
• similarities between the activities of a single cell
and a whole organism; and
• the cell membrane model (diffusion, osmosis,
and active transport).
Thoughts to Ponder:
• 1.Are cells alive? Why do you think this?
• 2.Where are cells located in your body?
• 3.Where do the cells in your body get
energy?
• 4.How do your cells know what to do?
What directs their functioning?
Objectives
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Explain and apply cell theory.
Distiguish prokaryotic and eukaryotic cells
Distinguish plant and animal cells
Describe the appearance and function of the major
components of a cell, including: cell membrane,
cytoplasm, and the following membrane-bound
organelles: nucleus, rough and smooth endoplasmic
reticulum, mitochondria, chloroplast, and vacuole.
• Describe the appearance and function of some
subcellular structures, including ribosomes.
Cell Theory
• 1665-English Scientist: Robert Hooke
• Crude microscope to notice cork made of
tiny “boxes” he called cells
• 1675-Dutch Scientist: Anton van
Leeuwenhoek
• Microscope to view pond water—saw
“animacules” or tiny animals-plankton
Cell Theory
(based on these three scientists)
• 1838-German Botanist: Mattias Schleiden
• Cells make up all parts of a plant
• 1839-German Zoologist: Theodor Schwann
• Cells make up all parts of animals
• 1858-German Physician: Rudolph Virchow
• Cells come only from other cells
Cell Theory
• All living things are made of one or more
cells.
• All cells arise from pre-existing cells.
• Cells are the basic units of structure and
function in living organisms
Cells: Overview
• Most cells are very, very small, so tiny that they
can only be seen with the aid of a microscope.
• Your body is composed of billions of cells! Within
your body, cells have different functions. We
have blood cells, skin cells, brain cells...the list
goes on.
• Despite their differences, cells in living
organisms for the most part have similar
structures and functions.
• Question 1.Have you ever seen a cell? When?
What do you remember about it?
Stop
• Review volume section
of metric worksheet
Surface Area to Volume
Animal and Plant Cell parts
• cell membrane which serves as a boundary between
the cell and the outside environment
• cytoplasm containing organelles
• nucleus containing hereditary material (DNA)
• mitochondrion (plural, mitochondria), where cellular
respiration takes place (the breakdown of sugars to
produce energy for the cell, a process that uses oxygen
and produces carbon dioxide and water)
• smooth endoplasmic reticulum where lipids are made
• rough endoplasmic reticulum where proteins are
made with the help of ribosomes
Plants Only
• chloroplast which uses light energy to
convert six carbon dioxide molecules into
one organic six-carbon sugar
• cell wall outside the cell membrane which
provides additional strength
• vacuole, a large organelle containing
water, often with dissolved pigments,
waste materials, or other substances
Blood Cells and Fat Cells
(S.E.M)
Cells killing another cell
Review
(Answer in your notes)
• What are the four classes of large organic molecules
found in living things?
• Name two inorganic molecules that commonly occur
in living things.
• Name the 6 most common elements found in living
organisms.
• Carbohydrates/Lipids/Proteins/Nucleic
Acids
• Water, Sodium Chloride
• H2O, NaCl
• CHNOPS: carbon, hydrogen, nitrogen,
oxygen, phosphorous, sulfur
Drawing Cells
• Refer to a textbook to draw a simple diagram of an animal cell.
Draw to scale and label the following structures:
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Nucleus
Mitochondrion
Cell membrane
Cytoplasm
Ribosome
Rough endoplasmic reticulum (rough ER)
Smooth endoplasmic reticulum (smooth ER)
Golgi apparatus
Drawing Cells
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Refer to a textbook to draw a simple diagram of a plant cell. Draw to scale
and label the following structures:
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Cell membrane
Cell wall
Chloroplast
Cytoplasm
Mitochondrion
Nucleus
Ribosome
Vacuole
Rough endoplasmic reticulum (rough ER)
Smooth endoplasmic reticulum (smooth ER)
Golgi apparatus
Homework: Draw both cells and complete the
“To Do” and answer the question below
• Note that drawings can be misleading.
• For example, a drawing typically shows one or a
few mitochondria in a cell, but cells actually
contain many mitochondria, sometimes 10,000
or more.
• Also, drawings are two-dimensional whereas
cells are three-dimensional.
• To Do In your drawings, briefly note the
functions of each organelle.
• Question How are plant cells different from
animal cells? In what ways are they similar?
Animal Cell vs. Plant Cell
Animal vs. Plant Cell
• Create a Venn diagram that shows the
similarities and differences between plant
and animal cells
All Cells Have:
• Cell membrane
• Cytoplasm
• Cytoskeleton
• Ribosomes
Write the definitions in your notes, p. 56
SOL Prokaryotic and Eukaryotic
• Investigate and distinguish between eukaryotes and
prokaryotes based on observations of size, presence
of a defined nucleus, and the presence of organelles.
Prokaryotic Cells
(before-kernel or pre-nucleus)
• Write definition in your notes p. 57
• Do these kinds of cells have a membranebounded organelles, including a nucleus?
• Are prokaryotes simple and ancient?
• Did prokaryotes evolve before eukaryotes?
• Are bacteria prokaryotes?
• Are prokaryotes able to live in a variety of
environments?
Prokaryotic Cells
• Kingdoms: Archaebacteria and Eubacteria
• No membrane-bound organelles
• Enzymes and ribosomes move around the
cytoplasm freely
• Genetic material is a single, circular strand of
DNA
• Have a cell wall around the cell membrane
• Do prokaryotes have a cytoskeleton?
• How do these cells keep their shape?
• Describe prokaryotic flagella
Cell Wall
• Write definition in your notes, p. 57
• List organisms that also have a cell wall
but are eukaryotic
Eukaryotic
(well-kernel or with nucleus)
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Cells with a defined, membrane-bound nucleus
Nucleus
Organelle
Write out definitions in your notes p. 58
Cytoplasm: contains everything inside the cell
membrane but outside the nucleus
• List the major organelles seen in Fig. 7
Cytoskeleton
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What is the cytoskeleton?
What is it made of?
List some of its functions
List the 3 kinds of cytoskeleton fibers
List the functions of each of these fibers
Cell Membrane
p. 60
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Is the cell membrane rigid or fluid?
What is selective permeability?
Define phospholipid
Define lipid bilayer
Draw a cell membrane phospholipid
bilayer and label the polar heads and the
non-polar tails
Cell Membrane Chemistry
• What do the non-polar lipid tails repel?
• What do these tails allow to pass?
• How do membrane proteins stay in the bilayer?
(p. 61)
• Can proteins move around in the membrane?
• Name 4 kinds of proteins that are found in cell
membranes and give their functions
Organelle Structure-Function Chart
(SOL answers follow)
Organelle
Animal Plant
Structure
Function
SOL Structure and Function
of Cell Organelles
Relate the following essential cell structures to their
functions:
• nucleus (contains DNA, site where RNA is made)
• ribosomes (site of protein synthesis)
• mitochondria (site of cell respiration)
• chloroplast (site of photosynthesis)
• endoplasmic reticulum (transports materials through the
cell)
• Golgi apparatus (cell products packaged for export)
• lysosomes (contain digestive enzymes)
• cell wall (provides support)
Plasma Membrane
• A lipid/protein/
carbohydrate complex,
providing a barrier and
containing transport and
signalling systems.
Nucleus
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Double membrane
surrounding the
chromosomes and the
nucleolus. Pores allow
specific communication
with the cytoplasm. The
nucleolus is a site for
synthesis of RNA making
up the ribosome
Mitochondria
• Surrounded by a
double membrane
with a series of folds
called cristae.
Functions in energy
production through
metabolism. Contains
its own DNA, and is
believed to have
originated as a
captured bacterium.
Chloroplasts (plastids)
• Chloroplasts (plastids)
Surrounded by a double
membrane, containing
stacked thylacoid
membranes. Responsible
for photosynthesis, the
trapping of light energy
for the synthesis of
sugars. Contains DNA,
and like mitochondria is
believed to have
originated as a captured
bacterium.
Rough endoplasmic reticulum
(RER)
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A network of interconnected
membranes forming channels
within the cell. Covered with
ribosomes (causing the
"rough" appearance) which are
in the process of synthesizing
proteins for secretion or
localization in membranes.
• Ribosomes
Protein and RNA complex
responsible for protein
synthesis
Smooth endoplasmic reticulum
(SER)
• A network of
interconnected
membranes forming
channels within the cell. A
site for synthesis and
metabolism of lipids. Also
contains enzymes for
detoxifying chemicals
including drugs and
pesticides.
Golgi apparatus
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A series of stacked
membranes. Vesicles (small
membrane surrounded bags)
carry materials from the RER
to the Golgi apparatus.
Vesicles move between the
stacks while the proteins are
"processed" to a mature form.
Vesicles then carry newly
formed membrane and
secreted proteins to their final
destinations including
secretion or membrane
localization.
Lysosymes
• A membrane bound
organelle that is
responsible for
degrading proteins
and membranes in
the cell, and also
helps degrade
materials ingested by
the cell.
Vacuoles
• Membrane
surrounded "bags"
that contain water and
storage materials in
plants.
Peroxisomes or Microbodies
• Produce and degrade
hydrogen peroxide, a
toxic compound that
can be produced
during metabolism
Cell wall
• Plants have a rigid cell wall in addition to
their cell membranes.